UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2022

OR

Commission File Number 001-39409

ALLOVIR, INC.

(Exact name of Registrant as specified in its Charter)

Registrant’s telephone number, including area code: (617) 433-2605

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the @Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

The aggregate market value of the voting and non-voting common equity held by non-affiliates of the Registrant was $143.5 million based on the closing price of the shares of common stock on The Nasdaq Global Select Market on June 30, 2022, the last business day of the registrant's most recently completed second quarter. In determining the market value of non-affiliate common stock, shares of the Registrant’s common stock beneficially owned by officers, directors and affiliates have been excluded. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

The number of shares of Registrant’s Common Stock, par value $0.0001 per share, outstanding as of February 9, 2023 was 93,463,200.

DOCUMENTS INCORPORATED BY REFERENCE

Table of Contents

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Summary of Material Risks Associated with Our Business

Our business is subject to numerous risks and uncertainties that you should be aware of before making an investment decision, including those highlighted in the section entitled “Risk Factors.” These risks include, but are not limited to, the following:

The summary risk factors described above should be read together with the text of the full risk factors below, in the section entitled “Risk Factors” and the other information set forth in this Annual Report on Form 10-K, including our consolidated financial statements and the related notes, as well as in other documents that we file with the SEC. The risks summarized above or described in full below are not the only risks that we face. Additional risks and uncertainties not precisely known to us, or that we currently deem to be immaterial may also materially adversely affect our business, financial condition, results of operations and future growth prospects.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements other than statements of historical facts contained in this Annual Report on Form 10-K are forward-looking statements, including but not limited to, statements about:

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In some cases, you can identify forward-looking statements by the words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “objective,” “ongoing,” “plan,” “predict,” “project,” “potential,” “should,” “will,” or “would,” or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this report, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain, and investors are cautioned not to unduly rely upon these statements.

You should read the section titled “Risk Factors” set forth in Part I, Item 1A of this Annual Report on Form 10-K for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. As a result of these factors, we cannot assure you that the forward-looking statements in this Annual Report on Form 10-K will prove to be accurate. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.

You should read this Annual Report on Form 10-K, completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

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PART I

Item 1. Business.

Overview

We are a leading late clinical-stage cell therapy company developing highly innovative allogeneic T cell therapies to treat and prevent devastating viral diseases. Our innovative and proprietary virus-specific T cell, or VST, therapy platform allows us to generate off-the-shelf VSTs designed to restore immunity in patients with T cell deficiencies who are at risk from the life-threatening consequences of viral diseases. There is an urgent medical need for therapies to treat a large number of patients suffering from viral diseases who currently have limited or no treatment options. We are developing three innovative, allogeneic, off-the-shelf VST therapy candidates targeting 11 different devastating viruses. The most advanced is posoleucel, a multi-VST therapy that targets six viruses: adenovirus, or AdV, BK virus, or BKV, cytomegalovirus, or CMV, Epstein-Barr virus, or EBV, human herpesvirus 6, or HHV-6, and JC virus, or JCV. Posoleucel has the potential to fundamentally transform the treatment landscape for transplant patients by substantially reducing or preventing disease morbidity and mortality, thereby dramatically improving patient outcomes.

Posoleucel is being studied in three ongoing Phase 3 registrational trials for 3 distinct indications - the prevention of clinically significant infections from multiple viruses, the treatment of virus-associated hemorrhagic cystitis, or HC, and the treatment of AdV infections – all in allogeneic hematopoietic cell transplant, or HCT, patients who are at high risk for life-threatening viral infections from the six viruses targeted by posoleucel. We have successfully accelerated the multi-prevention study in recognition of the fact that prevention best addresses patients’ unmet medical needs. The three Phase 3 studies are expected to complete enrollment by the end of 2023, enabling potential data readouts from all three trials in 2024.

The three registrational trials were informed by the positive results of proof-of-concept studies with posoleucel for both treatment and prevention. In the CHARMS Phase 2 treatment trial, 95% of allogeneic HCT patients with one or more treatment-refractory infections achieved a clinical response with posoleucel. In the Phase 2 multi-virus prevention trial, posoleucel demonstrated a substantial reduction in the expected rate of clinically significant viral infections or diseases, with 88% of patients remaining free of clinically significant infections caused by any of the six viruses that posoleucel targets through the Week 14 primary endpoint.

In addition to the ongoing Phase 3 registrational studies, posoleucel has been studied in a Phase 2 proof-of-concept study for the treatment of BK viremia in kidney transplant patients. Positive topline results of this study were reported in February 2023, showing balanced safety across posoleucel and placebo groups and clinically meaningful greater viral load declines with posoleucel versus placebo. This is the first study of posoleucel in SOT patients, and the results of this trial will inform next steps for this potential indication as well as the company’s broader SOT strategy.

Based on the strength of the posoleucel Phase 2 data for both treatment and prevention, the FDA has granted posoleucel Regenerative Medicine Advanced Therapy (RMAT) designation for each of the three indications being evaluated in Phase 3 clinical trials – for the treatment of HC caused by BKV, for the treatment of AdV infection in adults and children following allo-HCT, and for the prevention of clinically significant infections and disease caused by posoleucel’s six target viruses. Similarly, based on data generated from the Phase 2 POC treatment trial and the critical medical need, the European Medicines Agency (EMA) has granted posoleucel PRIority MEdicines (PRIME) designation for the treatment of serious infections with AdV, BKV, CMV, EBV and HHV-6. Posoleucel was one of the first seven investigational therapies to receive both PRIME and RMAT designations and, to our knowledge, is the only investigational therapy to receive three RMAT designations. While these designations may not lead to a faster development process and do not increase the likelihood that a product candidate will receive approval from the FDA or EMA, we expect that PRIME and RMAT designations will result in increased EMA and FDA interactions to support our development efforts and may enable an expedited regulatory review process. In addition, the FDA also granted posoleucel Orphan Drug Designation for the treatment of virus-associated HC, and the EMA granted Orphan Medicinal Product designation to posoleucel for its targeted viruses in HCT patients, including for the potential prevention of infections or disease by these viruses.

In clinical trials conducted to date, we have treated more than 300 transplant patients with either single or multi-virus targeted allogeneic VSTs, and our product candidates have been generally well-tolerated and have been associated with clinical benefit. We believe that our allogeneic, off-the-shelf VSTs can benefit patients with other conditions characterized by T-cell deficiencies who are at high risk for life-threatening viral diseases, including immunocompromised cancer patients, the elderly and young children with immature immune systems. We are advancing a pipeline of VST therapies for delivery to individuals with compromised immune systems and those who are at high risk, or suffering from, the life-threatening consequences of viral diseases.

Our proprietary VST manufacturing platform enables the rapid, robust and reproducible generation of single-virus and multi-virus specific cell therapeutic candidates for clinical use. Our VST production process selectively expands polyclonal (CD4+ helper and CD8+ cytotoxic) virus-targeted T-cell populations. The critical components of our off-the-shelf VST platform, for which patents are issued and/or pending, include:

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We have applied this expertise in the development of additional product candidates that may benefit high-risk individuals:

If approved, we believe posoleucel has a large global market opportunity to treat and prevent devastating viral diseases. Based on the established epidemiology of our target Phase 3 indications, we estimate the addressable patient population for posoleucel will be approximately 41,000 HCT patients annually in 2025. The addressable patient population could expand beyond HCT patients into SOT patients as well as beyond the transplant setting to additional immunocompromised patients suffering from these devastating viral infections.

We are able to leverage ElevateBio’s cell therapy expertise to develop and manufacture VST therapies for clinical trials and commercialization. ElevateBio has established ElevateBio BaseCamp, Inc., or BaseCamp, a centralized cell and gene therapy development and manufacturing facility dedicated to the production of products for its affiliated companies.
 

Our management team has significant experience in successfully advancing products from early-stage discovery through commercialization. Our Chief Executive Officer, Diana Brainard, has more than 20 years of experience in the biopharmaceutical industry and academic medicine. During her 10-year tenure at Gilead Sciences, Diana served as the head of the virology therapeutic area, leading the development and launch of some of the most successful drugs of the last decade, including Sovaldi, Harvoni, Epclusa and Biktarvy. In 2020, she led the company-wide initiative to rapidly advance Veklury (remdesivir) to become the first and only antiviral to receive regulatory approval for the treatment of SARS-CoV-2, which earned her global recognition as one of the most influential people in the fight against SARS-CoV-2. Her industry career began at Merck, where she held positions in clinical pharmacology and experimental medicine. Diana also serves as an Independent Director of Nektar Therapeutics and Affinia Therapeutics.
 

Vikas Sinha, our President and Chief Financial Officer, brings more than 25 years of experience in executive finance roles within the biopharmaceutical industry. He served as the Chief Financial Officer of Alexion Pharmaceuticals for more than 11 years, where he oversaw the global expansion of the company across 50 countries and revenue growth to more than $3 billion. Prior to joining Alexion, Vikas held various positions with Bayer AG across the world, including CFO, Bayer Pharma, North America and CFO, Bayer Yakuhin, Japan. He also serves as Chief Financial Officer of ElevateBio and an Independent Director and Audit Committee Chair at Verona Pharma.
 

To date, we have raised $156.9 million in aggregate gross proceeds through private financings, $317.7 million in aggregate gross proceeds through our IPO, which closed in August 2020, and $126.6 million in aggregate gross proceeds through a registered direct offering in July 2022.

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Our Pipeline

We are advancing a pipeline of three allogeneic off-the-shelf VST therapy candidates targeting 11 different viruses to treat and prevent life-threatening viral diseases. For each of these pipeline therapies, we have global development and commercialization rights. The chart below summarizes key information about our programs.

Promising efficacy and safety results from the completed Phase 2 treatment and prevention trials in allogeneic HCT patients enabled the rapid progression of posoleucel into Phase 3 development. In the CHARMS Phase 2 POC treatment trial, 95% of allogeneic HCT patients with infections from one or more of the target viruses and who previously failed or were intolerant to conventional antiviral treatments, achieved a clinical response when treated with posoleucel therapy. In the Phase 2 multi-virus prevention trial, posoleucel demonstrated a substantial reduction in the expected rate of clinically significant viral infections or diseases, with 88% of patients remained free of clinically significant infections caused by any of the six viruses that posoleucel targets through the Week 14 primary endpoint.

A Phase 2 POC trial of posoleucel to treat BK viremia in kidney transplant patients completed in 2022. Positive topline data from the BKV study were reported in February 2023, showing balanced safety across posoleucel and placebo groups and clinically meaningful greater viral load declines with posoleucel versus placebo.

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Our Strategy

Our goal is to extend our leadership position in the development of allogeneic, off-the-shelf VST-cell therapies to serve patients at risk of the life-threatening consequences of severe viral diseases. To achieve this, we are pursuing the following strategies:

ALVR106 is already in the clinic, with a POC trial currently enrolling transplant patients in the U.S. We believe that ALVR106 has the potential to transform the treatment of respiratory viruses and substantially reduce the severity of respiratory infections while improving patient outcomes. While ALVR106 is currently being studied in transplant patients suffering from respiratory viral infections, our goal is to expand to other high-risk patient populations, such as immunocompromised cancer patients, the very young and the elderly. In addition, we have completed preclinical and IND-enabling studies of ALVR107 as a potential cure for chronic HBV infections, and plan to move ALVR107 into clinical development after completing the posoleucel Phase 3 studies. And we have demonstrated our ability to rapidly initiate the development of and progression into the clinic of a VST therapy in response to emerging pathogens, with the SARS-CoV-2 specific VST therapy candidate ALVR109.

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The Immune System and the Role of T Cells

In healthy individuals, the adaptive immune response forms a critical component of the body’s natural defense system and provides protection against numerous disease-causing viruses, as depicted in the figure below. Certain types of T cells have an essential role in driving the immune response to viruses. The major role of CD8+ “cytotoxic” T cells is to kill virus-infected or otherwise diseased cells, while the major role of CD4+ “helper” T cells is to produce soluble proteins, known as cytokines, which produce direct antiviral effects and support CD8+ T-cell survival. CD4+ T cells can also signal other immune cell types, including antibody-producing B cells, thereby influencing the broader antiviral immune response. CD8+ and CD4+ T cells are vital components in maintaining adaptive immunity against many devastating viruses.

Figure 1. T cells play a central role in response to viral infection

T cells recognize viruses via their T-cell receptors, or TCRs, which selectively recognize “foreign” viral peptides displayed by a compatible “self” human leukocyte antigen, or HLA, proteins present on the surface of virus-infected cells or antigen presenting cells. Once T cells bind to the peptide-HLA complex, they become activated and start to multiply as the body mounts an immune response to control or eliminate the virus. In contrast, if the peptide displayed by the HLA allele is not “foreign” but instead from a “self” antigen, then T cells do not bind to the cell and no immune response is generated.

To be clinically effective, at least a portion of the infused, allogeneic, off-the-shelf VSTs must be compatible, or partially HLA matched, with the patient so that some of the infused T cells can bind to viral peptide-HLA complexes, resulting in selective antiviral effects against virus-infected cells.

While HLA alleles provide a defining feature of an individual’s biology, there are only a limited number of unique HLA types among humans. This important characteristic has allowed us to develop allogeneic VSTs from donors who are carefully chosen to provide HLA coverage to the broad patient population at risk of devastating viral infections.

VST therapies are specifically designed to enhance and restore T-cell function. In patients with T-cell deficiencies, uncontrolled viral infection, replication and expansion can result in severe and devastating consequences.

Transplantation and Immunosuppression

There are two major types of transplant procedures: HCTs and SOTs. In each procedure, the immune system of the patient is suppressed or eliminated to prevent rejection of the transplanted cells or organs. In the case of HCT, this immunocompromised state is

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typically temporary and resolves once the transplanted donor stem cells begin to replenish the cells of the immune system. In SOT, most patients require a high dose of immunosuppressive drugs for the first six months post-transplant and some degree of immunosuppressive treatment for the rest of their lives.

HCTs are clinical procedures used in the treatment of severe and life-threatening diseases primarily of the blood and immune systems, including some forms of leukemia and lymphoma, genetic diseases and other blood-based diseases. In HCTs, physicians remove diseased or, in the case of some genetic diseases, missing blood cells, along with the stem cells that lead to their formation. The physician then replaces the diseased or missing blood cells with healthy red and white blood cell-forming stem cells from donors. The process of destroying the defective cells, known as conditioning, also leads to the depletion of the patient’s immune cells, leaving patients highly vulnerable to disease-causing viruses, which can become life-threatening due to their weakened immune systems. Patients can remain vulnerable for an extended period until the donor stem cells take up residence and begin to reconstitute a functional immune system. A key challenge in HCT is the identification of transplant material that is immunologically compatible with the patient. The selection of donors for HCT procedures requires that the donor’s HLA antigens comprise a close match to those of the patient, as an exact match is not often available. Procedures using more stringent conditioning enable these patients to receive partially matched stem cells from allogeneic donors. This more stringent conditioning, known as myeloablative conditioning, leaves the patient extremely immunosuppressed and highly prone to potentially deadly viral diseases.

In up to 90% of allogeneic HCT patients, the suppressed immune system allows viruses that were previously in a latent, quiescent state to reactivate and more than 60% of allogeneic HCT patients experience a reactivation of more than one virus, including BKV, CMV, AdV, EBV and HHV-6, as depicted in the figure below. In healthy, immunocompetent individuals, these viruses typically lead to mild, self-limiting infections. However, in immunocompromised patients, once reactivated, each of these viruses has the potential to cause significant morbidity and even mortality. It is estimated that more than 20% of all deaths associated with HCTs are due to infections.

Figure 2. Approximately 90% of patients undergoing allogeneic HCT have at least one viral infection and 62% have more than one. Multiple viruses contribute to significant mortality

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SOT has been established as a definitive treatment option for patients with organ failure. Over the past few decades, SOT procedures have rapidly progressed and now include a variety of solid organs, including the kidney, lung, liver, heart, intestine and pancreas. The increase in organ transplants has been matched by improved short- and long-term graft survival. This is due, in large part, to the use of immunosuppressive drugs that prevent the immune system from rejecting the transplanted organ. However, typically SOT patients require some degree of immunosuppressive therapy life-long, which leaves them vulnerable to viral infections and disease for a longer duration than HCT patients. In addition, high-risk SOT patients, including recipients of organs mismatched at a high number of HLA antigens, highly sensitized recipients, or ABO blood type incompatible recipients, tend to receive more rigorous immunosuppressive induction treatment, further increasing the risk of these patients contracting potentially deadly viral diseases. Further, SOT patients with the viral infections and diseases our product candidates aim to treat or prevent, suffer from worse outcomes, including graft failure, despite current standard of care treatment, as depicted in the figure below.

Figure 3. BKV in kidney transplant recipients leads to decreased graft survival despite standard of care

We believe transplant patients represent one segment of the large number of immunocompromised patients suffering from devastating viral infections who could potentially benefit from allogeneic, off-the-shelf VST therapies. Other individuals with weakened immune systems, including those with primary immunodeficiencies, the elderly and very young and patients who have compromised immune systems due to cancer or the treatment of their cancer are all at high risk of the life-threatening consequences of viral diseases and infections. Each of these target patient populations represents a large potential market that is currently untapped or underserved by existing therapies.

Limitations of Current Therapies for Immunocompromised Patients

There are no FDA- or EMA-approved antiviral drugs to treat the majority of the diseases and patients we are planning to target using our allogeneic off-the-shelf VSTs. When used clinically, available antivirals are often ineffective, toxic, can lead to emergence of virus escape mutants that are treatment-refractory and despite their use patients often succumb to their infections.

Similarly, there are limitations to prophylactic approaches, such as vaccines, in immunosuppressed patients, the elderly, and the very young who may be unable to mount an effective immune response that protects against the target viruses.

In contrast, the adoptive transfer of ex vivo expanded VSTs to HCT patients has generated promising preliminary disease outcome measures and safety data in treating a range of viral diseases in clinical trials. We designed an approach whereby VSTs could be prospectively generated from healthy, third-party donors expressing common HLA polymorphisms who were seropositive for all of the

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targeted viruses. These VSTs were prepared by stimulating peripheral blood mononuclear cells, or PBMCs, with viral antigens followed by ex vivo expansion and cryopreservation to enable utilization when needed by patients. We then clinically assessed whether such allogeneic VSTs, when administered as a partially HLA-matched off-the-shelf therapy could still provide clinical benefit in a safe manner. We have treated more than 300 allogeneic HCT patients with either single or multi-virus targeted allogeneic VSTs. These off-the-shelf VSTs have been generally well-tolerated and were associated with clinical benefit as indicated by the high response rate demonstrated in immunocompromised patients with drug-refractory infections and diseases.

Our Approach to Allogeneic Off-the-Shelf T-Cell Immunotherapy

There is an urgent medical need for therapies to treat a large number of patients suffering from devastating viral diseases who currently have limited or no treatment options. Our approach involves the restoration of viral immunity through the adoptive transfer of VSTs, which have been prospectively generated from healthy, eligible donors. These cells are immediately available for “off-the-shelf” administration to patients at risk from the devastating consequences of viral diseases due to T-cell deficiencies, as depicted in the figure below. The partial HLA match between the allogeneic VST therapy and infected patient allows the infused T cells to recognize and selectively kill virus-infected cells while leaving non-virus-infected host cells intact, thereby minimizing the risk of therapy-associated graft-versus-host disease, or GVHD.

Figure 4. Adoptive transfer of off-the-shelf VSTs kill virus-infected cells and restore virus-specific T-cell immunity

Our VSTs are generated from a panel of healthy, third-party blood donors that collectively express a diverse array of HLA allele subtypes. Collectively, these VSTs, which therefore recognize viral peptides displayed by an array of different HLA alleles, form a mini-bank of product candidates that provide coverage to more than 95% of patients in our targeted populations. These VSTs can be stored in a cryopreserved state and thus supplied rapidly and globally as an off-the-shelf therapy for patients suffering from, or at risk for contracting, one or more viral diseases.

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Using our versatile and robust off-the-shelf VST platform, we are able to rapidly generate VST therapies for the treatment of a spectrum of viral diseases. This is demonstrated by our pipeline of four innovative, allogeneic off-the-shelf VST therapy candidates targeting both multi-virus (posoleucel and ALVR106) and single-virus indications (ALVR109 and ALVR107). Our portfolio not only showcases our potential to target multiple devastating viral diseases, but also highlights our ability to rapidly respond to emerging viruses, as evidenced by our COVID-19 program, and extend allogeneic off-the-shelf VST therapies beyond transplant patients in order to treat others at high risk of developing viral diseases.

Figure 5. AlloVir’s versatile off-the-shelf VST manufacturing platform

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Our Proprietary Allogeneic VST Therapy Process

We are uniquely positioned to rapidly develop and implement T-cell therapies to treat and/or prevent a range of viral diseases, given our team’s extensive experience in the fields of virology, immunology and cell therapy. We have leveraged this expertise to design the robust and reproducible allogeneic VST therapy production process depicted in the figure below. This process is comprised of three steps that enable the reliable generation of allogeneic, off-the-shelf, single or multi-virus-specific T cells: (1) our virus-specific T-cell profiling and targeted donor selection process, CytokinTM; (2) rapid and scalable off-the-shelf VST manufacturing; and (3) our proprietary, customized VST-cell line selection process, CytomatchTM, which allows for rapid patient access to our allogeneic VST therapy.

Figure 6. Key advantages of AlloVir’s patented, highly efficient and industrialized VST platform

Step 1: Profiling T-Cell Responses to Viruses and Donor Selection

Identifying immunodominant viral antigens and selecting targeted donors, using CytokinTM, from whom to generate VSTs specific for these immunodominant viral antigens.

To define a hierarchy of immunodominance, we first analyze the T-cell immune response present in healthy individuals who have naturally controlled a viral infection. To delineate which viral antigens induce the strongest T-cell immune responses we evaluate two parameters: (1) the number of donors whose T cells recognize each of the expressed viral antigens and (2) the strength of the T-cell response induced by each antigen, as measured using functional assays such as production of cytokines. Using these parameters, we can establish a hierarchy of immunodominance and determine which antigens to select for incorporation into our VST manufacturing process. We identify and advance at least two viral antigens in each target virus. This allows us to generate polyclonal VSTs that recognize multiple parts of each of the target viruses, thereby minimizing the risk of virus immune escape with our product candidates.

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Donor Selection—CytokinTM

We next apply our CytokinTM algorithm, as depicted in the figure below, to select the optimal combination of donors from whom to generate VSTs. CytokinTM compares the HLA types of our targeted patient population with a pool of diverse healthy, eligible seropositive donors and identifies a subset of donors, or a mini-bank, that collectively provide greater than 95% of all patients with an appropriate partially HLA-matched VST line. To ensure redundancy and that each patient has multiple VST line options, we build one or more additional mini-banks using the same strategy. In this way, we can assure both breadth and depth of patient coverage with our VST bank.

Figure 7. Implementing the CytokinTM algorithm to efficiently select donors from whom to generate mini-banks of VSTs

Step 2: Rapid and Scalable Off-the-Shelf VST Manufacturing

Applying our patented manufacturing platform to selectively, efficiently and rapidly expand polyclonal VSTs that are cryopreserved and available as an off-the-shelf therapy

To selectively activate and expand VSTs, we stimulate donor peripheral blood mononuclear cells, or PBMCs, with overlapping peptide libraries spanning immunodominant viral target antigens, in cell culture medium supplemented with growth factors for a period of approximately two weeks. During this timeframe, polyclonal VSTs are stimulated and expand while T cells that could potentially react with non-virus-infected patient cells and cause toxicities such as GVHD are deselected. In addition, for each virus we target at least two viral antigens in order to minimize the risk of virus immune escape. Once generated, these VSTs are stably maintained in a cryopreserved state allowing for immediate patient access. Each manufacturing run from an individual donor yields hundreds of product candidate doses.

Our ability to generate allogeneic, off-the-shelf VSTs in a single expansion step allows us to minimize antigen competition and preserve polyclonality. As a result, our polyclonal VSTs are comprised of both helper (CD4+) and cytotoxic (CD8+) virus-specific T cells that recognize multiple parts of each of our target viral antigens, or viral peptides, presented by different HLA alleles. As a result, we can deliver our product candidate to patients based on partial HLA match. The partial HLA match between the allogeneic VST-cell line and infected patient allows the infused T cells to recognize and selectively kill virus-infected cells.

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To facilitate investigational product supply for our clinical trials, we currently manufacture posoleucel and ALVR106 at external cGMP CMOs and leverage a network of cGLP contract testing laboratories. We are also able to leverage ElevateBio’s cell therapy expertise to develop and manufacture VST therapies for clinical trials and commercialization. ElevateBio has established ElevateBio BaseCamp, Inc., or BaseCamp, a centralized cell and gene therapy development and manufacturing facility dedicated to the production of products for its affiliated companies. Therefore, we have also added ElevateBio BaseCamp to our manufacturing network.

Step 3: CytomatchTM and Immediate Patient Access to Our Allogeneic VST Therapy

Rapidly identifying the appropriate VST line for each patient using the CytomatchTM algorithm, ensuring immediate accessibility to therapy for high-risk patients

The final component of our process relates to the clinical use of our allogeneic off-the-shelf VST therapy. The CytomatchTM algorithm guides the selection of the VST cell line for patient treatment. A specific drug product lot is selected for infusion based on the level of HLA matching between patient and associated VST-cell line, with two HLA allele matches set as a minimum threshold. The “best” VST-cell line is rapidly identified and can be immediately packed and shipped to the treatment center, where it can be thawed and infused to patients without the need for additional manipulation.

Our Highly Innovative Allogeneic VST Therapy Candidates

Our pipeline of allogeneic, off-the-shelf VST therapy candidates is designed to restore virus-specific T-cell immunity in patients suffering from, or at risk for, life-threatening viral diseases. Our proprietary VST therapy platform can be used to generate allogeneic cell therapies targeting single or multiple viruses at commercial scale. We own worldwide development and commercialization rights to all our cell therapies.

Figure 8. AlloVir’s pipeline

Posoleucel

Our lead product candidate, posoleucel, is a multi-VST therapy targeting six viral pathogens: AdV, BKV, CMV, EBV, HHV-6 and JCV, which has the potential to fundamentally transform the treatment landscape for immunocompromised individuals.

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We are initially focusing the development of posoleucel in immunocompromised HCT and SOT patients who are at high risk for life-threatening viral infections and are focused on the use of posoleucel as follows:

Posoleucel is designed to restore virus-specific T-cell immunity and eradicate active viral infections and associated morbidities. We believe that posoleucel has the potential to fundamentally transform the management of viral infections in HCT and SOT patients, as well as in other individuals at high risk for opportunistic infections. We believe that posoleucel will substantially reduce or prevent virus-associated morbidity and mortality and dramatically improve outcomes for patients with otherwise devastating viral diseases.

Based on the strength of the posoleucel Phase 2 data for both treatment and prevention, the FDA has granted posoleucel Regenerative Medicine Advanced Therapy (RMAT) designation for each of the three indications being evaluated in Phase 3 clinical trials – for the treatment of HC caused by BKV, for the treatment of AdV infection in adults and children following allo-HCT, and for the prevention of clinically significant infections and disease caused by posoleucel’s six target viruses. Similarly, based on data generated from the Phase 2 POC treatment trial and the critical medical need, the European Medicines Agency (EMA) has granted posoleucel PRIority Medicines (PRIME) designation for the treatment of serious infections with AdV, BKV, CMV, EBV and HHV-6. Posoleucel was one of the first seven investigational therapies to receive both PRIME and RMAT designations and, to our knowledge, is the only investigational therapy to receive three RMAT designations. While these designations may not lead to a faster development process and do not increase the likelihood that a product candidate will receive approval from the FDA or EMA, we expect that PRIME and RMAT designations will result in increased EMA and FDA interactions to support our development efforts and may enable an expedited regulatory review process. In addition, the FDA also granted posoleucel Orphan Drug Designation for the treatment of virus-associated HC, and the EMA granted Orphan Medicinal Product designation to posoleucel for its targeted viruses in HCT patients, including for the potential prevention of infections or disease by these viruses.

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Posoleucel for Allogeneic HCT Patients

HCT conditioning regimens often require the complete elimination of a patient’s own stem cells, a procedure referred to as myeloablation. These patients are left without a functioning immune system and are consequently in a severely immunocompromised state until their donor stem cells take hold, or engraft, and repopulate the bone marrow. During this period, these patients are highly susceptible to infection. We believe that, as depicted in the figure below, our VST therapy candidates can play the key role of providing bridging immunity between myeloablation, where patients have little-to-no immune function of their own, and reconstitution of their immune systems after the donor stem cells engraft and expand to physiologic levels. We believe that by restoring immunity during this time of severe immune compromise, our VST therapy candidates may substantially reduce or prevent virus-associated morbidity and mortality, thereby dramatically improving patient outcomes.

Figure 9. Posoleucel is designed to treat and prevent viral diseases until the patient’s own immune system recovers

In approximately 90% of allogeneic HCT patients, the suppressed immune system allows viruses that were previously in a latent, quiescent state to reactivate. Furthermore, more than 60% of allogeneic HCT patients experience a reactivation of more than one virus targeted by posoleucel. These viral infections can cause multi-organ disease and multi-organ failure that may be life-threatening and that typically require hospitalization. It is estimated that more than 20% of all deaths associated with HCTs are due to infections. There are currently no FDA- or EMA-approved therapies for treating most viral infections in the post-transplant setting, and current antiviral therapies are associated with significant toxicity, including renal insufficiency and bone marrow suppression.

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Posoleucel Phase 2 POC CHARMS Clinical Results in Allogeneic HCT Patients

We evaluated posoleucel in a Phase 2 open-label POC trial where VSTs were administered to 58 allogeneic HCT patients with treatment-refractory infections. We refer to this trial as CHARMS.

The primary objective of CHARMS, which was not statistically powered for superiority or significance, was to determine the feasibility and safety of administering partially HLA-matched multi-VST therapies targeting six viruses in HCT patients with persistent viral reactivations or infections. Patients were eligible following any type of allogeneic transplant if they had AdV, BKV, CMV, EBV, HHV-6 and/or JCV infections that were relapsed, reactivated or persistent despite standard antiviral therapy.

Figure 10. CHARMS—Phase 2, proof-of-concept, open-label trial design

The treatment schedule encompassed an initial single infusion of 2 x 107 partially HLA-matched multi-VSTs/m2. If the patients had a partial response, or a PR, within 28 days of the first infusion, as defined by a 50% or greater fall in viral load, they were eligible to receive up to four additional doses from day 28 after the initial infusion and at two weekly intervals from day 28.

Efficacy endpoints for CHARMS were resolution of the target infections, as measured by viral load, and resolution of clinical signs and symptoms, as determined by the primary investigator. Clinical and virologic responses were assessed by week 6 per protocol and at additional timepoints where feasible. A complete response, or CR, was defined as return of viral load to normal range and resolution of clinical signs and symptoms. A PR was defined as a decrease in viral load of at least 50% from baseline or 50% improvement in clinical signs and symptoms. No response, or NR, was defined as either stable or progressive disease.

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The demographics and clinical characteristics for the 58 unique patients enrolled and treated in the CHARMS trial are presented in Table 1. These patients were infused with posoleucel therapy matched at one to seven HLA alleles. In this clinical trial, we observed the delivery of partially HLA matched VSTs were generally well-tolerated. These final trial results were published in Clinical Cancer Research in January 2023.

a The CHARMS trial treated 58 unique patients. One patient was enrolled twice, treated first for AdV and then for JCV. This patient was counted twice for some efficacy and once for safety. One patient with HHV-6 was not evaluable for response rate.

Table 1. CHARMS clinical trial patient demographic and clinical characteristics

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Clinical and Virologic Response

Of the 58 unique patients evaluated for efficacy by six weeks post infusion, 55 had a CR or PR, representing a 95% response rate, as depicted in the figure below. Twelve patients were co-infected with at least two different viruses and of these, ten patients (83%) responded to posoleucel by six weeks post-infusion. This demonstrates the potential for treating patients with multiple viral infections with off-the-shelf posoleucel.

Figure 11. Posoleucel Phase 2 proof-of-concept trial (CHARMS): 95% overall response rate in patients with viral disease by 6 weeks in 58 unique patients

In Vivo VST Persistence

In order to provide bridging immunity to HCT patients, allogeneic off-the-shelf VSTs must persist and provide continued antiviral protection until the transplanted stem cells engraft and the patient’s own immune function is restored. To examine how long our posoleucel cells persisted in patients, we examined the peptide epitope specificity of circulating T cells to discriminate between infused and endogenous virus-specific T cells. Of 16 patients that we tested, we were able to confirm the persistence of allogeneic VSTs in 11 patients for up to 12 weeks.

Safety Profile

The overall analysis of preliminary safety results gathered in the CHARMS trial showed that treatment with posoleucel was generally well-tolerated.

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Safety monitoring in the CHARMS trial consisted of several assessments, including assessments of both GVHD and serious adverse events, or SAEs, as reflected in the table below. Overall, 23 deaths occurred during the study; none of these deaths was deemed related to study treatment. Of the 23 deaths, 6 were associated with treatment-emergent AEs (TEAEs), and 5 deaths occurred during the protocol-specified AE reporting period. Treatment-related TEAEs ≥ Grade 3 occurred in 8 (13.8%) participants, however there were no TEAEs leading to interruption or discontinuation of study intervention, there were no dose-limiting toxicities, and no deaths were attributed to treatment-related TEAEs.

In general, safety findings were consistent with those expected in an allogeneic HCT patient population with persistent and/or refractory viral infections, including the known risks of GVHD. To date, no overt safety signal has been detected above and beyond the safety findings expected to be found in patients who have already undergone allogeneic HCT.

Table 2. Serious adverse events and GVHD in the CHARMS trial

Treatment of Virus-Associated Hemorrhagic Cystitis

HC is the primary clinical manifestation associated with BKV following HCT, occurring in 8-25% and 7-54% of pediatric and adult patients, respectively. HC can also be caused by other viruses, including AdV and CMV. However, up to 90% of cases of HC are caused by BKV.

Between 65-90% of individuals are infected with BKV by the age of ten. Most infections are asymptomatic, but the virus remains latent in the body, primarily in kidney cells throughout life. BKV can reactivate during periods of immune compromise with the virus being detected in the urine of over half of HCT patients.

More than half of patients with HC present with clot formation and/or severe bladder hemorrhage with renal impairment. Bleeding may be life-threatening requiring urologic interventions including the removal of the urinary bladder, or cystectomy. Clinical manifestations of HC include kidney dysfunction or failure, bright red-colored urine due to the presence of blood in the urine, as well as abdominal pain so severe and debilitating that patients often require continuous narcotic infusions.

A recent, prospective, multi-center trial of the natural history of BKV after allogeneic HCT in 193 patients found that:

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There are currently no FDA- or EMA-approved therapies for virus-associated HC. The current standard of care relies on supportive care to address the symptoms and manifestations of HC; urinary bladder irrigation to avoid its obstruction by blood clots; narcotics to alleviate suffering; hyperbaric oxygen therapy; cystectomy in uncontrollable bleeding cases; and dialysis for acute renal failure. The antiviral cidofovir is sometimes used off-label to treat virus-associated HC. However, cidofovir has been associated with kidney toxicity, which may compound the kidney damage caused by virus-associated HC itself.

Posoleucel Clinical Data—BKV

In our Phase 2 proof-of-concept trial for posoleucel, we treated 27 evaluable patients with BKV disease and 100% achieved an overall response by six weeks post-infusion. Overall response rates were defined as achieving either a PR or CR by six weeks post-infusion, as described in the protocol criteria.

In 23 patients infused with posoleucel, HC severity was retrospectively graded using the National Cancer Institute cystitis grading scale. This was performed by three physicians independently based on chart review of clinical and laboratory documentation. These patients treated with posoleucel therapy showed a rapid improvement in disease severity; complete resolution of macroscopic hematuria was observed in 43%, 61% and 74% of patients weeks 2, 4 and 6 post-infusion.

Figure 12. Time to resolution of BKV-HC following treatment with posoleucel

In a retrospective study conducted at BCM, out of 33 pediatric allogeneic HCT patients with an average of Grade 3 BK-HC receiving current standard of care, only 36% had resolved their disease by week 6. Furthermore, less than 10% of the patients had resolved their disease by week 2.

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We believe our data provide preliminary evidence demonstrating that posoleucel has the potential to meet unmet medical needs in allogeneic HCT patients with virus-associated HC.

Clinical Development Plan

We have initiated our Phase 3 virus-associated-HC registrational trial. This Phase 3, multicenter, randomized, double-blind, placebo-controlled trial is designed to assess the safety and efficacy of posoleucel therapy compared to placebo for the treatment of patients with virus-associated HC following allogeneic HCT. The primary endpoint is the time to resolution of macroscopic hematuria. As these HCT patients often experience multiple viral infections, secondary endpoints include the reduction in viral load for AdV, CMV, EBV, HHV-6 and JCV.

Figure 13. Phase 3, multicenter, randomized, double-blind, placebo-controlled virus-associated HC trial design

In addition to the PRIME and orphan drug designations granted by the EMA, posoleucel has received an RMAT designation from the FDA for the treatment of HC caused by BKV in adults and children following an allogeneic HCT. We expect that RMAT designation will result in increased FDA interactions to support our development efforts and may enable an expedited regulatory review process for product approval.

Treatment of Adenovirus Infections

AdV viremia occurs in 32% of pediatric allogeneic HCT patients and 6% of adult allogeneic HCT patients. In the HCT setting, patients can present with AdV disease due either to reactivation or de novo exposure. Infection usually occurs between two and three months post-transplant and is a significant cause of morbidity and mortality. The spectrum of AdV-associated disease in HCT patients ranges from mild gastroenteric or respiratory symptoms to severe hemorrhagic enteritis, hemorrhagic cystitis, nephritis, hepatitis, pneumonia, encephalitis, myocarditis, and potentially lethal multiple organ involvement, frequently associated with hepatic failure. Off-label use of cidofovir has been established as the current standard of care treatment to control the replication of virus and prevent disseminated viremia. However, it has limited efficacy irrespective of dose and its use is limited due to toxicity to the kidneys and poor bioavailability. To date, no adequately powered, randomized well-controlled trials demonstrating significant efficacy of cidofovir use for adenoviral disease versus control have been performed.

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Posoleucel Clinical Data—AdV

In our CHARMS trial, 83% of patients with AdV infection achieved a response by six weeks post-infusion.

Clinical Development Plan

We initiated our Phase 3 AdV trial at the end of 2021. The Phase 3 trial is a multicenter, randomized, double-blind, placebo-controlled trial designed to assess the safety and efficacy of posoleucel therapy for the treatment of pediatric and adult allogeneic HCT patients with AdV infection.

Figure 14. Phase 3, randomized, double-blind, placebo-controlled adenovirus treatment trial design

Prevention of Multi-Virus Infection and Associated Disease in HCT Patients

Approximately 90% of all allogeneic HCT patients experience at least one infection associated with BKV, CMV, AdV, EBV or HHV-6 and more than 60% of patients experience infections caused by two or more of these five viruses within 100 days post-allogeneic HCT. Because of the increased morbidity and mortality associated with viral infections in transplant patients, prevention of viral disease is important for the overall health and survival of patients. Prophylactic therapy, which is a treatment administered to patients at risk for developing viral disease, and preemptive therapy, a treatment of patients with evidence of virus replication in blood, are the two major strategies used for disease prevention. Clinical guidelines recommend that allogeneic HCT patients infected with CMV or AdV should be monitored weekly for virus replication with a sensitive diagnostic technique for at least the first three months after HCT. There are currently no FDA- or EMA-approved antiviral therapies for prevention of multiple viral diseases or infections in transplant patients with one single therapy. For CMV alone, letermovir is approved for CMV in seropositive patients. However, drug resistant CMV has emerged with the use of letermovir, which may limit or restrict its utility.

Posoleucel Clinical Data—Multi-Virus Prevention in HCT Patients

Out of 26 high-risk allo-HCT patients who received posoleucel in this open-label study, 22 (85%) patients experienced reactivation of at least one of posoleucel’s target viruses. Despite these expected high rates of viral reactivation, only three clinically significant infections were observed through Week 14. These results represent a substantial reduction in the expected rate of clinically significant viral infections or diseases in this high-risk patient population. Biomarker analyses demonstrated that viral control was associated with expansion of functional VSTs, and the presence of posoleucel was confirmed both during the infusion period and up to 14 weeks after

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the last infusion.
 

Treatment with up to seven doses of posoleucel over 12 weeks was generally well tolerated with no unanticipated safety signals. Rates of GVHD were similar in frequency and severity to those expected in this high-risk allo-HCT population. Three (12%) treatment-related serious adverse events were reported. No episodes of cytokine release syndrome were reported.
 

Clinical Development Plan

Based on preliminary data from the open-label, Phase 2 POC study for multi-virus prevention, we initiated a global, registrational Phase 3 multicenter, randomized, double-blind, placebo-controlled clinical trial of posoleucel for multi-virus prevention. The study is enrolling patients in North America, Europe, Asia and Australia.

Figure 15. Phase 3, randomized, double-blind, placebo-controlled multi-virus prevention trial design

Treatment of BKV Infections in Kidney Transplant Patients

BK virus reactivation in KT patients is due to T-cell immune deficiencies caused by intensive immunosuppressive induction therapy followed by maintenance immunosuppressive treatment. BKV reactivation causes interstitial nephritis and progressive allograft injury. Routine screening for BKV reactivation after transplantation has been widely recommended and is performed at most transplant centers. The goal of diagnosing and managing BK viremia early in the course of active infection is to prevent allograft failure that is associated with BKV-associated nephropathy. BK viremia is detected in up to 20% of KT patients and up to 50% of patients with BK viremia progresses to BK nephropathy, resulting in decreased graft function and graft survival. Nearly half of all patients who develop BK nephropathy experience allograft failure. Because KT patients remain on immunosuppression for life, BK viremia and BK nephropathy onset is not restricted to the first year post-transplant. There are currently no FDA- or EMA-approved therapies for the treatment of BK viremia or BK nephropathy in KT patients. Treatment primarily involves reduction of immunosuppression. However, this results in patients being at increased risk of immune mediated acute allograft rejection.

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Posoleucel Clinical Data— BKV Treatment in Kidney Transplant Patients

At the end of last year, we completed a proof-of-concept, multi-center, randomized, double-blind, placebo-controlled, Phase 2 trial evaluating posoleucel for the treatment of BKV in KT patients.

Figure 16. Phase 2, randomized, double-blind, placebo-controlled BK virus treatment in kidney transplant trial design

The primary endpoint of the posoleucel Phase 2 BKV treatment study in kidney transplant patients with BK viremia was the safety and tolerability of posoleucel versus placebo. Posoleucel was generally well tolerated in the study, with balanced safety across posoleucel dosing groups and placebo, and adverse events rates and severity consistent with the underlying patient population and background immunosuppression. Low rates of infusion reactions were observed in patients receiving posoleucel (2%) and those receiving placebo (5%). There were no deaths or reports of graft versus host disease or cytokine release syndrome. Emergence of donor-specific antibodies was uncommon and occurred with similar frequency in patients receiving posoleucel (7%) or placebo (5%). Three patients who received posoleucel were reported to have acute rejection per biopsy report by a central reader; none of these cases were assessed by the investigator as related to study drug.

The key secondary endpoint of the study was the change in BK viral load in patients receiving posoleucel versus those receiving placebo. The efficacy analysis excluded six patients in whom significant reductions in immunosuppression were made immediately prior to study entry. Posoleucel achieved greater viral load reductions versus placebo across all BK viral load measures. Antiviral responses among posoleucel patients increased over time, with maximal responses observed at Week 24. This clinically meaningful treatment effect was strongest among patients receiving posoleucel every two weeks and among those with high viral loads at study screening.

Clinical Development Plan

The topline data described above will inform next steps for this potential indication as well as our broader strategy in solid organ transplant patients.

Prevention of Multi-Virus Infection and Associated Disease in SOT Patients

Similar to HCT patients, the prevention of viral disease in SOT patients is important for both graft survival and the overall health and survival of patients. Published clinical guidelines recommend that all high and intermediate risk SOT patients, which account for nearly 90% of all SOT patients, should receive prophylactic therapy for CMV, which is only one of six viruses that posoleucel targets.

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There are currently no FDA- or EMA-approved antiviral therapies for prevention of multiple viral diseases or infections in SOT patients with one single therapy. Data from our ongoing multi-virus prevention study in allogeneic HCT patients and our Phase 2 study of kidney transplant patients with BK viremia will inform the potential for a POC study of posoleucel for multi-virus prevention in SOT patients.

Other Viruses Targeted by Posoleucel

Epstein-Barr Virus

Epstein-Barr virus is a latent herpesvirus that infects more than 90% of humans worldwide and establishes life-long latency after primary infection. During a primary infection, an immunocompetent host will mount vigorous CD4+ and CD8+ cellular immune responses and these T cells control both the primary infection and any periodic EBV reactivations. However, EBV reactivation can cause significant morbidity and mortality in immunocompromised patients and uncontrolled EBV reactivation can lead to fulminant viremia and progress to life-threatening post-transplantation lymphoproliferative disorder, or PTLD.

PTLD can occur at any age and after all types of transplants, though allogeneic HCT patients are at particular risk. The median time to development of EBV-associated PTLD, or EBV-PTLD, after HCT is two to four months. Fever and lymphadenopathy are the most common symptoms and signs of EBV-PTLD and, if not treated, PTLD generally progresses rapidly to multi-organ failure and death. Off-label rituximab has been used to treat EBV-PTLD. However, response to rituximab is not universal and mortality remains high in rituximab-refractory patients. In December 2022, tabelecleucel received marketing authorization in Europe to treat patients with relapsed or refractory EBV-PTLD who have received at least one prior therapy; the cell therapy has not been approved in other regions at this time.

In our CHARMS trial, two evaluable patients with EBV infections were treated with posoleucel; the overall response rate to EBV by six weeks post-infusion was 100%.

Human Herpesvirus Type 6

There are two variants of HHV-6: HHV-6A and HHV-6B, both infect and establish latency in different cell types including CD4+ T lymphocytes, monocytes, and other epithelial, fibroblastic and neuronal cells. No disease has been causally linked to HHV-6A, and its natural history is unknown. In contrast, HHV-6B primary infection is ubiquitous in the first two years of life, sometimes causing exanthema subitum (also known as roseola infantum and sixth disease). Subsequent viral latency gives the potential for reactivation and disease.

HHV-6 reactivation is the most frequent cause of encephalitis after HCT. Disease onset is typically two to six weeks post-transplant. Initial signs and symptoms include confusion, delirium, short-term memory loss, syndrome of inappropriate antidiuretic hormone secretion and seizures. Long-term outcomes can result in brain damage, memory defects and death. HHV-6 is also associated with delayed engraftment, allograft failure, acute GVHD and CMV reactivation. There are currently no FDA-approved treatments for HHV-6. The use of off-label antivirals is limited by several factors. Ganciclovir is associated with dose-limiting bone marrow toxicity which may delay HCT engraftment, cidofovir is associated with kidney toxicity and foscarnet is also associated with kidney toxicity, as well as the risks of infection and deep vein clots stemming from its required route of administration.

In our CHARMS trial, three evaluable patients with HHV-6 infections were treated with posoleucel; the overall response rate by six weeks post-infusion was 100% (3/3). One additional patient was found to have chromosomal integration of HHV-6 and was excluded from the efficacy analyses.

Posoleucel Commercial Opportunity

There is an urgent medical need for therapies to treat a large number of patients suffering from viral diseases who currently have limited or no treatment options. We are focused on the global development and commercialization of posoleucel as we see a large opportunity to serve patients suffering from devastating viral diseases and infections worldwide.
 

For our initial launch indications for the treatment and prevention of viral diseases in HCT patients, we believe approximately 30% of our annual addressable patient population is in the United States, 35% in the European Union, 5% in Japan, and 30% in 11 other target markets in the rest of the world. We project the addressable transplant patient population for posoleucel for the treatment and prevention of our target viral diseases will be approximately 41,000 HCT patients annually in 2025. There is significant unmet demand for HCT procedures as a result of the lack of access to matched or unmatched stem cell donors. By treating and preventing viral diseases, we believe that posoleucel can address this unmet medical need by enabling more patients to benefit from a curative haploidentical HCT procedure, which represents the fastest growing subset of the existing allogeneic HCTs.

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1—Posoleucel Treatment and Multi-Virus Prevention in Allogeneic HCT Patients

In 2019, approximately 38,000 allogeneic HCTs were performed in our target markets. We project this to grow by 3% annually to approximately 45,000 procedures per year by 2025 and estimate that approximately 41,000 allogeneic HCT patients will be eligible for posoleucel therapy for virus-associated HC, AdV and multi-virus prevention.
 

The observed incidence of virus-associated HC is 8-25% and 7-54% in pediatric and adult patients, respectively, and is higher after allogeneic HCT than after autologous HCT, particularly after haploidentical HCT with post-transplant exposure to cyclophosphamide as prophylaxis for GVHD. By 2025, we estimate there will be approximately 6,700 allogeneic HCT patients annually who develop virus-associated HC.
 

The incidence of AdV viremia is 32% among pediatric allogeneic HCT patients and 6% among adult allogeneic HCT patients. By 2025, we estimate there will be approximately 4,500 allogeneic HCT patients annually who develop AdV viremia.
 

Approximately 90% of all allogeneic HCT patients reactivate at least one of our six target viruses. By 2025, we estimate the addressable patient population for multi-virus prevention will be approximately 41,000 patients, inclusive of the addressable patient populations for virus-associated HC and AdV.
 

An analysis from the National Marrow Donor Program calculated that the demand for HCT procedures exceeded the number performed in the U.S. by approximately 290%. Lack of access to HLA matched or unmatched stem cell donors is a contributing factor to the unmet demand for allogeneic HCT. To broaden the pool of donors, researchers developed haploidentical transplants, in which a healthy first degree relative can often serve as a donor. Instead of a near-total HLA match, donors for a haploidentical transplant need to be only a 50% match to the patient. In addition to making it easier to find a suitable donor, haploidentical transplants can often be performed more promptly than traditional unrelated donor transplants. Importantly, this enables more patients to receive this curative treatment option for their underlying diseases faster. The successful outcome of haploidentical HCT is dependent on the use of T cell-replete conditioning strategies, which in turn leaves patients highly vulnerable to viral diseases and infections. By treating and preventing viral diseases and infections, we believe that posoleucel can accelerate the paradigm shift toward haploidentical HCT and enable more patients to benefit from this curative HCT procedure.
 

2—Posoleucel Treatment and Multi-Virus Prevention for Solid Organ Transplant Patients

We are developing posoleucel for the treatment of BK viremia in KT patients and for multi-virus prevention in SOT patients. Approximately 114,000 SOTs were performed in 2020 in our target markets, of which 72,000 were KTs. We project this to grow by 2% annually to 126,000 SOTs by 2025, of which almost 80,000 are for KT, and we estimate that approximately 110,000 KT and SOT patients will be eligible for posoleucel therapy for BK viremia and multi-virus prevention.
 

BK viremia is detected in up to 20% of KT patients and up to 50% of patients with BK viremia will progress to BK nephropathy, resulting in decreased graft function and graft survival. We estimate that there will be more than 14,000 KT patients annually who will develop BK viremia and can benefit from posoleucel therapy.
 

Published clinical guidelines recommend that all high-risk (seropositive donor/seronegative recipient, or D+/R-) SOT patients and intermediate risk (D+/R+ and D-/R+) SOT patients should receive prophylaxis for CMV, which is just one of the six viruses posoleucel targets. High-risk patients represent approximately 18% of SOT patients and intermediate risk patients approximately 69%. By 2025, we estimate the addressable patient population for multi-virus prevention in all SOT will be approximately 110,000 patients, inclusive of the addressable patient populations for BK viremia.

3—Posoleucel for Other Viruses Associated with Transplant and Immunocompromised Patients

We believe posoleucel can also address high unmet medical need in transplant patients with viral diseases associated with EBV, HHV-6, and JC viruses. EBV-PTLD is a severe complication after allogeneic HCT. PTLD was diagnosed in 4% of HCT patients. There are currently no FDA-approved therapies for patients with EBV-PTLD. Over 90% of individuals are infected with HHV-6 before the age of two. In over half of allogeneic HCT patients, HHV-6 is reactivated resulting in clinical manifestations such as encephalitis, delayed engraftment and an increased rate of GVHD leading to increased mortality. Up to 80% of the general population is seropositive for JCV. Rates of PML, the primary disease caused by JC virus, are elevated in HCT patients. The median survival time for HCT patients

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with PML is less than two years.
 

We believe transplant patients represent only one segment of the large number of patients suffering from devastating viral infections who could potentially benefit from posoleucel. Other individuals with weakened immune systems, including those with primary immunodeficiencies, the elderly and very young and patients who have compromised immune systems due to cancer or the treatment of their cancer are all at high risk of the life-threatening consequences of viral diseases and infections. Each of these target patient populations represents a large potential market that is currently untapped or underserved by existing therapies.

Our Commercialization Plan

If approved, we intend to commercialize our highly innovative off-the-shelf VST therapies globally to serve a large number of patients suffering from the life-threatening consequences of viral diseases. Initially, to launch our late clinical stage therapies for the treatment of transplant patients, we will establish a focused commercial infrastructure targeting high-volume transplant centers globally. Based on the relatively small number of transplant centers that perform the majority of these transplant procedures, we believe that the entire target market for our VST therapies could be served by a small global team. In the US, there are approximately 185 stem cell transplant centers, of which the top 70 centers perform 80% of the allogeneic HCT, and in the five major European countries (Germany, France, UK, Italy, Spain) there are approximately 410 stem cell transplant centers, of which the top 129 centers perform 80% of allogeneic HCT. Furthermore, in the U.S. there are approximately 240 centers performing kidney transplants, of which the top 100 centers perform 80% of the transplants. We believe that many of these same transplant centers will also have participated in our pivotal and proof-of-concept trials for posoleucel and ALVR106 and will have significant experience with our investigational VSTs, which will support commercial launch and adoption of our therapies. As we eventually progress to serve non-transplant patients at high-risk for the life-threatening consequences of viral diseases, we will expand our global commercial capabilities.

Our team has extensive experience launching and commercializing specialty pharmaceuticals globally with a strong track record of achieving broad patient access resulting in industry leading product launches. By targeting severe viral diseases that result in prolonged hospitalization, multi-organ disease and failure and increased risk of death, and currently have limited or no treatment options, we believe that our therapies have the potential to transform the lives and care of patients globally.

Transplant-Related Viral Diseases Cause Significant Burden to the Healthcare System

Along with increased morbidity and mortality, viral diseases and infections in allogeneic HCT patients have a significant impact on healthcare costs. We conducted a real-world claims analysis to assess the economic burden, health resource utilization, and clinical outcomes between allogeneic HCT patients with virus-associated hemorrhagic cystitis and those without virus-associated HC. The study population included 13,363 patients with a first (index) allogeneic HCT procedure between January 1, 2012 and December 31, 2017 from the Decision Resources Group Real World Evidence Data Repository. As shown in the figure below, HCT patients with virus-associated HC incur significantly greater healthcare reimbursement costs (p<0.0001) in the 1-year post allogeneic HCT. After adjusting for baseline characteristics, follow-up duration and number of comorbidities, mean reimbursement costs were approximately $200,000 higher for allogeneic HCT patients with virus-associated HC versus allogeneic HCT patients without virus-associated HC, regardless of

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whether patients had GHVD. Patients with virus-associated HC had higher length of stay (LOS) for the index hospitalization (p<0.0001), higher readmission rate (p<0.0001) and higher number of days in the hospital after the index hospitalization (p<0.0001).

Figure 17. Real-world claims analysis confirms high economic burden of virus-associated HC and multiple viral infections

Separately, this claims analysis also showed that allogeneic HCT patients with an increasing number of double-stranded DNA viral infections (BKV, CMV, AdV, EBV and HHV-6) have a significantly higher burden of reimbursements and healthcare resource utilization and poorer patient outcomes within one year of undergoing allogeneic HCT. Adjusted mean reimbursement costs were $198,000 for patients with no viral infection, $314,000 for patients with one viral infection, $426,000 for two viral infections, and $571,000 for three or more viral infections in patients without GVHD. In patients with GVHD, the reimbursement costs were higher and similarly increased substantially with each additional infection, with patients with 3 or more infections incurring $843,000 in reimbursed costs. Our results are consistent with those previously published on the high economic burden of transplant-related viral infections.

ALVR106 and ALVR109 VST Therapy for Respiratory Viruses

Acute respiratory tract infections due to respiratory viruses including RSV, influenza, PIV, hMPV and coronaviruses such as SARS-CoV-2, the virus that causes COVID-19, are a major public health problem. For example, RSV-induced bronchiolitis is the most common reason for hospital admission in children less than one year of age. The lack of approved antiviral agents to treat many respiratory viruses underscores the need for alternative treatment and prevention strategies.

We have two VST therapy candidates to target devastating respiratory viruses: ALVR106, an allogeneic off-the-shelf multi-virus-specific T-cell therapy for RSV, influenza, PIV, and hMPV, and ALVR109, an allogeneic, off-the-shelf VST therapy for SARS-CoV-2. We also amended our then-existing sponsored research agreement with BCM, which we refer to as the BCM SRA, to support their work on the initial discovery and development of allogeneic, off-the-shelf, virus specific T-cell therapies to combat SARS-CoV-2.

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ALVR106: VST Therapy for the Treatment of Patients with Respiratory Viruses

We are developing ALVR106 as an allogeneic, off-the-shelf VST therapy designed to treat or prevent four common respiratory viruses, RSV, influenza, PIV, and hMPV. A Phase 1/2 POC clinical trial of ALVR106 to target severe respiratory diseases in high-risk populations is ongoing.

Figure 18. Consequences to high-risk patients with respiratory virus infections

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Pre-Clinical Data

As illustrated below, our preclinical in vitro data demonstrates that ALVR106 can be reproducibly generated from healthy seropositive donors and reactive cells have potent antiviral activity against each of the target viruses. Additionally, these cells do not target non-virus-infected autologous or allogeneic cells. We believe this data supports the potential for antiviral benefit and safety of ALVR106 when administered to patients.

Figure 19. ALVR106 has selective antiviral activity against target viruses, leaving non-virus infected targets intact

Respiratory Virus Infections in HCT Patients

Respiratory tract infections due to RSV, influenza, PIV and hMPV, are detected in up to 40% of allogeneic HCT patients. In approximately half of these patients, these viral infections progress from less serious upper respiratory tract infections, with symptoms similar to those of a common cold, to far more serious lower respiratory tract infections, with severe symptoms including pneumonia and bronchiolitis. These more serious infections are associated with mortality rates between 20-45%.

RSV

RSV is a common infectious complication of transplantation, with an incidence of up to 12% in HCT patients. In immunocompetent adults, infections from RSV typically result in upper respiratory tract infections characterized by cough, fever and runny nose. However, in approximately two-thirds of infected HCT patients, an RSV infection develops into a lower respiratory tract infection characterized by severe symptoms including pneumonia and bronchiolitis. These infections are associated with morbidity and mortality rates of up to 28%. Therapy for RSV infections in HCT patients consists primarily of supportive care. Aerosolized ribavirin, or RBV, is FDA-approved for the treatment of RSV but is logistically difficult to administer, as it requires a specialized nebulization device that connects to an aerosol tent surrounding the patient.

Influenza

Influenza infections have been found in up to 46% of allogeneic HCT patients. Approximately 20% of HCT patients with influenza infections progress to develop pneumonia which has been associated with a 30-day mortality rate of 28%. Influenza infections are a major cause of morbidity and mortality in individuals who have weakened immune systems, the elderly and patients with chronic diseases. While there are preventative vaccines for influenza, they are only partially effective in HCT patients. Available antiviral drugs are associated with the development of drug resistance at high rates in HCT patients.

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PIV

PIV primarily affects young children and can cause upper respiratory tract infections and lower respiratory tract infections including conditions such as the common cold, croup, bronchitis, bronchiolitis and pneumonia. In immunocompetent individuals the course of these infections is limited due to antiviral responses from both the innate and adaptive immune systems. Up to 18% of immunocompromised HCT patients develop PIV infections, which can lead to decreased lung function, multiorgan failure and graft loss. Mortality rates of HCT patients with PIV infections can be as high as 60%. There are currently no FDA- or EMA-approved vaccines or treatments for PIV infections.

hMPV

Between 5-9% of HCT patients develop hMPV infections. hMPV is a ubiquitous virus to which nearly the entire population globally has been exposed by age five. In the majority of cases, hMPV results in upper respiratory infections with symptoms similar to that of the common cold. In 21-40% of hMPV infections in HCT patients, however, the viral infection progresses from a mild upper respiratory disease to a serious lower respiratory disease that is associated with fatality rates of up to 80%. There are currently no FDA- or EMA-approved therapies or vaccines for hMPV.

Clinical Development Plan

A Phase 1/2 clinical trial of posoleucel in autologous and allogeneic HCT patients with respiratory viral diseases is enrolling patients in the U.S. This POC trial is a Phase 1/2, double-blind, placebo-controlled, dose escalation and expansion trial of ALVR106 in addition to standard of care to assess safety and efficacy of ALVR106.

Figure 20. AVLR106 Phase 1/2 POC trial design

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Respiratory Virus Infections in High-risk Populations: Elderly, Young, Cancer Patients

In developed countries, there are well-defined high-risk populations in whom RSV infection is more likely to progress into a severe lower respiratory tract infection, including infants less than three months of age or born prematurely, the elderly and immunosuppressed patients. In children, bronchiolitis and pneumonia are the most common clinical manifestations. RSV is responsible for between approximately 66,000 and 199,000 deaths each year. In adults, RSV infections develop annually in 3-7% of elderly individuals and in 4-10% of high-risk adults, where they can cause pneumonia and bronchitis and may lead to death. Importantly, previous infection does not confer immunity. To date, there is no FDA- or EMA-approved vaccine and no clear evidence that treatment with antiviral agents or anti-inflammatory agents reduces the length of infection or the duration of hospital stay in any population. A neutralizing monoclonal antibody, palivizumab, has been developed as immunoprophylaxis to prevent RSV infection; however, its use is limited to high-risk infants because evidence of its effectiveness is limited in broader patient populations.

Influenza

Influenza virus infection causes substantial morbidity and mortality. The World Health Organization, or WHO, estimates that annual epidemics cause 3-5 million cases of severe illness worldwide, and influenza-associated respiratory deaths are estimated to be between approximately 290,000 and 650,000 persons annually. Of these, the highest mortality rates are observed in people aged 75 years and older (51.3 to 99.4 individuals per 100,000). The overall rate of respiratory-associated deaths is also relatively high in patients less than five years of age (2.1 to 23.8 per 100,000). These events occur despite the availability of vaccines and antiviral therapies for influenza. A recent study in the United States demonstrated that vaccination was only 38% effective for influenza A or B viral infections. In the event of infection, patients may be treated with neuraminidase inhibitors, such as oseltamivir and zanamivir. However, not only must these antivirals be administered early in the disease course, they may induce resistance to the influenza virus.

PIV

PIV is among the most common respiratory tract infection worldwide and is associated with both upper and lower respiratory tract infections in both children and adults. Progression from upper to lower respiratory tract infection is most common in children less than five years old and in immunocompromised adults, including the elderly and those with hematologic malignancies. In children, seasonal epidemics account for 40% of hospitalizations for lower respiratory tract illness and 75% of croup cases. Overall, 7% of pediatric hospitalizations for febrile respiratory illness in children less than 5 years old are due to PIV. The estimated annual cost of pediatric hospitalization and emergency room visits due to PIV is greater than $200 million, according to a 2016 study. PIV accounts for 15% of respiratory illness in adults and most commonly manifests as upper respiratory tract infections or pneumonia. Approximately 2.0-11.5% of adult hospitalizations for respiratory illnesses are due to PIV. Currently there are no FDA- or EMA-approved vaccines or antiviral therapies for PIV, and treatment of infection consists of supportive care.

hMPV

Similar to other respiratory pathogens, hMPV causes both upper and lower respiratory tract infections with the most severe disease observed in infants, young children, the elderly, and immunocompromised patients. The most common diagnoses associated with hMPV are bronchiolitis and pneumonia. Studies in children either in the hospital or seen in the outpatient setting show that hMPV is associated with between 6% and 40% of acute respiratory illness. Similar to other respiratory viruses, exposure does not confer immunity, and despite almost all people having been infected with hMPV by age five, re-infection occurs throughout adulthood and is associated with morbidity and mortality in the elderly population. In one study, 46% of hMPV cases were seen in patients greater than 65 years of age and 60% of these patients were hospitalized. In a separate study in an elderly care center, 50% of infected patients developed bronchitis or pneumonia, which led to 50% mortality. Currently there are no FDA- or EMA-approved vaccines or antiviral therapies for hMPV, and treatment of infection consists of supportive care.

Clinical Development Plan

We also plan to test ALVR106 in high-risk patient populations outside of the transplant setting.

Commercial Opportunity

ALVR106 is an allogeneic, off-the-shelf VST therapy candidate designed to target four common respiratory viruses that represent important causes of morbidity and mortality in HCT and SOT patients, as well as other high-risk patient populations.

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ALVR106 for Transplant Patients

In HCT patients, respiratory viral infections occur in both allogeneic HCT and autologous HCT patients. Respiratory viruses infect patients both within the first year post-transplant and beyond. Our target population for ALVR106 includes patients who have undergone allogeneic and autologous HCTs and who have lower respiratory tract infections and upper respiratory tract infections at medium or high risk of progressing to lower respiratory tract infections.

We project the number of allogeneic and autologous HCT procedures to grow 3% annually to approximately 42,000 and 51,000 procedures annually, respectively, by 2025 in our target markets in North America, Europe, Asia Pacific and Latin America. By 2025, we estimate there will be nearly 16,000 HCT patients annually infected with one of the four respiratory viruses targeted by ALVR106. We believe that ALVR106 will be effective for treating infections in HCT patients with one or more of the targeted respiratory viruses.

Respiratory viruses can infect patients of all types of SOTs, although the majority of the literature describes devastating consequences in lung transplant patients. Our initial target population will include lung transplant patients hospitalized for respiratory viruses.

We project the number of new lung transplants to grow 2% annually to approximately 7,000 new lung transplants annually by 2025 in our target markets. We estimate the size of the prevalent lung transplant population to be nearly 56,000 patients in our target markets. By 2025, we estimate that there are annually over 12,000 lung transplant patients that are infected with one of the four respiratory viruses targeted by ALVR106.

ALVR106 for High-risk Populations: Elderly, Young, Cancer Patients

We believe transplant patients represent only a small fraction of the large number of patients suffering from devastating respiratory infections who could potentially benefit from ALVR106. Other individuals with weakened immune systems, including those with primary immunodeficiencies, the elderly and very young and patients who have compromised immune systems due to cancer or the treatment of their cancer are all at high risk of the severe consequences of respiratory infections. Each of these target patient populations represents a large potential market that is currently untapped or underserved by existing therapies.

ALVR109: VST Therapy for the Treatment of Patients with COVID-19

COVID-19

SARS-CoV-2 infection causes the severe and life-threatening viral disease, COVID-19. COVID-19 has become synonymous with profound depletion of endogenous T cells, or lymphopenia, resulting in a state of acute immune deficiency, rendering infected individuals susceptible to developing overwhelming and sometimes fatal pneumonia. Beyond the lungs, COVID-19 is a multi-organ disease that affects the heart, kidneys, brain, liver and gastrointestinal tract, as well as causing blood clots.

Studies to date estimate that the risk of mortality is up to 500% higher in patients 65 years of age or greater than in those aged 30 to 59 years. In addition, other risk factors for severe COVID-19 include chronic lung or heart disease, hypertension, diabetes and underlying immune compromise. Accordingly, there is an urgent need to rapidly develop an effective therapy for COVID-19.

T cells are known to play a critical role in controlling viral infections, including respiratory infections caused by SARS-CoV, the coronavirus with the highest known homology to SARS-CoV-2. Greater than 80% of hospitalized patients with COVID-19 are lymphopenic, with reduced CD8+ and CD4+ T-cell counts. These reductions in T-cell counts correlate negatively with survival. Reduced T-cell counts have been observed to be prevalent in older COVID-19 patients and those with severe illness, regardless of age. As further data on the immunogenicity of SARS-CoV-2 continue to emerge, the important protective role of SARS-CoV-2-specific T cells is increasingly being recognized.

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ALVR109

ALVR109 is a SARS-CoV-2-specific T-cell product candidate comprised of polyclonal (CD4+ and CD8+) VSTs that is generated from healthy, eligible seropositive donors and targets immunogenic viral antigens. As illustrated below, preclinical in vitro data developed pursuant to the BCM SRA indicated that ALVR109 demonstrated selective cytolytic activity against target cells presenting SARS-CoV-2 antigens while leaving non-virus infected targets intact. Preclinical data presented at IDWeek 2021 demonstrate that ALVR109 provides antiviral activity and coverage against multiple SARS-CoV-2 variant strains.

Figure 21. ALVR109 has demonstrated selective cytolytic activity against SARS-CoV-2 while leaving non-virus infected targets intact

In recent publication, ALVR109 was well-tolerated and was associated with clinical improvement in four transplant and non-transplant patients, with cells that expanded and persisted post-infusion. Positive reports of ALVR109 compassionate use in immune-compromised patients also have been published and presented, including presentations at the 2022 American Transplant Congress, providing important insight into the potential utility of a virus-specific T cell approach to treating respiratory viruses in immunocompromised patients.
 

The development of ALVR109 demonstrates our ability to rapidly and efficiently develop new VST therapy candidates in response to emerging viral pathogens. Our approach of delivering high-risk patients with banks of ex vivo-expanded, VST therapies generated from healthy immune donors is designed to address the underlying immune deficiency. Furthermore, VST therapies are prospectively prepared and thus immediately available as an off-the-shelf therapy. These VST therapies are polyclonal and target multiple virus-expressed antigens, which we believe makes them less susceptible to viral point mutations that typically confer drug resistance. We believe these features distinguish our approach from others currently in development.

Clinical Development Plan

We are monitoring the evolution of the SARS-CoV-2 virus and the COVID-19 pandemic to guide the next steps for this program in the context of our broader R&D portfolio and priorities.

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ALVR107: VST Therapy for the Treatment of Hepatitis B Virus

Hepatitis B Virus

The global prevalence of HBV has been estimated to be between 292 and 360 million people with approximately 260 million people living with chronic HBV infection. HBV is most common in the Western Pacific and African regions, where approximately 6% of the adult population is infected. In contrast, only approximately 1.6% and 0.7% of the European and Americas regions, respectively, are infected. About 30% of patients with chronic HBV develop liver cirrhosis, and nearly 23% of these die within five years of developing cirrhosis.

Current treatment options for chronic HBV consist of life-long antiviral therapy to suppress virus replication. This can slow the progression of liver cirrhosis and reduce the incidence of liver cancer. However, there are no curative therapies available.

Chronic HBV infection is associated not only with significant morbidity and mortality as noted above, but also with weak or absent endogenous HBV-specific T-cell reactivity. In contrast, clinical recovery and effective antiviral therapy are associated with sustained viral control by HBV-specific T cells. Therefore, an off-the-shelf VST therapy that could cure HBV would meet a critical unmet medical need.

POC for the potential of adoptive T cell therapy to achieve functional HBV cure has already been established. A Taiwanese study published in Blood in 2005 demonstrated that 65% of chronic hepatitis B patients who underwent allogeneic HCT transplantation and received cells from a donor with natural HBV immunity, achieved functional HBV cure post-transplant.

ALVR107

ALVR107 is an allogeneic, off-the-shelf VST therapy designed to cure patients with HBV. ALVR107 is comprised of a bank of VSTs manufactured from eligible third-party healthy donors who are pre-screened for infectious agents and disease risk factors. These donors are chosen to reflect and accommodate the HLA diversity of the patient population.

Clinical Development Plan

Preclinical and IND-enabling studies of ALVR107 to treat and cure HBV were completed in 2022 to support advancement into a POC study. The company expects to initiate clinical development of ALVR107 after completion of the posoleucel Phase 3 registrational studies.

Competition

The biopharmaceutical industry is characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. While we believe that our innovative and proprietary technology, the expertise of our executive and scientific team, and our access to cell therapy process development and manufacturing expertise at ElevateBio and BaseCamp provide us with competitive advantages, we face potential competition from many different sources, including pharmaceutical and biotechnology companies, academic institutions and public and private research institutions. VST therapies that we successfully develop and intend to commercialize may compete with existing therapies and new therapies that may become available in the future.

Many of our competitors, either alone or with their collaborators, may have a more established presence in the market and significantly greater financial, technical and human resources than we have. The competitors also compete with us in recruiting and retaining qualified scientific, sales, marketing and management personnel. Smaller or early-stage companies may also prove to be significant competitors through collaborative arrangements with large and established companies.

Our commercial potential could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, or are less expensive than any products that we may develop. Our competitors may also obtain FDA or other regulatory approval for their products faster than we may obtain approval for ours, which could result in our competitors establishing a strong market position before we are able to enter the market or make our development more complicated.

If approved, our VST therapies would compete with cell therapies and antivirals used to treat and prevent the viral diseases our VST therapies target.

Cell Therapies

There are currently no FDA-approved cell therapies for treating or preventing the viral diseases and infections we are targeting. Atara Biotherapeutics, Inc.’s Ebvallo™ (tabelecleucel), an off-the-shelf, allogeneic T-cell immunotherapy, for HCT and SOT patients with EBV+PTLD (EBV-associated post-transplant lymphoproliferative disease), received European marketing authorization in December 2022.

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Antivirals

There are currently no FDA or EMA-approved antiviral therapies for treating most viral diseases and infections in the post-transplant setting, and current antiviral therapies are associated with significant toxicity, including renal insufficiency and bone marrow suppression. Despite the availability of antivirals for some of the viral diseases we are targeting, patients continue to experience high levels of morbidity and mortality. Additionally, the effectiveness of these antivirals is limited due to the emergence of drug resistance. Similarly, there are limitations to prophylactic approaches, such as vaccines, which may not work well in immunosuppressed patients, the elderly, and the very young who are unable to mount an effective immune response. The antiviral therapies currently available for the indications we are targeting with our allogeneic, off-the-shelf VST therapy candidates are listed below. Unless otherwise noted, there are no antiviral therapies approved by the FDA for the treatment or prevention of the viral diseases we are targeting:

Posoleucel: With the exception of valganciclovir, ganciclovir and letermovir for the prevention of CMV disease, and maribavir for the treatment of refractory CMV infection/disease, there are no products FDA-approved for the treatment of AdV, EBV, BKV, HHV-6, or CMV infections or their consequent diseases in allogeneic HCT or SOT patients. Furthermore, there are currently no FDA- or EMA-approved antiviral therapies for the prevention of multiple-viral diseases or infections in transplant patients. Cidofovir is sometimes used off-label for the treatment of BKV-associated HC and AdV infections in HCT patients. Additionally, Vera Therapeutics has completed a Phase 2 clinical trial for MAU868 for the treatment of BKV in KT patients and is exploring the development of MAU868 for the treatment of BKV cystitis in HCT recipients. Memo Therapeutics’ MTX-005, a therapeutic antibody candidate, is in Phase 1 development for the treatment of BKV infection in renal transplant patients. Helocyte, Inc. is conducting Phase 2 clinical trials of its Triplex vaccine to control CMV infections in HCT patients. Rituximab, an approved antiviral treatment for rheumatoid arthritis and B-cell non-Hodgkin’s lymphoma, is used off-label for the treatment of EBV infections in HCT and SOT patients. Brincidofovir, a lipid conjugate of cidofovir, is in early development by SymBio Pharmaceuticals for the treatment of adenoviral disease after allogeneic HCT. AiCuris has in early development AIC468 to prevent BK viral infection in transplanted kidneys. Finally, intravenous immunoglobulin (IVIG) has been explored for the prevention and treatment of BKV associated nephropathy in renal transplant patients, but not in HCT patients. Even in renal transplant patients, there is limited efficacy data for IVIG to support routine use.

ALVR106: The FDA has approved ribavirin (aerosol) to treat RSV infections in children and pavilizumab to treat RSV infections in children younger than two years old. Ribavirin is also used off-label for the treatment or prevention of RSV infections in HCT and SOT patients and PIV infections and hMPV infections in HCT patients. AstraZeneca is conducting a Phase 2 clinical study of nirsevimab to treat RSV infections in immunocompromised children. Certain approved antiviral medications, including oseltamivir, zanamivir, baloxavir and peramivir, are used to treat influenza infections in HCT and SOT patients. Ansun BioPharma, or Ansun, is conducting Phase 2 clinical trials of DAS181 to treat influenza infections. Several vaccines are FDA-approved and in clinical development for the prevention of influenza infections. Ansun is also conducting Phase 3 clinical studies of DAS181 to treat PIV infections in immunocompromised patients.

ALVR107: There are numerous antiviral therapies approved by the FDA and in clinical development for the treatment of chronic HBV infections. However, these current treatment options for chronic HBV consist of life-long antiviral therapy to suppress virus replication. This can slow the progression of liver cirrhosis and reduce the incidence of liver cancer, but there are no curative therapies available.

Intellectual Property

Our intellectual property is critical to our business and we strive to protect it, including by obtaining, maintaining, defending, and enforcing patent protection in the United States and internationally for our proprietary technology, improvements, platforms, product candidates and components thereof, novel biological discoveries, new therapeutic approaches and potential indications, and other inventions that are important to our business. For our product candidates, generally we initially pursue patent protection covering compositions of matter, methods of production, and methods of use. Throughout the development of our product candidates, we will seek to identify additional means of obtaining patent protection that would potentially enhance commercial success, including through additional pharmaceutical formulations, methods of use and production.

As of January 18, 2023, our patent portfolio includes ten patent families exclusively in-licensed from Baylor College of Medicine, or BCM, in our field (one of which is co-owned by AlloVir). These families include issued and pending patents related generally to our allogeneic, off-the-shelf, single and multi-VST cell therapies, our clinical product candidates posoleucel, ALVR106 and ALVR109, various pre-clinical product candidates including ALVR107 and ALVR108, and our current clinical and backup processes for generating VST-cell products and banks. Specifically, we exclusively in-license at least four issued U.S. patents, 54 patents issued in foreign jurisdictions, and 80 patent applications pending worldwide. Our issued patents are expected to expire between 2030 and 2033, and any patents that may issue from our pending patent applications are expected to expire between 2030 and 2042, absent any patent term adjustments or extensions. As to the patent term extension to restore patent term lost during product development and the FDA regulatory review process, the restoration period cannot be longer than five years and the total patent term including the restoration period must not exceed 14 years following FDA approval.

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Our portfolio related to our posoleucel product candidate includes two patent families directed to multi-VST compositions and methods of making and using such compositions therapeutically. The first family includes two issued U.S. patents with claims directed to our clinical and backup methods of making multi-VST cell lines and related patent applications are pending in the U.S. and Europe. Patents in this family are expected to expire in 2030, absent any patent term adjustments or extensions. The second family includes one issued U.S. patent with claims directed to methods of making posoleucel, one issued European patent with claims directed to methods of making multi-VST compositions including posoleucel and ALVR106, and a second issued European patent with claims directed to compositions of multi-VST compositions including posoleucel and ALVR106, made via such methods. The first European patent is validated in 19 European states, and the second in 21 European States, each including Denmark, France, Germany, Spain and the UK. Related patent applications are pending in the U.S. and in Europe. Patents in this family are expected to expire in 2033, absent any patent term adjustments or extensions as noted above.

Our portfolio related to our ALVR106 product candidate includes the two patent families discussed above with respect to posoleucel as well as a patent family directed to the ALVR106 product and methods of making and using the same therapeutically. This patent family includes one U.S. pending patent application and 14 pending patent applications in foreign jurisdictions including Australia, Canada, China, Europe, and Japan. Any patents that may issue from this patent application are expected to expire in 2040, absent any patent term adjustments or extensions.

Our portfolio licensed from BCM also includes a patent family related to our ALVR109 product candidate and methods of treating COVID-19 and other coronavirus infections using the same. This patent family includes one U.S. pending patent application, and 4 pending patent applications in foreign jurisdictions including Canada, Europe, Japan, and Taiwan. Any patents that may issue from the patent applications in this family are expected to expire in 2041, absent any patent term adjustments or extensions.

Our portfolio licensed from BCM also includes two pending U.S. provisional patent applications, one pending PCT application, and one pending application in Taiwan related to VST compositions, including our ALVR107 and ALVR108 product candidates, and methods of making and using the same therapeutically. Any patents that may issue from the patent applications in this family are expected to expire in 2042, absent any patent term adjustments or extensions.

Our portfolio further includes other patent families related to our VST technologies. For example, our portfolio includes one patent family with one U.S. pending patent application and 15 pending patent applications in foreign jurisdictions including Australia, Canada, China, Europe, and Japan, and relates to our process of selecting donors for VST generation and our methods of matching patients with suitable VST-cell lines; one patent family with one pending U.S. application and 13 pending applications in foreign jurisdictions including Australia, Canada, China, Europe, and Japan, and relates to methods for the prophylactic treatment of viral infections; one patent family with one issued U.S. patent, three issued foreign patents, and pending patent applications in the U.S. and foreign jurisdictions including Australia, Canada, China, Europe, and Japan, and is directed to methods of identifying peptides that are likely to be immunogenic; one patent family including one pending PCT application and pending applications in foreign jurisdictions directed to universal antigen-specific T cells compositions and methods of making and using the same; and one patent family including 11 issued patents (including a European patent validated in 7 European states) and 3 pending patent applications with claims directed to methods of rapidly expanding T-cells. Patents in the T-cell expansion family are expected to expire in 2032, and any patents that may issue from the immunogenicity family, the donor selection family, the methods for prophylactic treatment family, or the universal antigen-specific T cell family are expected to expire in 2036, 2040, 2040, and 2041, respectively, absent any patent term adjustments or extensions.
 

Individual patents extend for varying periods depending on the date of filing of the patent application or the date of patent issuance and the legal term of patents in the countries in which they are obtained. Generally, patents issued for regularly filed applications in the United States are granted a term of 20 years from the earliest effective non-provisional filing date. In addition, in certain instances, a patent term can be extended to recapture a portion of the U.S. Patent and Trademark Office, or the USPTO, delay in issuing the patent as well as a portion of the term effectively lost as a result of the FDA regulatory review period. However, as noted, as to the FDA component, the restoration period cannot be longer than five years and the total patent term including the restoration period must not exceed 14 years following FDA approval.

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We also rely on trade secrets relating to product candidates and seek to protect and maintain the confidentiality of proprietary information to protect aspects of our business that are not amenable to, or that we do not consider appropriate for, patent protection. It is our policy to require our employees, consultants, outside scientific partners, sponsored researchers and other advisors to execute confidentiality agreements upon the commencement of employment or consulting relationships with us. These agreements provide that all confidential information concerning our business or financial affairs developed or made known to the individual during the course of the individual’s relationship with us is to be kept confidential and not disclosed to third parties except in specific circumstances. Our agreements with employees and consultants also provide that all inventions conceived by the employee or consultant in the course of employment or consulting relationships with us or from the employee’s or consultant’s use of our confidential information are our exclusive property and require such employees and consultants to assign their title, right and interest in such inventions to us. Although we take steps to protect our proprietary information and trade secrets, including through such contractual means with our employees and consultants, third parties may independently develop substantially equivalent proprietary information and techniques or otherwise gain access to our trade secrets, including through breaches of such agreements with our employees and consultants. Thus, we may not be able to meaningfully protect our trade secrets.

Sponsored Research, Collaboration, License and Other Agreements

Amended and Restated Exclusive License Agreement with BCM

In June 2017, we signed a License Agreement, or the License Agreement, with BCM, whereby we acquired a royalty-bearing, worldwide, exclusive license to BCM’s rights in Subject Technology and related patent rights in the field of viral infection. In May 2020, we entered into an amended and restated exclusive license agreement, or the A&R License Agreement, with BCM, pursuant to which we obtained (a) an exclusive worldwide license, with the right to sublicense, under certain patent rights and other intellectual property rights of BCM, to make, have made, use, market, sell, offer to sell, lease, import and export products in a particular field, except that such license is non-exclusive within a particular subfield, and in addition with respect to certain patent rights such license is limited to two particular subfields, and (b) an exclusive, worldwide sublicense, with the right to further sublicense, under all patent rights and other intellectual property rights that are exclusively licensed to BCM by a certain third party licensor, to make, have made, use, market, sell, offer to sell, lease, import and export products in the same field. Our rights are subject to the rights of the U.S. government and certain rights retained by BCM.

Unless earlier terminated, the A&R License Agreement will expire on a country-by-country basis with respect to a product upon the later of (a) the expiration of the last to expire valid claim of a patent or patent application covering such product in such country or (b) 10 years after the first commercial sale of such product in such country. We may terminate the A&R License Agreement in its entirety at any time for convenience upon a certain number of days’ written notice. BCM may terminate the A&R License Agreement in its entirety for our uncured material default.

BCM maintains control of all filing, prosecution and maintenance of its patent rights licensed by us, and we are responsible for all related costs and expenses during the term of the agreement. We also reimbursed BCM for costs and expenses (including reasonable legal fees and expenses) incurred prior to the effective date of the agreement with respect to the filing, prosecution and maintenance of the patent rights licensed by us. If BCM licenses the patent rights licensed by us to third parties for additional fields of use, our responsibility for patent-related costs and expenses will be reduced on a pro-rata basis.

Under the A&R License Agreement, we must use commercially reasonable efforts to develop and commercialize one or more products in certain countries. As partial consideration for the rights conveyed by BCM under the original agreement executed in June 2017, we paid BCM a non-refundable license fee of $250,000. During the term of the A&R License Agreement, we are obligated to pay BCM a non-refundable annual license maintenance fee of $20,000 on the first through fourth anniversaries of the original agreement date and $40,000 beginning on the fifth anniversary of the original agreement date, but beginning with the fifth anniversary of the original agreement date, license maintenance fees are fully creditable against royalty revenue due in the applicable year. We are required to pay certain milestone payments upon the achievement of specified clinical, regulatory, and sales milestones. In the event that we are able to successfully develop, launch and commercialize a product under the A&R License Agreement, total milestone payments could exceed $40.0 million. BCM is also eligible to receive tiered royalties at percentage rates ranging from less than 1% to the low single-digits, on net sales of any products that are commercialized by us or our sublicensees that incorporate, utilize or are made with the use of, the intellectual property licensed by us. To the extent we sublicense our license rights under the A&R License Agreement, BCM would be eligible to receive tiered sublicense income at percentage rates in the mid-single to low double-digits.

In November 2020, we entered into the First Amendment, or the License Amendment, to the A&R License Agreement. Under the License Amendment, we assumed responsibility from BCM for the filing, prosecution and maintenance of the patent rights licensed by us from BCM under the A&R License Agreement that are in common with the License Agreement. Further, BCM also transferred to us the right of enforcement against third parties for any suspected infringement of any claims in such patent rights or misuse, misappropriation, theft or breach of confidence of other proprietary rights.

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Exclusive License Agreement with BCM

In November 2020, we signed a second License Agreement, or the Second License Agreement, with BCM, whereby we acquired a royalty-bearing, worldwide, exclusive license to BCM’s rights in Subject Technology and related patent rights outside the field of viral infection (all fields other than those covered by the License Agreement Amendment noted above).

Unless earlier terminated, the Second License Agreement will expire on a country-by-country basis with respect to a product upon the later of (a) the expiration of the last to expire valid claim of a patent or patent application covering such product in such country or (b) 10 years after the first commercial sale of such product in such country, provided that the Second License Agreement shall not expire later than March 25, 2040. We may terminate the Second License Agreement in its entirety at any time for convenience upon a certain number of days’ written notice. BCM may terminate the Second License Agreement in its entirety for our uncured material default.

Under the Second License Agreement, BCM transferred to us control of all filing, prosecution and maintenance of the patent rights licensed by us, and we are responsible for all related costs and expenses during the term of the Second License Agreement. BCM also transferred to us the right of enforcement against third parties for any suspected infringement of any claims in the patent rights or misuse, misappropriation, theft or breach of confidence of other proprietary rights. We also reimbursed BCM for costs and expenses (including reasonable legal fees and expenses) incurred prior to the effective date of the Second License Agreement with respect to the filing, prosecution and maintenance of the patent rights licensed by us, to the extent not already paid by us under the A&R License Agreement.

Under the Second License Agreement, we must use commercially reasonable efforts to develop and commercialize one or more products in certain countries. As partial consideration for the rights conveyed by BCM under the Second License Agreement, we paid BCM a non-refundable license fee of $125,000. During the term of the Second License Agreement, we are obligated to pay BCM a non-refundable annual license maintenance fee of (a) $20,000 for the first through fourth anniversary of the effective date of the Second License Agreement, and (b) $40,000 for the fifth anniversary of the effective date and continuing thereafter, but beginning with the fifth year, license maintenance fees are fully creditable against royalty revenue due in the applicable year. We are required to pay certain milestone payments upon the achievement of specified clinical, regulatory, and sales milestones. In the event that we are able to successfully develop, launch and commercialize multiple products under the Second License Agreement, total milestone payments could exceed $30.0 million. BCM is also eligible to receive tiered royalties at percentage rates ranging from less than 1% to the low single-digits, on net sales of any products that are commercialized by us or our sublicensees that incorporate, utilize or are made with the use of, the intellectual property licensed by us. To the extent we sublicense our license rights under the Second License Agreement, BCM would be eligible to receive tiered sublicense income at percentage rates in the mid-single to low double-digits.

Sponsored Research Agreement with BCM

In June 2019, we entered into a sponsored research agreement, or SRA-2, with BCM, under which we agreed to pay BCM for performing certain research activities related to virus specific T-cell manufacturing for a one-year period, renewable for an additional one-year term upon written consent of both parties. SRA-2 requires us to make payments to BCM totaling $1.0 million, payable in four equal installments. SRA-2 was amended in March 2020 to include the discovery and development of allogeneic, off-the-shelf, virus specific T-cell therapies to combat SARS-CoV-2, the virus that causes COVID-19. In June 2020, a second amendment was entered into resulting in a no-cost extension through November 30, 2020, upon which the agreement terminated.

Collaboration Agreement with BCM

In November 2020, we entered into a Research Collaboration Agreement, or the Research Agreement, with BCM, under which we agreed to pay BCM for performing certain research activities under the direction of Dr. Ann Leen commencing on January 1, 2021, and continuing for a three-year period thereafter. The Research Agreement requires us to make payments to BCM totaling approximately $2.0 million per year, for a total of $6.0 million over the term of the Research Agreement.

Redeemable Preferred Stock Redemption Agreement

In September 2018, we entered into a redeemable preferred stock redemption agreement, or Redemption Agreement, to redeem shares of our Series A1 convertible preferred stock held by certain investors, including executive officer Ann Leen, director and former executive officer Juan Vera and entities affiliated with director, Malcolm Brenner and former director, John Wilson (or their affiliates). Pursuant to the Redemption Agreement, for a period of 20 years from the date of the first commercial sale of Viralym-M by us, we are obligated to make earnout payments to such investors on at least an annual basis. The earnout payments will be 10% of our net sales of Viralym-M, which number will be reduced to a high single-digit percentage if certain events occur. Specifically, royalties due to third parties for the sale of Viralym-M are subtracted from the earnout payments due to the investors. Further, if the investors receive at least $50,000,000 in earnout payments from us during the three-year period after the first commercial sale of Viralym-M, the earnout payment percentage will be reduced.

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Manufacturing

Our versatile VST manufacturing platform supports the rapid, robust and scalable generation of single- and multi-virus specific cell therapeutic candidates for clinical use. We leverage Cytokin™, our proprietary algorithm to select donors from whom to generate VSTs such that there is broad patient HLA coverage through an efficient set of donors. Virus-specific T-cells from individual healthy seropositive donors are expanded in a fully good manufacturing practices, or cGMP, compliant process, which is scaled to produce hundreds of patient doses from each manufacturing run. Our VST cell therapies are maintained in a cryopreserved state ready for “off-the-shelf” use. Cytomatch™, our proprietary algorithm for HLA matching, identifies the best VST cell line for each patient. In combination, these elements allow us to efficiently build our global supply chain to serve a growing number of patients who could benefit from our highly innovative off-the-shelf VST therapy candidates.

To facilitate investigational product supply for our posoleucel and ALVR106 clinical trials, we manufacture posoleucel and ALVR106 at external cGMP CMOs and leverage a network of cGLP contract testing laboratories. We believe this approach for our clinical product candidates is most cost-effective at our current clinical phase and production scale and has allowed us to rapidly prepare for clinical trials in accordance with our development plans.

Government Regulation

In the United States, biological products, are subject to regulation under the Federal Food, Drug, and Cosmetic Act, or FD&C Act, and the Public Health Service Act, or PHS Act, and other federal, state, local and foreign statutes and regulations. Both the FD&C Act and the PHS Act and their corresponding regulations govern, among other things, the research, development, clinical trial, testing, manufacturing, quality control, safety, efficacy, labeling, packaging, storage, record keeping, distribution, reporting, marketing, promotion, advertising, post-approval monitoring, and post-approval reporting involving biological products. The process of obtaining regulatory approvals and the subsequent compliance with appropriate federal, state, local and foreign statutes and regulations require the expenditure of substantial time and financial resources, and we may not be able to obtain the required regulatory approvals.

U.S. Biological Products Development Process

The process required by the FDA before a biological product may be marketed in the United States generally involves the following:

• completion of nonclinical laboratory tests and animal studies according to good laboratory practices, or GLPs, and applicable requirements for the humane use of laboratory animals or other applicable regulations;

• submission to the FDA of an application for an investigational new drug application, or IND, which must become effective before human clinical trials may begin;

• approval of the protocol and related documentation by an independent institutional review board, or IRB, or ethics committee at each clinical trial site before each study may be initiated;

• performance of adequate and well-controlled human clinical trials according to the FDA’s regulations commonly referred to as good clinical practices, or GCPs, and any additional requirements for the protection of human research subjects and their health information, to establish the safety and efficacy of the proposed biological product for its intended use;

• preparation of and submission to the FDA of a biologics license application, or BLA, for marketing approval that includes sufficient evidence of establishing the efficacy, safety, purity, and potency of the proposed biological product for its intended indication, including from results of nonclinical testing and clinical trials;

• satisfactory completion of an FDA inspection of the manufacturing facility or facilities where the biological product is produced to assess compliance with current good manufacturing practices, or cGMPs, to assure that the facilities, methods and controls are adequate to preserve the biological product’s identity, strength, quality and purity and, if applicable, the FDA’s current good tissue practices, or CGTPs, for human cellular and tissue products;

• potential FDA audit of the nonclinical study and clinical trial sites that generated the data in support of the BLA;

• review of the product candidate by an FDA advisory committee, where appropriate and if applicable;

• payment of user fees for FDA review of the BLA (unless a fee waiver applies); and

• FDA review and approval of the BLA, resulting in the licensure of the biological product for commercial marketing.

Before testing any biological product candidate, in humans, the product candidate enters the preclinical testing stage. Preclinical tests, also referred to as nonclinical studies, may include laboratory evaluations of product biological characteristics, chemistry, toxicity and formulation, as well as animal studies to assess the potential safety and activity of the product candidate. The conduct of the preclinical tests must comply with federal regulations and requirements including GLPs, if applicable.

Prior to beginning the first clinical trial with a product candidate in the United States, an IND must be submitted to the FDA and the FDA must allow the IND to proceed. An IND is an exemption from the FD&C Act that allows an unapproved product candidate to be shipped in interstate commerce for use in an investigational clinical trial and a request for FDA allowance that such investigational

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product may be administered to humans in connection with such trial. Such authorization must be secured prior to interstate shipment and administration. In support of a request for an IND, applicants must submit a protocol for each clinical trial and any subsequent protocol amendments must be submitted to the FDA as part of the IND. In addition, the results of the preclinical tests, together with manufacturing information, analytical data, any available clinical data or literature and plans for clinical trials, among other things, must be submitted to the FDA as part of an IND. An IND must become effective before human clinical trials may begin. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, raises safety concerns or questions about the proposed clinical trial. In such a case, the IND may be placed on clinical hold or partial clinical hold. In this case, the IND sponsor and the FDA must resolve any outstanding concerns before clinical trials can begin. Submission of an IND therefore may or may not result in FDA allowance to begin a clinical trial.

In addition to the submission of an IND to the FDA before initiation of a clinical trial in the United States, certain human clinical trials involving recombinant or synthetic nucleic acid molecules are subject to oversight of institutional biosafety committees, or IBCs, as set forth in the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, or NIH Guidelines. Under the NIH Guidelines, recombinant and synthetic nucleic acids are defined as: (i) molecules that are constructed by joining nucleic acid molecules and that can replicate in a living cell (i.e., recombinant nucleic acids); (ii) nucleic acid molecules that are chemically or by other means synthesized or amplified, including those that are chemically or otherwise modified but can base pair with naturally occurring nucleic acid molecules (i.e., synthetic nucleic acids); or (iii) molecules that result from the replication of those described in (i) or (ii). Specifically, under the NIH Guidelines, supervision of human gene transfer trials includes evaluation and assessment by an IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment, and such review may result in some delay before initiation of a clinical trial. While the NIH Guidelines are not mandatory unless the research in question is being conducted at or sponsored by institutions receiving NIH funding of recombinant or synthetic nucleic acid molecule research, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them.

Clinical trials involve the administration of the biological product candidate to healthy volunteers or patients under the supervision of qualified investigators who generally are physicians not employed by, or under, the control of, the trial sponsor. Clinical trials are conducted under written study protocols detailing, among other things, the objectives of the clinical trial, dosing procedures, subject selection and exclusion criteria and the parameters to be used to monitor subject safety, including stopping rules that assure a clinical trial will be stopped if certain adverse events should occur.

An IRB representing each institution participating in the clinical trial must review and approve the plan for any clinical trial before it commences at that institution, and the IRB must conduct continuing review and reapprove the study at least annually. The IRB must review and approve, among other things, the study protocol and informed consent information to be provided to study subjects. An IRB must operate in compliance with FDA regulations. An IRB can suspend or terminate approval of a clinical trial at its institution, or an institution it represents, if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the product candidate has been associated with unexpected serious harm to patients.

Some trials are overseen by an independent group of qualified experts organized by the trial sponsor, known as a data safety monitoring board or committee, or DSMB. This group provides authorization as to whether or not a trial may move forward at designated check points based on data from the ongoing study that are available to the DSMB members.

Certain information about certain clinical trials must also be submitted within specific timeframes to the NIH for public dissemination on its ClinicalTrials.gov website.

Clinical trials typically are conducted in three sequential phases that may overlap or be combined:

• Phase 1. The investigational product is initially introduced into healthy human subjects and tested for safety. In the case of some products for severe or life-threatening diseases, especially when the product may be too inherently toxic to ethically administer to healthy volunteers, the initial human testing is often conducted in patients.

• Phase 2. The investigational product is evaluated in a limited patient population to identify possible adverse effects and safety risks, to preliminarily evaluate the efficacy of the product for specific targeted diseases and to determine dosage tolerance, optimal dosage and dosing schedule.

• Phase 3. The investigational product is administered to an expanded patient population to further evaluate dosage, clinical efficacy, potency, and safety in an expanded patient population at geographically dispersed clinical trial sites. These clinical trials are intended to establish the overall risk/benefit ratio of the product and provide an adequate basis for approval and product labeling.

In some cases, FDA may require, or firms may voluntarily pursue, post-approval clinical trials, sometimes referred to as Phase 4 clinical trials, after initial marketing approval. These clinical trials are used to gain additional experience from the treatment of patients in the intended therapeutic indication, particularly for long-term safety follow-up. During all phases of clinical development, regulatory agencies require extensive monitoring and auditing of all clinical activities, clinical data, and clinical trial investigators. Annual progress reports detailing the results of the clinical trials must be submitted to the FDA. Written IND safety reports must be promptly submitted to the FDA and the investigators for serious and unexpected adverse events, any findings from other studies, tests in laboratory animals

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or in vitro testing that suggest a significant risk for human subjects, or any clinically important increase in the rate of a serious suspected adverse reaction over that listed in the protocol or investigator brochure. The sponsor must submit an IND safety report within 15 calendar days after the sponsor determines that the information qualifies for reporting. The sponsor also must notify the FDA of any unexpected fatal or life-threatening suspected adverse reaction within seven calendar days after the sponsor’s initial receipt of the information. Phase 1, Phase 2 and Phase 3 clinical trials may not be completed successfully within any specified period, if at all. The FDA or the sponsor, acting on its own or based on a recommendation from the sponsor’s data safety monitoring board, may suspend a clinical trial at any time on various grounds, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the biological product has been associated with unexpected serious harm to patients.

Concurrent with clinical trials, companies may complete additional animal studies and also must develop additional information about the physical characteristics of the biological product as well as finalize a process for manufacturing the product in commercial quantities in accordance with cGMP and as applicable CGTP requirements. To help reduce the risk of the introduction of adventitious agents with use of biological products, the PHS Act emphasizes the importance of manufacturing control for products whose attributes cannot be precisely defined. The manufacturing process must be capable of consistently producing quality batches of the product candidate and, among other things, the sponsor must develop methods for testing the identity, strength, quality, potency and purity of the final biological product. Additionally, appropriate packaging must be selected and tested and stability studies must be conducted to demonstrate that the biological product candidate does not undergo unacceptable deterioration over its shelf life.

U.S. Review and Approval Processes

Assuming successful completion of all required testing in accordance with all applicable regulatory requirements, the results of product development, nonclinical studies and clinical trials are submitted to the FDA as part of a BLA requesting approval to market the product for one or more indications. The BLA must include results of product development, laboratory and animal studies, human studies, information on the manufacture and composition of the product, proposed labeling and other relevant information.

Within 60 days following submission of the application, the FDA reviews a BLA submitted to determine if it is substantially complete before the FDA accepts it for filing. The FDA may refuse to file any BLA that it deems incomplete or not properly reviewable at the time of submission and may request additional information. In this event, the BLA must be resubmitted with the additional information. The resubmitted application also is subject to review to determine if it is substantially complete before the FDA accepts it for filing. In most cases, the submission of a BLA is subject to a substantial application user fee, although the fee may be waived under certain circumstances. Under the performance goals and policies implemented by the FDA under the Prescription Drug User Fee Act, or PDUFA, for original BLAs, the FDA targets ten months from the date FDA files the application (i.e., the filing date) in which to complete its initial review of a standard application and respond to the applicant, and six months from the filing date for an application granted priority review by FDA. The FDA does not always meet its PDUFA goal dates, and the review process is often significantly extended by FDA requests for additional information or clarification.

Once the submission is accepted for filing, the FDA begins an in-depth substantive review of the BLA. The FDA reviews the BLA to determine, among other things, whether the proposed product is safe, pure and potent, for its intended use, and whether the product is being manufactured in accordance with cGMP to ensure its continued safety, purity and potency. The FDA may refer applications for novel biological products or biological products that present difficult or novel questions of safety, efficacy, or quality to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendations of an advisory committee, but it considers such recommendations carefully when making decisions. During the biological product approval process, the FDA also will determine whether a Risk Evaluation and Mitigation Strategy, or REMS, is necessary to assure the safe use of the biological product. If the FDA concludes a REMS is needed, the sponsor of the BLA must submit a proposed REMS; the FDA will not approve the BLA without a REMS, if required.

Before approving a BLA, the FDA typically will inspect the facilities at which the product is manufactured. The FDA will not approve the product unless it determines that the manufacturing processes and facilities are in compliance with cGMP requirements and adequate to assure consistent production of the product within required specifications. Where applicable, the FDA also will not approve the product if the manufacturer is not in compliance with the CGTPs. These are FDA regulations that govern the methods used in, and the facilities and controls used for, the manufacture of human cells, tissues, and cellular and tissue-based products, or HCT/Ps, which are human cells or tissue intended for implantation, transplant, infusion, or transfer into a human patient. The primary intent of the CGTP requirements is to ensure that cell and tissue-based products are manufactured in a manner designed to prevent the introduction, transmission and spread of communicable disease. FDA regulations also require tissue establishments to register and list their HCT/Ps with the FDA and, when applicable, to evaluate donors through appropriate screening and testing. Additionally, before approving a BLA, the FDA will typically inspect one or more clinical sites to assure that the clinical trials were conducted in compliance with IND study requirements and GCP requirements. To ensure cGMP, CGTP and GCP compliance, an applicant must incur significant expenditure of time, money and effort in the areas of training, record keeping, production and quality control.

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Under the Pediatric Research Equity Act, or PREA, a BLA or supplement to a BLA for a novel product (e.g., new active ingredient, new indication, etc.) must contain data to assess the safety and effectiveness of the biological product for the claimed indications in all relevant pediatric subpopulations and to support dosing and administration for each pediatric subpopulation for which the product is safe and effective. The FDA may grant deferrals for submission of data or full or partial waivers. Unless otherwise required by regulation, PREA does not apply to any biological product for an indication for which orphan designation has been granted.

After the FDA evaluates a BLA and conducts inspections of manufacturing facilities where the investigational product and/or its drug substance will be produced, the FDA may issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the product with specific prescribing information for specific indications. A Complete Response Letter will describe all of the deficiencies that the FDA has identified in the BLA, except that where the FDA determines that the data supporting the application are inadequate to support approval, the FDA may issue the Complete Response Letter without first conducting required inspections, testing submitted product lots, and/or reviewing proposed labeling. In issuing the Complete Response Letter, the FDA may recommend actions that the applicant might take to place the BLA in condition for approval, including requests for additional information or clarification. The FDA may delay or refuse approval of a BLA if applicable regulatory criteria are not satisfied, require additional testing or information and/or require post-marketing testing and surveillance to monitor safety or efficacy of a product.

If a product receives regulatory approval, the approval may be significantly limited to specific diseases and dosages or the indications for use may otherwise be limited, including to subpopulations of patients, which could restrict the commercial value of the product. Further, the FDA may require that certain contraindications, warnings precautions or interactions be included in the product labeling. The FDA may impose restrictions and conditions on product distribution, prescribing, or dispensing in the form of a REMS, or otherwise limit the scope of any approval. The FDA also may condition approval on, among other things, changes to proposed labeling or the development of adequate controls and specifications. Once approved, the FDA may withdraw the product approval if compliance with pre- and post-marketing requirements is not maintained or if problems occur after the product reaches the marketplace. The FDA may require one or more Phase IV post-market studies and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization, and may limit further marketing of the product based on the results of these post-marketing studies.

Orphan Drug Designation

Under the Orphan Drug Act, the FDA may grant orphan designation to a drug or biological product intended to treat a rare disease or condition, which is generally a disease or condition that affects fewer than 200,000 individuals in the United States, or more than 200,000 individuals in the United States and for which there is no reasonable expectation that the cost of developing and making a drug or biological product available in the United States for this type of disease or condition will be recovered from sales of the product. Orphan product designation must be requested before submitting a BLA. After the FDA grants orphan product designation, the identity of the therapeutic agent and its potential orphan use are disclosed publicly by the FDA. Orphan product designation does not convey any advantage in or shorten the duration of the regulatory review and approval process.

If a product that has orphan drug designation subsequently receives the first FDA approval for a particular active ingredient for the disease for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications, including a full BLA, to market the same biologic for the same indication for seven years, except in limited circumstances, such as a showing of clinical superiority to the product with orphan drug exclusivity or if the FDA finds that the holder of the orphan drug exclusivity has not shown that it can assure the availability of sufficient quantities of the orphan drug to meet the needs of patients with the disease or condition for which the drug was designated. Orphan drug exclusivity does not prevent the FDA from approving a different drug or biologic for the same disease or condition, or the same drug or biologic for a different disease or condition. Among the other benefits of orphan drug designation are tax credits for certain research and a waiver of the BLA application user fee.

A designated orphan drug may not receive orphan drug exclusivity if it is approved for a use that is broader than the indication for which it received orphan designation. In addition, orphan drug exclusive marketing rights in the United States may be lost if the FDA later determines that the request for designation was materially defective or, as noted above, if the second applicant demonstrates that its product is clinically superior to the approved product with orphan exclusivity or the manufacturer of the approved product is unable to assure sufficient quantities of the product to meet the needs of patients with the rare disease or condition.

Orphan drug designation may also entitle a party to financial incentives such as opportunities for grant funding towards clinical trial costs, tax advantages and user-fee waivers.

Expedited Development and Review Programs

The FDA has various programs, including Fast Track designation, breakthrough therapy designation, accelerated approval and priority review, that are intended to expedite or simplify the process for the development and FDA review of drugs and biologics that are intended for the treatment of serious or life-threatening diseases or conditions. To be eligible for fast track designation, new drugs and biological product candidates must be intended to treat a serious or life-threatening condition and demonstrate the potential to address unmet medical needs for the condition. Fast Track designation applies to the combination of the product and the specific indication for which it is being studied. The sponsor of a new drug or biologic may request the FDA to designate the drug or biologic

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as a fast track product at any time during the clinical development of the product. One benefit of fast track designation, for example, is that the FDA may consider for review sections of the marketing application on a rolling basis before the complete application is submitted if certain conditions are satisfied, including an agreement with the FDA on the proposed schedule for submission of portions of the application and the payment of applicable user fees before the FDA may initiate a review.

Under the FDA’s breakthrough therapy program, a sponsor may seek FDA designation of its product candidate as a breakthrough therapy if the product candidate is intended, alone or in combination with one or more other drugs or biologics, to treat a serious or life-threatening disease or condition and preliminary clinical evidence indicates that it may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. Breakthrough therapy designation comes with all of the benefits of fast track designation, which means that the sponsor may file sections of the BLA for review on a rolling basis if certain conditions are satisfied, including an agreement with the FDA on the proposed schedule for submission of portions of the application and the payment of applicable user fees before the FDA may initiate a review. The FDA may take other actions appropriate to expedite the development and review of the product candidate, including holding meetings with the sponsor and providing timely advice to, and interactive communication with, the sponsor regarding the development program.

A product candidate is eligible for priority review if it treats a serious or life-threatening disease or condition and, if approved, would provide a significant improvement in the safety or effectiveness of the treatment, diagnosis or prevention of a serious disease or condition. The FDA will attempt to direct additional resources to the evaluation of an application for a new drug or biological product designated for priority review in an effort to facilitate the review. Under priority review, the FDA’s goal is to review an application in six months once it is filed, compared to ten months for a standard review. Priority review designation does not change the scientific/medical standard for approval or the quality of evidence necessary to support approval.

Additionally, a product candidate may be eligible for accelerated approval. Drug or biological products studied for their safety and effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments may receive accelerated approval, which means that they may be approved on the basis of adequate and well-controlled clinical trials establishing that the product has an effect on a surrogate endpoint that is reasonably likely to predict a clinical benefit, or on the basis of an effect on an intermediate clinical endpoint other than survival or irreversible morbidity, taking into account the severity, rarity, or prevalence of the condition and the availability or lack of alternative treatments. As a condition of approval, the FDA generally requires that a sponsor of a drug or biological product receiving accelerated approval perform adequate and well-controlled post-marketing clinical trials with due diligence and, under the Food and Drug Omnibus Reform Act of 2022, or FDORA, the FDA is now permitted to require, as appropriate, that such trials be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. In addition, for products being considered for accelerated approval, unless otherwise informed by the FDA, the FDA generally requires, that all advertising and promotional materials intended for dissemination or publication within 120 days following marketing approval be submitted to the agency for review during the pre-approval review period, and that after 120 days following marketing approval, all advertising and promotional materials must be submitted at least 30 days prior to the intended time of initial dissemination or publication. Under FDORA, the FDA has increased authority for expedited procedures to withdraw approval of a drug or indication approved under accelerated approval if, for example, the confirmatory trial fails to verify the predicted clinical benefit of the product.

RMAT Designation

As part of the 21st Century Cures Act, enacted in December 2016, Congress created the Regenerative Medicine Advanced Therapy, or RMAT, designation to facilitate an efficient development program for, and expedite review of, a product candidate that meets the following criteria: (1) it qualifies as a RMAT, which is defined as a cell therapy, therapeutic tissue engineering product, human cell and tissue product, or any combination product using such therapies or products, with limited exceptions; (2) it is intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition; and (3) preliminary clinical evidence indicates that the drug has the potential to address unmet medical needs for such a disease or condition. A sponsor may request that the FDA designate a drug as a RMAT concurrently with or at any time after submission of an IND. The FDA has 60 calendar days to determine whether the drug meets the criteria. A BLA for a regenerative medicine therapy that has received RMAT designation may be eligible for priority review or accelerated approval through use of surrogate or intermediate endpoints reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of sites. Benefits of RMAT designation also include early interactions with FDA to discuss any potential surrogate or intermediate endpoint to be used to support accelerated approval. A regenerative medicine therapy with RMAT designation that is granted accelerated approval and is subject to post-approval requirements may, as appropriate, fulfill such requirements through the submission of clinical evidence from clinical trials, patient registries, or other sources of real world evidence, such as electronic health records; the collection of larger confirmatory data sets; or post-approval monitoring of all patients treated with such therapy prior to its approval. Like some of FDA’s other expedited development programs, RMAT designation does not change the standards for approval but may help expedite the development or approval process.

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Post-approval Requirements

Rigorous and extensive FDA regulation of biological products continues after approval, particularly with respect to cGMP requirements, as well as requirements relating to record-keeping, reporting of adverse experiences, periodic reporting, product sampling and distribution, and advertising and promotion of the product. We currently rely, and may continue to rely, on third parties for the production of clinical and commercial quantities of any products that we may commercialize. Manufacturers of our products are required to comply with applicable requirements in the cGMP regulations, including quality control and quality assurance and maintenance of records and documentation. Other post-approval requirements applicable to biological products, include reporting of cGMP deviations that may affect the identity, potency, purity and overall safety of a distributed product, record-keeping requirements, reporting of adverse effects, reporting updated safety and efficacy information, and complying with electronic record and signature requirements. As part of the manufacturing process, the manufacturer is required to perform certain tests on each lot of the product before it is released for distribution. After a BLA is approved for a biological product, the product also may be subject to official lot release. If the product is subject to official release by the FDA, the manufacturer submits samples of each lot of product to the FDA together with a release protocol showing a summary of the history of manufacture of the lot and the results of all of the manufacturer’s tests performed on the lot. The FDA also may perform certain confirmatory tests on lots of some products before releasing the lots for distribution by the manufacturer. In addition, the FDA conducts laboratory research related to the regulatory standards on the safety, purity, potency, and effectiveness of biological products.

Manufacturers also must comply with the FDA’s advertising and promotion requirements, such as those related to direct-to-consumer advertising, the prohibition on promoting products for uses or in patient populations that are not described in the product’s approved labeling (known as “off-label use”), industry-sponsored scientific and educational activities, and promotional activities involving the internet. Discovery of previously unknown problems or the failure to comply with the applicable regulatory requirements may result in restrictions on the marketing of a product or withdrawal of the product from the market as well as possible civil or criminal sanctions.

Failure to comply with the applicable United States requirements at any time during the product development process, approval process or after approval, may subject an applicant or manufacturer to administrative or judicial civil or criminal sanctions and adverse publicity. FDA sanctions could include refusal to approve pending applications, withdrawal of an approval, clinical holds, warning or untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, product detentions or refusal to permit the import or export of the product, restrictions on the marketing or manufacturing of the product, injunctions, fines, refusals of government contracts, mandated corrective advertising or communications with doctors or other stakeholders, debarment, restitution, disgorgement of profits, or civil or criminal penalties. Any agency or judicial enforcement action could have a material adverse effect on us.

Biological product manufacturers and other entities involved in the manufacture and distribution of approved biological products, and those supplying products, ingredients, and components of them, are required to register their establishments with the FDA and certain state agencies, and they are subject to periodic unannounced inspections by the FDA and certain state agencies for compliance with cGMP and other laws. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain cGMP compliance. Manufacturers and other parties involved in the drug supply chain for prescription drug products must also comply with product tracking and tracing requirements and for notifying the FDA of counterfeit, diverted, stolen and intentionally adulterated products or products that are otherwise unfit for distribution in the United States. Additionally, discovery of problems with a product after approval may result in restrictions on a product, manufacturer, or holder of an approved BLA, including withdrawal of the product from the market. In addition, changes to the manufacturing process or facility generally require prior FDA approval before being implemented and other types of changes to the approved product, such as adding new indications and additional labeling claims, are also subject to further FDA review and approval.

Marketing Exclusivity

Depending upon the timing, duration and specifics of the FDA approval of the use of our product candidates, some of our United States patents may be eligible for limited patent term extension under the Hatch-Waxman Amendments. The Hatch-Waxman Amendments permit a patent restoration term of up to five years as compensation for patent term lost during product development and the FDA regulatory review process. However, patent term restoration cannot extend the remaining term of a patent beyond a total of 14 years from the product’s approval date. The patent term restoration period is generally one-half the time between the effective date of an IND and the submission date of a BLA plus the time between the submission date of a BLA and the approval of that application. Only one patent applicable to an approved biological product is eligible for the extension and the application for the extension must be submitted prior to the expiration of the patent. In addition, a patent can only be extended once and only for a single product. The U.S. PTO, in consultation with the FDA, reviews and approves the application for any patent term extension or restoration. In the future, we may intend to apply for restoration of patent term for one of our patents, if and as applicable, to add patent life beyond its current expiration date, depending on the expected length of the clinical trials and other factors involved in the filing of the relevant BLA.

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The Affordable Care Act, or ACA, signed into law on March 23, 2010, includes a subtitle called the Biologics Price Competition and Innovation Act of 2009, or BPCIA, which created an abbreviated approval pathway for biological products shown to be biosimilar to, or interchangeable with, an FDA-licensed reference biological product. This amendment to the PHS Act attempts to minimize duplicative testing. Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, can be shown through analytical studies, animal studies, and a clinical trial or trials. Interchangeability requires that a product is biosimilar to the reference product and the product must demonstrate that it can be expected to produce the same clinical results as the reference product and, for products administered multiple times, the biologic and the reference biologic may be switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic.

FDA will not accept an application for a biosimilar or interchangeable product based on the reference biological product until four years after the date of first licensure of the reference product, and FDA will not approve an application for a biosimilar or interchangeable product based on the reference biological product until twelve years after the date of first licensure of the reference product. “First licensure” typically means the initial date the particular product at issue was licensed in the United States. Date of first licensure does not include the date of licensure of (and a new period of exclusivity is not available for) a biological product if the licensure is for a supplement for the biological product or for a subsequent application by the same sponsor or manufacturer of the biological product (or licensor, predecessor in interest, or other related entity) for a change (not including a modification to the structure of the biological product) that results in a new indication, route of administration, dosing schedule, dosage form, delivery system, delivery device or strength, or for a modification to the structure of the biological product that does not result in a change in safety, purity, or potency.

The BPCIA is complex and continues to be interpreted and implemented by the FDA. In addition, government proposals have sought to reduce the 12-year reference product exclusivity period. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation. As a result, the ultimate impact, implementation, and impact of the BPCIA is subject to significant uncertainty.

In addition to exclusivity under the BPCIA, a biological product can obtain pediatric market exclusivity in the United States. Pediatric exclusivity, if granted, adds six months to existing exclusivity periods, including some regulatory exclusivity periods tied to patent terms. This six-month exclusivity, which runs from the end of other exclusivity protection or patent term, may be granted based on the voluntary completion of a pediatric study in accordance with an FDA-issued “Written Request” for such a study.

Additional Regulation

In addition to the foregoing, state and federal laws regarding environmental protection and hazardous substances, including the Occupational Safety and Health Act, the Resource Conservancy and Recovery Act and the Toxic Substances Control Act, affect our business. These and other laws govern our use, handling and disposal of various biological, chemical and radioactive substances used in, and wastes generated by, our operations. If our operations result in contamination of the environment or expose individuals to hazardous substances, we could be liable for damages and governmental fines. We believe that we are in material compliance with applicable environmental laws and that continued compliance therewith will not have a material adverse effect on our business. We cannot predict, however, how changes in these laws may affect our future operations.

U.S. Foreign Corrupt Practices Act, U.K. Bribery Act and Other Laws

The U.S. Foreign Corrupt Practices Act of 1977, or FCPA, prohibits United States corporations and individuals from engaging in certain activities to obtain or retain business or secure any improper advantage, or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any employee or official of a foreign government or public international organization, or political party, political party official, or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in an official capacity. The scope of the FCPA also includes employees and officials of state- owned or controlled enterprises, which may include healthcare professionals in many countries. Equivalent laws have been adopted in other foreign countries that impose similar obligations.

Our operations are also subject to non-United States anti-corruption laws such as the U.K. Bribery Act 2010, or the Bribery Act. As with the FCPA, these laws generally prohibit us and our employees and intermediaries from authorizing, promising, offering, or providing, directly or indirectly, improper or prohibited payments, or anything else of value, to government officials or other persons to obtain or retain business or gain some other business advantage. Under the Bribery Act, we may also be liable for failing to prevent a person associated with us from committing a bribery offense.

We are also subject to other laws and regulations governing our international operations, including regulations administered by the governments of the United Kingdom and the United States and authorities in the European Union, including applicable export control regulations, economic sanctions and embargoes on certain countries and persons, anti-money laundering laws, import and customs requirements and currency exchange regulations, collectively referred to as trade control laws.

Failure to comply with the Bribery Act, the FCPA and other anti-corruption laws and trade control laws could subject us to criminal and civil penalties, disgorgement and other sanctions and remedial measures, and legal expenses.

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Government Regulation Outside of the United States

In addition to regulations in the United States, we are subject to a variety of regulations in other jurisdictions governing, among other things, research and development, clinical trials, testing, manufacturing, safety, efficacy, labeling, packaging, storage, record keeping, distribution, reporting, advertising and other promotional practices involving biological products as well as authorization and approval of our products. Because biologically sourced raw materials are subject to unique contamination risks, their use may be restricted in some countries.

The requirements and processes governing the conduct of clinical trials, product licensing, pricing and reimbursement vary from country to country. In all cases, the clinical trials must be conducted in accordance with GCP and the applicable regulatory requirements and the ethical principles that have their origin in the Declaration of Helsinki.

If we fail to comply with applicable foreign regulatory requirements, we may be subject to, among other things, fines, suspension of clinical trials, suspension or withdrawal of regulatory approvals, product recalls, seizure of products, operating restrictions and criminal prosecution.

Clinical Trials Regulation

Whether or not we obtain FDA approval for a product, we must obtain the requisite approvals from regulatory authorities in foreign countries prior to the commencement of clinical trials or marketing of the product in those countries. Certain countries outside of the United States have a similar process that requires the submission of a clinical trial application much like the IND prior to the commencement of human clinical trials. In the European Union, for example, a CTA must be submitted for each clinical trial to each country’s National Competent Authority, or NCA, and at least one independent Ethics Committee, or EC, much like the FDA and an IRB, respectively. Once the CTA is approved in accordance with a country’s requirements, the corresponding clinical trial may proceed. Under the current regime (the EU Clinical Trials Directive 2001/20/EC and corresponding national laws) all suspected unexpected serious adverse reactions to the investigational drug that occur during the clinical trial have to be reported to the NCA and ECs of the European Union Member State where they occurred.

In April 2014, the European Union adopted a new Clinical Trials Regulation (EU) No 536/2014, which is set to replace the current Clinical Trials Directive 2001/20/EC. It will overhaul the current system of approvals for clinical trials in the European Union. Specifically, the new Clinical Trials Regulation, which will be directly applicable in all Member States (meaning that no national implementing legislation in each European Union Member State is required), aims at simplifying and streamlining the approval of clinical trials in the European Union. For instance, the new Clinical Trials Regulation provides for a streamlined application procedure via a single entry point and strictly defined deadlines for the assessment of clinical trial applications. It is expected that the new Clinical Trials Regulation will come into effect following confirmation of full functionality of the Clinical Trials Information System, the centralized European Union portal and database for clinical trials foreseen by the new Clinical Trials regulation, through an independent audit, which is currently expected to occur in January 2023.

Drug Review and Approval

In the European Economic Area (comprised of the European Union Member States plus Norway, Iceland and Liechtenstein), or EEA, medicinal products, including advanced therapy medicinal products, or ATMPs, are subject to extensive pre- and post-market regulation by regulatory authorities at both the EEA and national levels. Under Article 2(1) of Regulation (EC) No 1394/2007, or the ATMP Regulation, ATMPs comprise gene therapy products, somatic cell therapy products and tissue engineered products. Somatic cell therapy products comprise cells that have undergone substantial manipulation so that biological characteristics, physiological functions or structural properties relevant for the intended clinical use have been altered, where such cells are to be administered to human beings in order to cure, diagnose or prevent disease. We anticipate that our current development products are somatic cell therapy medical products which would be regulated as ATMPs in the EEA.

To obtain regulatory approval of ATMP in the EEA, we must submit a marketing authorization application, or MAA, under the centralized procedure administered by the European Medicines Agency, or EMA. The centralized procedure provides for the grant of a single marketing authorization by the European Commission that is valid across all of the EEA. As provided for in the ATMP Regulation, the scientific evaluation of MAAs for ATMPs is primarily performed by a specialized scientific committee called the Committee for Advanced Therapies, or CAT. The CAT prepares a draft opinion on the quality, safety and efficacy of the ATMP which is the subject of the MAA, which is sent for final approval to the Committee for Medicinal Products for Human Use, or CHMP. The CHMP recommendation is then sent to the European Commission, which adopts a decision binding in all EEA Member States. The maximum timeframe for the evaluation of an MAA for an ATMP is 210 days from receipt of a valid MAA, excluding clock stops when additional information or written or oral explanation is to be provided by the applicant in response to questions of the CAT and/or CHMP. Clock stops may extend the timeframe of evaluation of a MAA considerably beyond 210 days. Where the CHMP gives a positive opinion, the EMA provides the opinion together with supporting documentation to the European Commission, who make the final decision to grant a marketing authorization, which is issued within 67 days of receipt of the EMA’s recommendation. Accelerated assessment may be

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granted by the CHMP in exceptional cases, when a medicinal product is of major interest from the point of view of public health and, in particular, from the viewpoint of therapeutic innovation. If the CHMP accepts such a request, the timeframe of 210 days for assessment will be reduced to 150 days (excluding clock stops), but it is possible that the CHMP may revert to the standard time limit for the centralized procedure if it determines that the application is no longer appropriate to conduct an accelerated assessment.

The application used to submit the BLA in the United States is similar to that required in the European Union, with the exception of, among other things, certain specific requirements set out in the ATMP Regulation, for example certain particulars to be contained in the summary of product characteristics. A MAA holder for an ATMP in Europe must also put in place a system to ensure that each individual product, and its starting and raw materials, can be traced through the sourcing, manufacturing, packaging, storage, transport and delivery to the relevant healthcare institution.

Now that the UK (which comprises Great Britain and Northern Ireland) has left the European Union, Great Britain will no longer be covered by centralized marketing authorizations (under the Northern Irish Protocol, centralized marketing authorizations will continue to be recognized in Northern Ireland). All medicinal products with a current centralized marketing authorization were automatically converted to Great Britain marketing authorizations on January, 1 2021. For a period of two years from January 1, 2021, the Medicines and Healthcare products Regulatory Agency, or MHRA, the UK medicines regulator, may rely on a decision taken by the European Commission on the approval of a new marketing authorization in the centralized procedure, in order to more quickly grant a new Great Britain marketing authorization. A separate application will, however, still be required.

Data and Marketing Exclusivity

The EEA also provides opportunities for market exclusivity. Upon receiving a marketing authorization in the EEA, innovative medicinal products generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, data exclusivity prevents generic or biosimilar applicants from referencing the innovator’s pre-clinical or clinical trial data contained in the dossier of the reference product when applying for a generic or biosimilar marketing authorization during a period of eight years from the date on which the reference product was first authorized in the EEA. During the additional two-year period of market exclusivity, a generic or biosimilar marketing authorization can be submitted, and the innovator’s data may be referenced, but no generic or biosimilar product can be marketed until the expiration of the market exclusivity period. The overall ten-year period will be extended to a maximum of eleven years if, during the first eight years of those ten years, the marketing authorization holder obtains an authorization for one or more new therapeutic indications which, during the scientific evaluation prior to authorization, is held to bring a significant clinical benefit in comparison with existing therapies. Even if an innovative medicinal product gains the prescribed period of data exclusivity, another company may market another version of the product if such company obtained marketing authorization based on a MAA with a complete independent data package of pharmaceutical tests, preclinical tests and clinical trials.

Orphan Drug Designation and Exclusivity

Products with an orphan designation in the EEA can receive ten years of market exclusivity, during which time “no similar medicinal product” for the same indication may be placed on the market. A “similar medicinal product” is defined as a medicinal product containing a similar active substance or substances as contained in an authorized orphan medicinal product, and which is intended for the same therapeutic indication. An orphan product can also obtain an additional two years of market exclusivity in the European Union where an agreed Pediatric Investigation Plan for pediatric studies has been complied with. No extension to any supplementary protection certificate can be granted on the basis of pediatric studies for orphan indications.

The criteria for designating an “orphan medicinal product” in the European Union are similar in principle to those in the United States. Under Article 3 of Regulation (EC) 141/2000, a medicinal product may be designated as an orphan medicinal product if it meets the following criteria: (1) it is intended for the diagnosis, prevention or treatment of a life-threatening or chronically debilitating condition; (2) either the prevalence of such condition must not be more than five in 10,000 persons in the European Union when the application is made, or without the benefits derived from orphan status, it must be unlikely that the marketing of the medicine would generate sufficient return in the EEA to justify the investment needed for its development; and (3) there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the EEA, or if such a method exists, the product will be of significant benefit to those affected by the condition, as defined in Regulation (EC) 847/2000. Orphan medicinal products are eligible for financial incentives such as reduction of fees or fee waivers and are, upon grant of a marketing authorization, entitled to ten years of market exclusivity for the approved therapeutic indication. The application for orphan drug designation must be submitted before the application for marketing authorization. The applicant will receive a fee reduction for the MAA if the orphan drug designation has been granted, but not if the designation is still pending at the time the marketing authorization is submitted. Orphan drug designation does not convey any advantage in, or shorten the duration of, the regulatory review and approval process.

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The ten year market exclusivity may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation, for example, if the product is sufficiently profitable not to justify maintenance of market exclusivity. Otherwise, orphan medicine marketing exclusivity may be revoked only in very select cases, such as if:

• it is established that a similar medicinal product is safer, more effective or otherwise clinically superior;

• the marketing authorization holder consents to a second orphan medicinal product application; or

• the marketing authorization holder cannot supply enough orphan medicinal product.

From January 1, 2021, a separate process for orphan drug designation will apply in Great Britain. There will be no pre-marketing authorization orphan designation (as there is in the EEA) and the application for orphan designation will be reviewed by the MHRA at the time of the marketing authorization application. The criteria are the same as in the EEA, save that they apply to Great Britain only (e.g. there must be no satisfactory method of diagnosis, prevention or treatment of the condition concerned in Great Britain).

Pediatric Development

In the EEA, companies developing a new medicinal product must agree upon a Pediatric Investigation Plan, or PIP, with the EMA’s Pediatric Committee, or PDCO, and must conduct pediatric clinical trials in accordance with that PIP, unless a waiver applies, (e.g., because the relevant disease or condition occurs only in adults). The PIP sets out the timing and measures proposed to generate data to support a pediatric indication of the drug for which marketing authorization is being sought. The marketing authorization application for the product must include the results of pediatric clinical trials conducted in accordance with the PIP, unless a waiver applies, or a deferral has been granted by the PDCO of the obligation to implement some or all of the measures of the PIP until there are sufficient data to demonstrate the efficacy and safety of the product in adults, in which case the pediatric clinical trials must be completed at a later date. Products that are granted a marketing authorization with the results of pediatric clinical trials conducted in accordance with the PIP are eligible for a six month extension of the protection under a supplementary protection certificate (if any is in effect at the time of approval) even where the trial results are negative. In the case of orphan medicinal products, a two year extension of the orphan market exclusivity. This pediatric reward is subject to specific conditions and is not automatically available when data in compliance with the PIP are developed and submitted.

PRIME Designation

In March 2016, the European Medicines Agency, or EMA, launched an initiative to facilitate development of product candidates in indications, often rare, for which few or no therapies currently exist. The PRIority Medicines, or PRIME, scheme is intended to encourage drug development in areas of unmet medical need and provides accelerated assessment of products representing substantial innovation, where the marketing authorization application will be made through the centralized procedure. Eligible products must target conditions for which where is an unmet medical need (there is no satisfactory method of diagnosis, prevention or treatment in the EEA or, if there is, the new medicine will bring a major therapeutic advantage) and they must demonstrate the potential to address the unmet medical need by introducing new methods of therapy or improving existing ones. Products from small- and medium-sized enterprises may qualify for earlier entry into the PRIME scheme than larger companies. Many benefits accrue to sponsors of product candidates with PRIME designation, including but not limited to, early and proactive regulatory dialogue with the EMA, frequent discussions on clinical trial designs and other development program elements, and accelerated marketing authorization application assessment once a dossier has been submitted. Importantly, a dedicated Agency contact and rapporteur from the Committee for Human Medicinal Products, or CHMP, or Committee for Advanced Therapies are appointed early in PRIME scheme facilitating increased understanding of the product at EMA’s Committee level. A kick-off meeting initiates these relationships and includes a team of multidisciplinary experts at the EMA to provide guidance on the overall development and regulatory strategies. Where, during the course of development, a medicine no longer meets the eligibility criteria, support under the PRIME scheme may be withdrawn.

Post-Approval Controls

Following approval, the holder of the marketing authorization is required to comply with a range of requirements applicable to the manufacturing, marketing, promotion and sale of the medicinal product. These include the following:

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Brexit and the Regulatory Framework in the United Kingdom

In June 2016, the electorate in the United Kingdom voted in favor of leaving the European Union (commonly referred to as “Brexit”). Thereafter, in March 2017, the country formally notified the European Union of its intention to withdraw pursuant to Article 50 of the Lisbon Treaty. The United Kingdom formally left the European Union on January 31, 2020. A transition period began on February 1, 2020, during which European Union pharmaceutical law remained applicable to the United Kingdom, and ended on December 31, 2020. Since the regulatory framework for pharmaceutical products in the United Kingdom covering quality, safety and efficacy of pharmaceutical products, clinical trials, marketing authorization, commercial sales and distribution of pharmaceutical products is derived from European Union Directives and Regulations, Brexit could materially impact the future regulatory regime which applies to products and the approval of product candidates in the United Kingdom, as the United Kingdom legislation now has the potential to diverge from European Union legislation. It remains to be seen how Brexit will impact regulatory requirements for product candidates and products in the United Kingdom in the long term. The MHRA has recently published detailed guidance for industry and organizations to follow now the transition period is over, which will be updated as the United Kingdom’s regulatory position on medicinal products and medical devices evolves over time.

Coverage and Reimbursement

Sales of our products will depend, in part, on the extent to which our products will be covered by third-party payors, such as government health programs, commercial insurance and managed healthcare organizations. In the U.S., no uniform policy of coverage and reimbursement for drug or biological products exists. Accordingly, decisions regarding the extent of coverage and amount of reimbursement to be provided for any of our products will be made on a payor-by-payor basis. The process for determining whether a third-party payor will provide coverage for a product may be separate from the process for setting the price or reimbursement rate that the payor will pay for the product once coverage is approved. Third-party payors are increasingly challenging the prices charged, examining the medical necessity, and reviewing the cost-effectiveness of medical products and services and imposing controls to manage costs. The coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be obtained.

In the United States and in other countries, patients generally rely on third-party payors to reimburse all or part of the costs associated with their treatment. Adequate coverage and reimbursement from governmental healthcare programs, such as Medicare and Medicaid, and commercial payors is critical to new product acceptance. Our ability to successfully commercialize our product candidates will depend in part on the extent to which coverage and adequate reimbursement for these products and related treatments will be available from government health administration authorities, private health insurers and other organizations. Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. The availability of coverage and extent of reimbursement by governmental and private payors is essential for most patients to be able to afford treatments such as cell or gene therapy products. Sales of these or other product candidates that we may identify will depend substantially, both domestically and abroad, on the extent to which the costs of our product candidates will be paid by health maintenance, managed care, and similar healthcare management organizations, or reimbursed by government health administration authorities, private health coverage insurers and other third-party payors. If coverage and adequate reimbursement are not available, or are available only to limited levels, we may not be able to successfully commercialize our product candidates. Even if coverage is provided, the approved reimbursement amount may not be high enough to allow us to establish or maintain pricing sufficient to realize a sufficient return on our investment. For products administered under the supervision of a physician, obtaining coverage and adequate reimbursement may be particularly difficult because of the higher prices often associated with such drugs. Additionally, separate reimbursement for the product itself or the treatment or procedure in which the product is used may not be available, which may impact physician utilization.

There is also significant uncertainty related to the insurance coverage and reimbursement of newly approved products and coverage may be more limited than the purposes for which the medicine is approved by the FDA or comparable foreign regulatory

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authorities. In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services, or HHS. CMS decides whether and to what extent a new medicine will be covered and reimbursed under Medicare, and private payors tend to follow CMS to a substantial degree. Factors a payor considers in determining reimbursement are based on whether the product is:

Net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States.

Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. We cannot be sure that reimbursement will be available for any product candidate that we commercialize and, if reimbursement is available, the level of reimbursement.

In addition, many pharmaceutical manufacturers must calculate and report certain price reporting metrics to the government, such as average sales price, or ASP, and best price. Penalties may apply in some cases when such metrics are not submitted accurately and timely. Further, these prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs.

Many third-party payors are increasingly limiting both coverage and the level of reimbursement of new drugs. Increasingly, third-party payors are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. We cannot be sure that reimbursement will be available for any product candidate that we commercialize and, if reimbursement is available, the level of reimbursement. In addition, many pharmaceutical manufacturers must calculate and report certain price reporting metrics to the government, such as average sales price, or ASP, and best price. Penalties may apply in some cases when such metrics are not submitted accurately and timely. Further, these prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payors and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States.

In addition, in some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, the European Union provides options for its Member States to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical trials that compare the cost effectiveness of a particular product candidate to currently available therapies. A Member State may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. There can be no assurance that any country that has price controls or reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our product candidates. Historically, products launched in the European Union do not follow price structures of the U.S. and generally prices tend to be significantly lower.

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Other Healthcare Laws and Compliance Requirements

In the United States, our current and future operations are subject to regulation by various federal, state and local authorities in addition to the FDA, including but not limited to, CMS, other divisions of the United States Department of Health and Human Service, or HHS, (such as the Office of Inspector General, Office for Civil Rights and the Health Resources and Service Administration), the U.S. Department of Justice, or DOJ, and individual U.S. Attorney offices within the DOJ, and state and local governments. Our clinical research, sales, marketing and scientific/educational grant programs may be subject to the following laws, each as amended, as applicable:

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Because of the breadth of these laws and the narrowness of the statutory exceptions and safe harbors available, it is possible that some of our business activities could be subject to challenge under one or more of such laws.

Government enforcement agencies have shown increased interest in pharmaceutical companies' product and patient assistance programs, including reimbursement support services, and a number of investigations into these programs have resulted in significant civil and criminal settlements. In addition, at least one insurer has directed its network pharmacies to no longer accept co-pay coupons for certain specialty drugs the insurer identified. In addition, in November 2013, the CMS issued guidance to the issuers of qualified health plans sold through the ACA's marketplaces encouraging such plans to reject patient cost-sharing support from third parties and indicating that the CMS intends to monitor the provision of such support and may take regulatory action to limit it in the future. The CMS subsequently issued a rule requiring individual market qualified health plans to accept third-party premium and cost-sharing payments from certain government-related entities. In September 2014, the OIG of the HHS issued a Special Advisory Bulletin warning manufacturers that they may be subject to sanctions under the federal Anti-Kickback Statute and/or civil monetary penalty laws if they do not take appropriate steps to exclude Part D beneficiaries from using co-pay coupons. Accordingly, companies exclude these Part D beneficiaries from using co-pay coupons. It is possible that changes in insurer policies regarding co-pay coupons and/or the introduction and enactment of new legislation or regulatory action could restrict or otherwise negatively affect these patient support programs, which could result in fewer patients using affected products, and therefore could have a material adverse effect on our sales, business, and financial condition.

Third party patient assistance programs that receive financial support from companies have become the subject of enhanced government and regulatory scrutiny. The OIG has established guidelines that suggest that it is lawful for pharmaceutical manufacturers to make donations to charitable organizations who provide co-pay assistance to Medicare patients, provided that such organizations, among other things, are bona fide charities, are entirely independent of and not controlled by the manufacturer, provide aid to applicants on a first-come basis according to consistent financial criteria and do not link aid to use of a donor's product. However, donations to patient assistance programs have received some negative publicity and have been the subject of multiple government enforcement actions, related to allegations regarding their use to promote branded pharmaceutical products over other less costly alternatives. Specifically, in recent years, there have been multiple settlements resulting out of government claims challenging the legality of their patient assistance programs under a variety of federal and state laws. It is possible that we may make grants to independent charitable foundations that help financially needy patients with their premium, co-pay, and co-insurance obligations. If we choose to do so, and if we or our vendors or donation recipients are deemed to fail to comply with relevant laws, regulations or evolving government guidance in the operation of these programs, we could be subject to damages, fines, penalties, or other criminal, civil, or administrative sanctions or enforcement actions. We cannot ensure that our compliance controls, policies, and procedures will be sufficient to protect against acts of our employees, business partners, or vendors that may violate the laws or regulations of the jurisdictions in which we operate. Regardless of whether we have complied with the law, a government investigation could impact our business practices, harm our reputation, divert the attention of management, increase our expenses, and reduce the availability of foundation support for our patients who need assistance.

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On December 2, 2020, the United States Department of Heath and Human Service, or HHS, published a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Part D, either directly or through pharmacy benefit managers (PBMs), unless the price reduction is required by law. The rule also creates a new safe harbor for price reductions reflected at the point-of-sale, as well as a safe harbor for certain fixed fee arrangements between PBMs and manufacturers. Implementation of this change and new safe harbors for point-of-sale reductions in price for prescription pharmaceutical products and PBM service fees are currently under review by the current U.S. presidential administration and may be amended or repealed. Further, on December 31, 2020, CMS published a new rule, effective January 1, 2023, requiring manufacturers to ensure the full value of co-pay assistance is passed on to the patient or these dollars will count toward the Average Manufacturer Price and Best Price calculation of the drug. On May 21, 2021, PhRMA sued the HHS in the U.S. District Court for the District of Columbia, to stop the implementation of the rule claiming that the rule contradicts federal law surrounding Medicaid rebates. It is unclear how the outcome of this litigation will affect the rule. On May 17, 2022, the U.S. District Court for the District of Columbia granted PhRMA’smotion for summary judgement invalidating the Accumulator Rule. We cannot predict how the implementation of and any further changes to this rule will affect our business. Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and the current U.S. presidential administration may reverse or otherwise change these measures, both the current U.S. presidential administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs.

Law enforcement authorities are increasingly focused on enforcing fraud and abuse laws, and it is possible that some of our practices may be challenged under these laws. Efforts to ensure that our current and future business arrangements with third parties, and our business generally, will comply with applicable healthcare laws and regulations will involve substantial costs. If our operations, including our arrangements with physicians and other healthcare providers, are found to be in violation of any of such laws or any other governmental regulations that apply to us, we may be subject to penalties, including, without limitation, administrative, criminal and/or civil penalties, damages, fines, disgorgement, reputational harm, imprisonment, the exclusion or suspension from federal and state healthcare programs such as Medicare and Medicaid and debarment from contracting with the United States government, and/or the curtailment or restructuring of our operations, as well as additional reporting obligations and oversight if we become subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws. If any of the physicians or other healthcare providers or entities with whom we expect to do business are found to be not in compliance with applicable laws, they may be subject to similar penalties.

The risk of our being found in violation of these laws is increased by the fact that many of these laws have not been fully interpreted by the regulatory authorities or the courts, and their provisions are open to a variety of interpretations. Any action against us for violation of these laws, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management’s attention from the operation of our business. The shifting compliance environment and the need to build and maintain a robust system to comply with multiple jurisdictions with different compliance and reporting requirements increases the possibility that a healthcare company may violate one or more of the requirements. Efforts to ensure that our business arrangements with third parties will comply with applicable healthcare laws and regulations will involve substantial cost.

Data Privacy and Security Laws

We may also be subject to data privacy and security laws in the United States and various jurisdictions around the world in which we operate or from which we collect or otherwise process personally identifiable information (“personal information”). In the United States, HIPAA, imposes privacy, security and breach reporting obligations with respect to individually identifiable health information upon “covered entities” (health plans, health care clearinghouses and certain health care providers), and their respective business associates, individuals or entities that create, received, maintain or transmit protected health information in connection with providing a service for or on behalf of a covered entity. HIPAA mandates the reporting of certain breaches of personal information to HHS, affected individuals and if the breach is large enough, the media. Entities that are found to be in violation of HIPAA as the result of a breach of unsecured protected health information, a complaint about privacy practices or an audit by HHS, may be subject to significant civil, criminal and administrative fines and penalties and/or additional reporting and oversight obligations if required to enter into a resolution agreement and corrective action plan with HHS to settle allegations of HIPAA non-compliance. Even when HIPAA does not apply, according to the Federal Trade Commission or the FTC, failing to take appropriate steps to keep consumers’ personal information secure constitutes unfair acts or practices in or affecting commerce in violation of Section 5(a) of the Federal Trade Commission Act, or the FTCA, 15 U.S.C § 45(a). The FTC expects a company’s data security measures to be reasonable and appropriate in light of the sensitivity and volume of consumer information it holds, the size and complexity of its business, and the cost of available tools to improve security and reduce vulnerabilities. Individually identifiable health information is considered sensitive data that merits stronger safeguards.

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In addition, certain states govern the privacy and security of health information and/or other personally identifiable information, some of which are more stringent than HIPAA and many of which differ from each other in significant ways and may not have the same effect, thus complicating compliance efforts. Failure to comply with these laws, where applicable, can result in the imposition of significant civil and/or criminal penalties and private litigation. For example, California recently enacted the CCPA, which creates new individual privacy rights for California consumers (as defined in the law) and places increased privacy and security obligations on entities handling personal data of consumers or households. The CCPA requires covered companies to provide certain disclosures to consumers about its data collection, use and sharing practices, and to provide affected California residents with ways to opt-out of certain sales or transfers of personal information. The CCPA went into effect on January 1, 2020, and the California Attorney General commenced enforcement actions against violators beginning July 1, 2020. While there is currently an exception for protected health information that is subject to HIPAA and/or that is collected, used, or disclosed in clinical trial research, as currently written, the CCPA may still impact our business activities. The uncertainty and enforcement surrounding the implementation of CCPA exemplifies the vulnerability of our business to the evolving regulatory environment related to personal data and protected health information. The CCPA may increase our compliance costs and potential liability. Some observers have noted that the CCPA could mark the beginning of a trend toward more stringent privacy legislation in the U.S., which could increase our potential liability and adversely affect our business.

Additionally, a California ballot initiative, the California Privacy Rights Act, or “CPRA,” was passed in November 2020 and became effective starting on January 1, 2023. The CPRA imposes additional obligations on companies covered by the legislation and significantly modifies the CCPA, including by expanding consumers’ rights with respect to certain sensitive personal information. The CPRA also creates a new state agency that will be vested with authority to implement and enforce the CCPA and the CPRA. The effects of the CCPA, as modified by the CPRA are potentially significant and may require us to modify our data collection or processing practices and policies and to incur substantial costs and expenses in an effort to comply and increase our potential exposure to regulatory enforcement and/or litigation.

Certain other states, including Colorado, Connecticut, Utah and Virginia have passed laws comprehensive consumer privacy laws that impose similar privacy obligations and we also expect anticipate that more states to may enact legislation similar to the CCPA. The CCPA has prompted a number of proposals for new federal and state-level privacy legislation. Such proposed legislation, if enacted, may add additional complexity, variation in requirements, restrictions and potential legal risk, require additional investment of resources in compliance programs, impact strategies and the availability of previously useful data and could result in increased compliance costs and/or changes in business practices and policies.

The collection, use, storage, disclosure, transfer, or other processing of personal information regarding individuals in the European Economic Area, or EEA, including personal health data, is subject to the EU GDPR, which became effective on May 25, 2018. Following the United Kingdom's ("UK") withdrawal from the EU ("Brexit"), the EU GDPR has been incorporated into UK laws ("UK GDPR" and together with the EU GDPR, "GDPR"). The GDPR is wide-ranging in scope and imposes numerous requirements on companies that process personal data, including requirements relating to processing health and other sensitive data, obtaining consent of the individuals to whom the personal data relates, providing information to individuals regarding data processing activities, implementing safeguards to protect the security and confidentiality of personal data, providing notification of data breaches, and taking certain measures when engaging third-party processors. The GDPR also imposes strict rules on the transfer of personal data to countries outside the European Union and the UK, including the United States, and permits data protection authorities to impose large penalties for violations of the GDPR, including potential fines of up to €20 million (£17.5 million) or 4% of annual global revenues, whichever is greater. The GDPR also confers a private right of action on data subjects and consumer associations to lodge complaints with supervisory authorities, seek judicial remedies, and obtain compensation for damages resulting from violations of the GDPR. Despite Brexit, the EU and UK GDPR remain largelyaligned.Currently, the most impactful point of divergence relates to transfer mechanisms (i.e., the ability for EU/UK companies to transferpersonal information to third countries, including the United States), because it requires us to implement a variety of different contractual clauses approved by EU or UK regulators. This complexity and the additional contractual burden increases our overall risk exposure. There may be further divergence in the future, including with regard to administrative burdens. The UK has announced plans to reform the country’s data protection legal framework in its Data Reform Bill, which will introduce significant divergence from the EU GDPR. Compliance with the EU GDPR and UK GDPR is a rigorous and time-intensive process that may increase our cost of doing business or require us to change our business practices, and despite those efforts, there is a risk that we may be subject to fines and penalties, litigation, and reputational harm in connection with our European or UK activities.

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In addition, various jurisdictions around the world continue to propose new laws that regulate the privacy and/or security of certain types of personal data. Complying with these laws, if enacted, would require significant resources and leave us vulnerable to possible fines and penalties if we are unable to comply. The regulatory framework governing the collection, processing, storage, use and sharing of certain information is rapidly evolving and is likely to continue to be subject to uncertainty and varying interpretations. It is possible that these laws may be interpreted and applied in a manner that is inconsistent with our existing data management practices or the features of our services and platform capabilities. Any failure or perceived failure by us, or any third parties with which we do business, to comply with our posted privacy policies, evolving laws, rules and regulations, industry standards, or contractual obligations to which we or such third parties are or may become subject, may result in actions or other claims against us by governmental entities or private actors, the expenditure of substantial costs, time and other resources or the incurrence of significant fines, penalties or other liabilities. In addition, any such action, particularly to the extent we were found to be guilty of violations or otherwise liable for damages, would damage our reputation and adversely affect our business, financial condition and results of operations.

Healthcare Reform

In the United States and some foreign jurisdictions, there have been, and likely will continue to be, a number of legislative and regulatory changes and proposed changes regarding the healthcare system directed at broadening the availability of healthcare, improving the quality of healthcare, and containing or lowering the cost of healthcare. For example, in March 2010, the ACA, was enacted which includes changes to the coverage and payment for products under government health care programs. Among other things, the ACA:

Since its enactment, there have been judicial, Congressional and executive challenges to certain aspects of the ACA. On June 17, 2021, the U.S. Supreme Court dismissed the most recent judicial challenge to the ACA brought by several states without specifically ruling on the constitutionality of the ACA. Prior to the Supreme Court’s decision, President Biden issued an executive order to initiate a special enrollment period from February 15, 2021, through August 15, 2021, for purposes of obtaining health insurance coverage through the ACA marketplace. The executive order also instructed certain governmental agencies to review and reconsider their existing policies and rules that limit access to healthcare, including among others, reexamining Medicaid demonstration projects and waiver programs that include work requirements, and policies that create unnecessary barriers to obtaining access to health insurance coverage through Medicaid or the ACA. It is unclear how other healthcare reform measures of the Biden administration or other efforts, if any, to challenge, repeal or replace the ACA will impact our business.

Prior to the Biden administration, on October 13, 2017, former President Trump signed an Executive Order terminating the cost-sharing subsidies that reimburse insurers under the ACA. The former Trump administration concluded that cost-sharing reduction, or CSR, payments to insurance companies required under the ACA have not received necessary appropriations from Congress and announced that it will discontinue these payments immediately until those appropriations are made. Several state Attorneys General filed suit to stop the administration from terminating the subsidies, but their request for a restraining order was denied by a federal judge in California on October 25, 2017. On August 14, 2020, the U.S. Court of Appeals for the Federal Circuit ruled in two separate cases that the federal government is liable for the full amount of unpaid CSRs for the years preceding and including 2017. For CSR claims made by health insurance companies for years 2018 and later, further litigation will be required to determine the amounts due, if any. Further, on June 14, 2018, the U.S. Court of Appeals for the Federal Circuit ruled that the federal government was not required to pay more than $12 billion in ACA risk corridor payments to third-party payors who argued the payments were owed to them. On April 27, 2020, the United States Supreme Court reversed the U.S. Court of Appeals for the Federal Circuit's decision and remanded the case to the U.S. Court of Federal Claims, concluding the government has an obligation to pay these risk corridor payments under the relevant formula. It is unclear what impact these rulings will have on our business.

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On December 20, 2019, former President Trump signed into law the Further Consolidated Appropriations Act (H.R. 1865), which repeals the Cadillac tax, the health insurance provider tax, and the medical device excise tax. It is impossible to determine whether similar taxes could be instated in the future.

Other legislative changes have been proposed and adopted in the United States since the Affordable Care Act was enacted. The Budget Control Act of 2011, among other things, included aggregate reductions to Medicare payments to providers of 2% per fiscal year. These reductions went into effect on April 1, 2013, and, due to legislation amendments to the statute, including the Bipartisan Budget Act of 2018, or BBA, will stay in effect through 2030, unless additional Congressional action is taken. However, the Medicare sequester reductions under the Budget Control Act have been suspended from May 1, 2020, through March 31, 2022, due to the COVID-19 pandemic. Following the temporary suspension, a 1% payment reduction began April 1, 2022 and remained through June 30, 2022. The 2% payment reduction resumed on July 1, 2022. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law, which, among other things, further reduced Medicare payments to several types of providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. In December 2018, CMS published a final rule permitting further collections and payments to and from certain ACA qualified health plans and health insurance issuers under the ACA risk adjustment program in response to the outcome of the federal district court litigation regarding the method CMS uses to determine this risk adjustment. Since then, the ACA risk adjustment program payment parameters have been updated annually. In addition, CMS published a final rule that would give states greater flexibility, as of 2020, in setting benchmarks for insurers in the individual and small group marketplaces, which may have the effect of relaxing the essential health benefits required under the ACA for plans sold through such marketplaces. Further, on May 30, 2018, the Right to Try Act was signed into law. The law, among other things, provides a federal framework for certain patients to request access to certain investigational new drug products that have completed a Phase 1 clinical trial and that are undergoing investigation for FDA approval. There is no obligation for a pharmaceutical manufacturer to make its drug products available to eligible patients as a result of the Right to Try Act.

Additionally, there has been increasing legislative and enforcement interest in the United States with respect to specialty drug pricing practices. Specifically, there have been several recent U.S. Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, reduce the cost of prescription drugs under Medicare, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs.

Legislative and regulatory proposals have been made to expand post-approval requirements and restrict sales and promotional activities for pharmaceutical products. We cannot be sure whether additional legislative changes will be enacted, or whether the FDA or foreign regulations, guidance or interpretations will be changed, or what the impact of these changes on the regulatory approvals of our product candidates, if any, may be. In the U.S., the European Union and other potentially significant markets for our product candidates, government authorities and third-party payors are increasingly attempting to limit or regulate the price of medical products and services, particularly for new and innovative products and therapies, which has resulted in lower average selling prices for certain products in certain markets. For example, in the U.S., there have been several recent Congressional inquiries and proposed and enacted federal and state legislation designed to, among other things, bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drugs. At a federal level, President Biden signed an Executive Order on July 9, 2021, affirming the administration’s policy to (i) support legislative reforms that would lower the prices of prescription drug and biologics, including by allowing Medicare to negotiate drug prices, by imposing inflation caps, and, by supporting the development and market entry of lower-cost generic drugs and biosimilars; and (ii) support the enactment of a public health insurance option. Among other things, the Executive Order also directs HHS to provide a report on actions to combat excessive pricing of prescription drugs, enhance the domestic drug supply chain, reduce the price that the Federal government pays for drugs, and address price gouging in the industry; and directs the FDA to work with states and Indian Tribes that propose to develop section 804 Importation Programs in accordance with the Medicare Prescription Drug, Improvement, and Modernization Act of 2003, and the FDA’s implementing regulations. FDA released such implementing regulations on September 24, 2020, which went into effect on November 30, 2020, providing guidance for states to build and submit importation plans for drugs from Canada. On September 25, 2020, CMS stated drugs imported by states under this rule will not be eligible for federal rebates under Section 1927 of the Social Security Act and manufacturers would not report these drugs for “best price” or Average Manufacturer Price purposes. Since these drugs are not considered covered outpatient drugs, CMS further stated it will not publish a National Average Drug Acquisition Cost for these drugs. If implemented, importation of drugs from Canada may materially and adversely affect the price we receive for any of our product candidates. Further on November 20, 2020, CMS issued an Interim Final Rule implementing the Most Favored Nation, or MFN, Model under which Medicare Part B reimbursement rates would have been calculated for certain drugs and biologicals based on the lowest price drug manufacturers receive in Organization for Economic Cooperation and Development countries with a similar gross domestic product per capita. However, on August 6, 2021, CMS announced a proposed rule to rescind the Most Favored Nations rule. Additionally, on November 30, 2020, HHS published a regulation removing safe harbor protection for price reductions from pharmaceutical manufacturers to plan sponsors under Part D, either directly or through pharmacy benefit managers, unless the price reduction is required by law. The rule also creates a new safe harbor for price reductions reflected at the point-of-sale, as well as a safe harbor for certain fixed fee arrangements between pharmacy benefit managers and manufacturers. Pursuant to court order, the removal and addition of the aforementioned safe harbors were delayed and recent legislation imposed a moratorium on implementation of the

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rule until January 1, 2026. This deadline was pushed back to January 1, 2027 by the Bipartisan Safer Communities Act. The Inflation Reduction Act of 2022, or the IRA, further delayed implementation of this rule to January 1, 2032. Although a number of these and other proposed measures may require authorization through additional legislation to become effective, and the Biden administration may reverse or otherwise change these measures, both the Biden administration and Congress have indicated that they will continue to seek new legislative measures to control drug costs.

In August 2022, the IRA was signed into law. The IRA includes several provisions that will impact our business to varying degrees, including provisions that create a $2,000 out-of-pocket cap for Medicare Part D beneficiaries, impose new manufacturer financial liability on all drugs in Medicare Part D, allow the U.S. government to negotiate Medicare Part B and Part D pricing for certain high-cost drugs and biologics without generic or biosimilar competition, require companies to pay rebates to Medicare for drug prices that increase faster than inflation, and delay the rebate rule that would require pass through of pharmacy benefit manager rebates to beneficiaries. The effect of IRA on our business and the healthcare industry in general is not yet known. We expect that additional U.S. federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that the U.S. Federal Government will pay for healthcare drugs and services, which could result in reduced demand for our drug candidates or additional pricing pressures.

At the state level, legislatures are increasingly passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, financial condition, results of operations and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our drugs or put pressure on our drug pricing, which could negatively affect our business, financial condition, results of operations and prospects.

Human Capital

As of December 31, 2022, we had 106 full-time employees, including 20 with Ph.D. or M.D. degrees, and 80 who are engaged in research and development activities. None of our employees are represented by labor unions or covered by collective bargaining agreements. We consider our relationship with our employees to be good.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and new employees, advisors and consultants. The principal purposes of our equity incentive plans are to attract, retain and reward personnel through the granting of equity-based compensation awards in order to increase shareholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

Available Information

Our Internet address is www. allovir.com. Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, including exhibits, proxy and information statements and amendments to those reports filed or furnished pursuant to Sections 13(a), 14, and 15(d) of the Securities Exchange Act of 1934, as amended, or the Exchange Act, are available through the “Investors” portion of our website free of charge as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. Information on our website is not part of this Annual Report on Form 10-K or any of our other securities filings unless specifically incorporated herein by reference. In addition, our filings with the SEC may be accessed through the SEC’s Interactive Data Electronic Applications system at http://www.sec.gov. All statements made in any of our securities filings, including all forward-looking statements or information, are made as of the date of the document in which the statement is included, and we do not assume or undertake any obligation to update any of those statements or documents unless we are required to do so by law.

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Item 1A. Risk Factors.

Our business is subject to numerous risks. You should consider carefully the risks and uncertainties described below, in addition to other information contained in this Annual Report on Form 10-K, as well as our other public filings with the Securities and Exchange Commission, or the SEC. Any of the following risks could have a material adverse effect on our business, financial condition, results of operations and growth prospects and could cause the trading price of our common stock to decline.

Risks Related to Current Novel Coronavirus (COVID-19) Pandemic

Our business could be adversely affected by the effects of health epidemics, including the ongoing COVID-19 pandemic, in regions where third parties for which we rely, including CROs or CMOs, have significant research, development or manufacturing facilities, concentrations of clinical trial sites or other business operations, causing disruption in supplies and services.

Our business could be adversely affected by health epidemics in regions where third parties for which we rely, as in contract research organizations, or CROs, or contract manufacturing organizations, or CMOs, have concentrations of clinical trial sites or other business operations, and could cause significant disruption in the operations of third-party manufacturers and CROs upon whom we rely. On January 30, 2020, the World Health Organization, or WHO, announced a global health emergency because of SARS-CoV-2, a new strain of novel coronavirus originating in Wuhan, China, and the risks to the international community as the virus spread globally beyond its point of origin. In March 2020, the WHO declared the COVID-19 outbreak a pandemic, which continues to spread throughout the world. The spread of this pandemic has caused significant volatility and uncertainty in U.S. and international markets. This could result in an economic downturn and may disrupt our business and delay our clinical programs and timelines.

Quarantines, shelter-in-place and similar government orders, or the perception that such orders, shutdowns or other restrictions on the conduct of business operations could occur, related to COVID-19 or other infectious diseases could impact personnel at third-party manufacturing facilities in the United States and other countries, or the availability or cost of materials, which would disrupt our supply chain. Any manufacturing supply interruption of materials could adversely affect our ability to conduct ongoing and future research and manufacturing activities.

In addition, our clinical trials may be affected by the COVID-19 pandemic, including the emergence of new variants. Clinical site initiation and patient enrollment may be delayed due to prioritization of healthcare system resources toward the COVID-19 pandemic. Some patients may not be able to comply with clinical trial protocols if quarantines impede patient movement or interrupt healthcare services. Similarly, the ability to recruit and retain patients and principal investigators and site staff who, as healthcare providers, may have heightened exposure to COVID-19 and adversely impact our clinical trial operations.

The spread of COVID-19, which has caused a broad impact globally, may materially affect us economically. While the potential economic impact brought by, and the duration of, COVID-19 may be difficult to assess or predict, a widespread pandemic could result in significant disruption of global financial markets, reducing our ability to access capital, which could in the future negatively affect our liquidity. In addition, a recession or market correction resulting from the spread of COVID-19 could materially affect our business and the value of our common stock.

Since the beginning of the COVID-19 pandemic, several vaccines for COVID-19 have received Emergency Use Authorization by the U.S. Food and Drug Administration, or the FDA, and a number of those later received marketing approval. Additional vaccines may be authorized or approved in the future. The resultant demand for vaccines and potential for manufacturing facilities and materials to be commandeered under the Defense Production Act of 1950, or equivalent foreign legislation, may make it more difficult to obtain materials or manufacturing slots for the products needed for our clinical trials, which could lead to delays in these trials.

The global pandemic of COVID-19 continues to rapidly evolve. The ultimate impact of the COVID-19 pandemic or a similar health epidemic is highly uncertain and subject to change. We do not yet know the full extent of potential delays or impacts on our business, our clinical trials, healthcare systems or the global economy as a whole. However, these effects could have a material impact on our operations, and we will continue to monitor the COVID-19 situation closely.

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Risks Related to the Clinical Development, Regulatory Review and Approval of Our Product Candidates

Risks Related to Clinical Development

We are early in our development efforts and have only a small number of product candidates in clinical development. All of our other product candidates are still in preclinical development. If we or our collaborators are unable to successfully develop and commercialize product candidates or experience significant delays in doing so, our business may be materially harmed.

We are early in our development efforts, and only a small number of our product candidates are in or are entering into clinical development. The majority of our product candidates are currently in preclinical development. We have invested substantial resources in identifying and developing potential product candidates, conducting preclinical studies and clinical trials and developing an efficient and scalable manufacturing process for our product candidates. Our ability to generate revenues, which we do not expect will occur for several years, if ever, will depend heavily on the successful development and eventual commercialization of our product candidates. The success of our product candidates and our ability to generate revenues and achieve profitability will depend on many factors, including the following:

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If we do not achieve one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully develop and commercialize our product candidates, which could materially harm our business. Our revenues for any of our product candidates for which regulatory approval is obtained will be dependent, in part, upon the size of the markets in the territories for which we gain regulatory approval, the accepted price for the product, the ability to obtain reimbursement at any price, and whether we own the commercial rights for such territory. If the addressable patient population in such territory is not as significant as we estimate, the indication approved by regulatory authorities is narrower than we expect, or the reasonably accepted population for treatment is narrowed by competition, physician choice or treatment guidelines, we may not generate significant revenues from sales of our products, even if approved. In addition, we anticipate incurring significant costs associated with commercializing any approved product candidate. As a result, even if we generate revenues, we may not become profitable and may need to obtain additional funding to continue operations. If we fail to become profitable or are unable to sustain profitability on a continuing basis, then we may be unable to continue our operations as planned and may be forced to reduce or discontinue our operations. In addition, regulators may determine that our financial relationships with our principal investigators, some of whom receive compensation as consultants, in a perceived or actual conflict of interest, may have affected the interpretation of a study, the integrity of the data generated at the applicable clinical trial site or the utility of the clinical trial.

Our future success is dependent on the regulatory approval of our product candidates. The regulatory approval processes of the FDA and comparable foreign authorities are lengthy, time consuming and inherently unpredictable, and if we are ultimately unable to obtain regulatory approval for our product candidates, our business will be substantially harmed.

We have not obtained regulatory approval for any of our product candidates, including our clinical-stage product candidates, posoleucel and, ALVR106. Our business is substantially dependent on our ability to obtain regulatory approval for, and, if approved, to successfully commercialize our product candidates in a timely manner.

We cannot commercialize product candidates in the United States without first obtaining regulatory approval from the FDA; similarly, we cannot commercialize product candidates outside of the United States without obtaining regulatory approval from comparable foreign regulatory authorities. Before obtaining regulatory approvals for the commercial sale of any product candidate for a target indication, we must demonstrate with substantial evidence gathered in preclinical studies and clinical trials, that the product candidate is safe and effective for use for that target indication and that the manufacturing facilities, processes and controls are adequate with respect to such product candidate to assure safety, purity and potency.

The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable but typically takes many years following the commencement of preclinical studies and clinical trials and depends upon numerous factors, including the study designs and substantial discretion of the regulatory authorities. In addition, approval policies, regulations, or the type and amount of clinical data necessary to gain approval may change during the course of a product candidate’s clinical development and may vary among jurisdictions. We have not obtained regulatory approval for any product candidate and it is possible that none of our existing product candidates or any future product candidates will ever obtain regulatory approval.

Our product candidates could fail to receive regulatory approval from the FDA or a comparable foreign regulatory authority for many reasons, including:

This lengthy approval process as well as the unpredictability of future clinical trial results may result in our failing to obtain regulatory approval to market our product candidates, which would significantly harm our business, results of operations and prospects. The FDA or a comparable foreign regulatory authority may require more information, including additional preclinical or clinical data to support approval, which may delay or prevent approval and our commercialization plans, or we may decide to abandon the development program. If we were to obtain approval, regulatory authorities may approve any of our product candidates for fewer or more limited

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indications than we request (including failing to approve the most commercially promising indications), may grant approval contingent on the performance of costly post-marketing clinical studies, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable for the successful commercialization of that product candidate.

In addition, the clinical trial requirements of the FDA, the European Medicines Agency, or the EMA, and other regulatory agencies and the criteria these regulators use to determine the safety and efficacy of a product candidate are determined according to the type, complexity, novelty and intended use and market of the potential products. The regulatory approval process for novel product candidates, such as our novel multi-VST-cell therapy, can be more complex and consequently more expensive and take longer than for other, better known or extensively studied pharmaceutical or other product candidates. There are currently no FDA approved cell-based therapies for the treatment of viral diseases, including those that our product candidates are designed to target. Moreover, our product candidates may not perform successfully in clinical trials or may be associated with adverse events.

Risks Related to the Industry

Disruptions at the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved, or commercialized in a timely manner or at all, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, statutory, regulatory, and policy changes, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and other events that may otherwise affect the FDA’s ability to perform routine functions. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the SEC and other government agencies on which our operations may rely, including those that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable. Disruptions at the FDA and other agencies may also slow the time necessary for biological products, or biologics, or modifications to approved biologics to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations. For example, over the last several years, including for 35 days beginning on December 22, 2018, the U.S. government has shut down several times and certain regulatory agencies, such as the FDA, have had to furlough critical FDA employees and stop critical activities.

Since March 2020 when foreign and domestic inspections of facilities were largely placed on hold, the FDA has been working to resume routine surveillance, bioresearch monitoring and pre-approval inspections on a prioritized basis. Should the FDA determine that an inspection is necessary for approval and an inspection cannot be completed during the review cycle due to restrictions on travel, and the FDA does not determine a remote interactive evaluation to be adequate, the agency has stated that it generally intends to issue, depending on the circumstances, a complete response letter or defer action on the application until an inspection can be completed. During the COVID-19 public health emergency, a number of companies announced receipt of complete response letters due to the FDA's inability to complete required inspections for their applications. Regulatory authorities outside the U.S. may adopt similar restrictions or other policy measures in response to the ongoing COVID-19 pandemic and may experience delays in their regulatory activities.

The regulatory landscape that applies to gene and cell therapy product candidates is rigorous, complex, uncertain and subject to change. Our single- and multi-VST cell therapy product candidates represent new therapeutic approaches that could result in heightened regulatory scrutiny, delays in clinical development or delays in or our ability to achieve regulatory approval, if at all, and commercialization or payor coverage and reimbursement of our product candidates, if approved.

Our future success is dependent on our single- and multi-VST cell therapy approach. Because these programs, particularly our pipeline of allogeneic T cell product candidates that are bioengineered from donors, represent a unique approach to immunotherapy for the treatment of virus-infected cells in order to restore T cell immunity, developing and commercializing our product candidates subjects us to a number of challenges, including:

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Regulatory requirements governing the development of gene therapy products have changed frequently and may continue to change in the future. The FDA has established the Office of Therapeutic Products, or OTP, within the CBER, to consolidate the review of gene therapy and related products, and to advise the CBER on its review. In addition, under guidelines issued by the National Institutes of Health, or NIH, gene therapy clinical trials are also subject to review and oversight by an institutional biosafety committee, or IBC, a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. Before a clinical trial can begin at any institution, that institution’s institutional review board, or IRB, and its IBC assesses the safety of the research and identifies any potential risk to public health or the environment. While the NIH guidelines are not mandatory unless the research in question is being conducted at or sponsored by institutions receiving NIH funding of recombinant or synthetic nucleic acid molecule research, many companies and other institutions not otherwise subject to the NIH Guidelines voluntarily follow them. Moreover, serious adverse events or developments in clinical trials of gene therapy product candidates conducted by others may cause the FDA or other regulatory bodies to initiate a clinical hold on our clinical trials or otherwise change the requirements for approval of any of our product candidates. Although the FDA decides whether individual cell and gene therapy protocols may proceed, the review process and determinations of other reviewing bodies can impede or delay the initiation of a clinical trial, even if the FDA has reviewed the trial and approved its initiation.

Adverse developments in preclinical studies or clinical trials conducted by others in the field of gene therapy and gene regulation products may cause the FDA, the EMA, and other regulatory bodies to amend the requirements for approval of any product candidates we may develop or limit the use of products utilizing gene regulation technologies, either of which could harm our business. In addition, the clinical trial requirements of the FDA, the EMA, and other regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty, and intended use and market of the potential products. The regulatory approval process for product candidates such as ours can be more expensive and take longer than for other, better known, or more extensively studied pharmaceutical or other product candidates. Further, as we are developing novel potential treatments for diseases in which there is little clinical experience with new endpoints and methodologies, there is heightened risk that the FDA, the EMA or other regulatory bodies may not consider the clinical trial endpoints to provide clinically meaningful results, and the resulting clinical data and results may be more difficult to analyze. The prospectively designed natural history studies with the same endpoints as our corresponding clinical trials may not be accepted by the FDA, EMA or other regulatory authorities. Regulatory agencies administering existing or future regulations or legislation may not allow production and marketing of products utilizing gene regulation technology in a timely manner or under technically or commercially feasible conditions. In addition, regulatory action or private litigation could result in expenses, delays, or other impediments to our research programs or the commercialization of resulting products.

We cannot be sure that the manufacturing processes used in connection with our T cell immunotherapy product candidates will yield a sufficient supply of satisfactory products that are safe, pure and potent, comparable to those T cells produced by our partners historically, scalable or profitable.

Moreover, actual or perceived safety issues, including adoption of new therapeutics or novel approaches to treatment, may adversely influence the willingness of subjects to participate in clinical trials, or if approved by applicable regulatory authorities, of physicians to

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subscribe to the novel treatment mechanics. The FDA or other applicable regulatory authorities may ask for specific post-market requirements, such as establishment of a Risk Evaluation and Mitigation Strategy, or REMS, and additional information informing benefits or risks of our products may emerge at any time prior to or after regulatory approval.

Physicians, hospitals and third-party payors are often slow to adopt new products, technologies and treatment practices that require additional upfront costs and training. Based on these and other factors, hospitals and payors may decide that the benefits of this new therapy do not or will not outweigh its costs.

Clinical drug development involves a lengthy and expensive process with an uncertain outcome, and the inability to successfully and timely conduct clinical trials and obtain regulatory approval for our product candidates would substantially harm our business.

Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process. Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy traits despite having progressed through preclinical studies and clinical trials.

We may experience delays in our ongoing or future clinical trials and we do not know whether clinical trials will begin or enroll subjects on time, will need to be redesigned or will be completed on schedule, if at all, such as on account of the COVID-19 pandemic and its impact at clinical trials sites or on the third-party service providers on whom we rely. In July 2020, the Investigational New Drug, or IND that Baylor College of Medicine, or BCM, submitted for ALVR109 was placed on clinical hold for safety concerns related to the quality of ancillary reagents unique to ALVR109. The FDA subsequently lifted this clinical hold and cleared the IND for ALVR109 but there can be no assurance that the FDA or comparable foreign regulatory authorities will not put clinical trials of any of our product candidates on clinical hold in the future. Any inability to commence or complete our planned clinical trials of our product candidates as a result of a clinical hold or otherwise, will delay or terminate our clinical development plans for our product candidates, may require us to incur additional clinical development costs and could impair our ability to ultimately obtain FDA approval for our product candidates. Clinical trials may be delayed, suspended or prematurely terminated for a variety of other reasons, such as:

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In addition, disruptions caused by the COVID-19 pandemic may increase the likelihood that we encounter such difficulties or delays in initiating, enrolling, conducting or completing our planned and ongoing clinical trials. We could also encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by a Data Safety Monitoring Board for such trial or by the FDA or comparable foreign regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. In addition, changes in regulatory requirements and policies may occur, and we may need to amend clinical trial protocols to comply with these changes. Amendments may require us to resubmit our clinical trial protocols to IRBs for reexamination, which may impact the costs, timing or successful completion of a clinical trial.

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We currently rely on CROs, other vendors and clinical trial sites to ensure the proper and timely conduct of our clinical trials, and while we have agreements governing their committed activities, we have limited influence over their actual performance.

Many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates. Additionally, we or our collaborators may experience unforeseen events during or resulting from clinical trials that could delay or prevent receipt of marketing approval for or commercialization of product candidates. If we or our collaborators are required to conduct additional clinical trials or other testing of product candidates beyond those that we or our collaborators currently contemplate, if we or our collaborators are unable to successfully complete clinical trials or other testing of such product candidates, if the results of these trials or tests are not positive or are only modestly positive or if there are safety concerns, we may:

If we experience delays or quality issues in the conduct, completion or termination of any clinical trial of our product candidates, the approval and commercial prospects of such product candidate will be harmed, and our ability to generate product revenues from such product candidate will be delayed. In addition, any delays in completing our clinical trials will increase our costs, slow down our product candidate development and approval process and jeopardize our ability to commence product sales and generate revenues. Any delays in completing our clinical trials for our product candidates may also decrease the period of commercial exclusivity. In addition, many of the factors that could cause a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of regulatory approval of our product candidates.

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The results of preclinical studies or earlier clinical trials are not necessarily predictive of future results. Our existing product candidates in clinical trials, and any other product candidate we advance into clinical trials, may not have favorable results in later clinical trials or receive regulatory approval.

Success in preclinical studies and early clinical trials does not ensure that later clinical trials, including our Phase 3 pivotal and Phase 2 proof-of-concept clinical trials of posoleucel, will generate adequate data to demonstrate the efficacy and safety of any of our product candidates. Likewise, a number of companies in the pharmaceutical and biotechnology industries, including those with greater resources and experience than us, have suffered significant setbacks in clinical trials, even after seeing promising results in earlier preclinical studies or clinical trials. Despite the results reported in earlier preclinical studies or clinical trials for our product candidates, to date, results may not be replicated in subsequent trials, and we do not know whether the clinical trials we may conduct will demonstrate adequate efficacy and safety to result in regulatory approval to market posoleucel, ALVR106, ALVR109 or any future product candidates we develop from our allogeneic T cell immunotherapy platform. Additionally, certain of our clinical trial endpoints also may not be adequately powered in a particular subpopulation of our trial population. Additionally, all of our clinical trials to date have been open-label trials. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the investigational product candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from an open-label trial may not be predictive of future clinical trial results with any of our product candidates for which we include an open-label clinical trial when studied in a controlled environment with a placebo or active control.

Efficacy data from prospectively designed trial may differ significantly from those obtained from retrospective subgroup analyses. In addition, clinical data obtained from a clinical trial with an allogeneic product candidate such as posoleucel may not yield the same or better results as compared to an autologous product candidate. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that believed their product candidates performed satisfactorily in such studies nonetheless failed to obtain FDA, EMA or other necessary regulatory agency approval.

If later-stage clinical trials do not produce favorable results, our ability to achieve regulatory approval for any of our product candidates will be adversely impacted. Even if we believe that we have adequate data to support an application for regulatory approval to market any of our product candidates, no cell-based therapies for the treatment of viral diseases have been approved to date, and the FDA or other regulatory authorities may not agree and may require that we conduct additional clinical trials to support the regulatory approval of our product candidates. If we fail to obtain results in our planned and future preclinical and clinical activities and studies sufficient to meet the requirements of the relevant regulatory agencies, the development timeline and regulatory approval and commercialization prospects for any potential product candidate, and, correspondingly, our business and financial prospects, would be materially adversely affected.

Interim, “topline” or preliminary data from our clinical trials that we may announce or share with regulatory authorities from time to time may change as more patient data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may announce or share with regulatory authorities interim “topline” or preliminary data from our clinical trials, such as the June 2022 announcement of preliminary results for our Phase 2 posoleucel study for the treatment of BK virus, or BKV, in adult kidney transplant recipients, which is based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data related to the particular study or trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. As a result, the topline or preliminary results that we report may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. Preliminary or “topline” data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data we previously announced. As a result, interim, “topline,” and preliminary data should be viewed with caution until the final data are available. Adverse differences between preliminary, “topline,” or interim data and final data could impact the regulatory approval of, and significantly harm the prospects for any product candidate that is impacted by the applicable data.

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Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate or product and our business in general. In addition, the information we choose to publicly disclose regarding a particular study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is the material or otherwise appropriate information to include in our disclosure, and any information we determine not to disclose may ultimately be deemed significant with respect to future decisions, conclusions, views, activities or otherwise regarding a particular product candidate or our business. If the interim, “topline,” or preliminary data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for and commercialize our product candidates, our business, operating results, prospects or financial condition may be harmed.

Our product candidates, the methods used to deliver them or their dosage levels may cause undesirable side effects or have other properties that could delay or prevent their regulatory approval, limit the commercial profile of an approved label or result in significant negative consequences following any regulatory approval.

Undesirable side effects caused by our product candidates, their delivery methods or dosage levels could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or other comparable foreign regulatory authority. As a result of safety or toxicity issues that we may experience in our clinical trials, we may not receive approval to market any product candidates, which could prevent us from ever generating revenues or achieving profitability. Results of our trials could reveal an unacceptably high severity and incidence of side effects, or side effects outweighing the benefits of our product candidates. In such an event, our studies could be delayed, suspended or terminated and the FDA or comparable foreign regulatory authorities could order us to cease further development of or deny approval of our product candidates for any or all targeted indications. The drug-related side effects could affect patient recruitment or the ability of enrolled subjects to complete the trial or result in potential product liability claims. In addition, while we note the summary of safety findings we have gathered, to date, certain populations of patients receiving our product candidates may experience side effects in greater frequency or severity than others who may receive our product candidates and additional clinical research is planned to more fully understand the safety profile of our product candidates in our patient populations and indications of focus.

Additionally, if any of our product candidates receives regulatory approval, and we or others later identify undesirable side effects caused by such product, a number of potentially significant negative consequences could result. For example, the FDA could require us to adopt a REMS to ensure that the benefits of treatment with such product candidate outweigh the risks for each potential patient, which may include, among other things, a communication plan to health care practitioners, patient education, extensive patient monitoring or distribution systems and processes that are highly controlled, restrictive and more costly than what is typical for the industry. We or our collaborators may also be required to adopt a REMS or engage in similar actions, such as patient education, certification of health care professionals or specific monitoring, if we or others later identify undesirable side effects caused by any product that we develop alone or with collaborators. Other potentially significant negative consequences include that:

Any of these events could diminish the usage or otherwise limit the commercial success of our product candidates and prevent us from achieving or maintaining market acceptance of the affected product candidate, if approved by applicable regulatory authorities.

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We may not be able to obtain or maintain orphan drug designation to our product candidates, or to obtain and maintain the benefits associated with orphan drug designation, including the potential for market exclusivity.

Regulatory authorities in some jurisdictions, including the United States and Europe, may designate drugs for relatively small patient populations as orphan drugs. Under the Orphan Drug Act, the FDA may designate a product as an orphan drug if it is a drug intended to treat a rare disease or condition, which is generally defined as a patient population of fewer than 200,000 individuals annually in the United States. The FDA has granted orphan drug designation to posoleucel for the treatment of virus-associated hemorrhagic cystitis. In the European Union, the prevalence of the condition must not be more than 5 in 10,000. The EMA has granted posoleucel orphan drug designation to treatment in HCT. This designation covers the treatment of all viruses targeted by posoleucel in all HCT patients: BK virus, or BKV, cytomegalovirus, or CMV, adenovirus, or AdV, Epstein-Barr virus, or EBV, and human herpesvirus 6, or HHV-6. Orphan drug designation neither shortens the development time or regulatory review time of a drug nor gives the drug any advantage in the regulatory review or approval process.

If a product that has orphan drug designation from the FDA subsequently receives the first FDA approval for a particular active ingredient for the disease for which it has such designation, the product is entitled to orphan product exclusivity, which means that the FDA may not approve any other applications, including a BLA, to market the same biologic for the same indication, for seven years, except in limited circumstances such as a showing of clinical superiority to the product with orphan product exclusivity or if FDA finds that the holder of the orphan exclusivity has not shown that it can ensure the availability of sufficient quantities of the orphan product to meet the needs of patients with the disease or condition for which the product was designated. Even if we or our collaborators obtain orphan designation to a product candidate, we may not be the first to obtain marketing approval for any particular orphan indication due to the uncertainties associated with developing pharmaceutical products. The scope of exclusivity is limited to the scope of any approved indication, even if the scope of the orphan designation is broader than the approved indication. Additionally, exclusive marketing rights may be limited if we or our collaborators seek approval for an indication broader than the orphan designated indication and may be lost if the FDA later determines that the request for designation was materially defective or if the manufacturer is unable to assure sufficient quantities of the product to meet the needs of patients with the rare disease or condition. Further, even if a product obtains orphan drug exclusivity, that exclusivity may not effectively protect the product from competition because different drugs with different active moieties can be approved for the same condition. Even after an orphan drug is approved, the FDA can subsequently approve a product with the same active moiety for the same condition if the FDA concludes that the later product is safer, more effective, or makes a major contribution to patient care. Furthermore, the FDA can waive orphan exclusivity if we or our collaborators are unable to manufacture sufficient supply of the product. The FDA may further reevaluate the Orphan Drug Act and its regulations and policies. We do not know if, when, or how the FDA may change the orphan drug regulations and policies in the future, and it is uncertain how any changes might affect our business. Depending on what changes the FDA may make to its orphan drug regulations and policies, our business could be adversely impacted.

Similarly, in Europe, a medicinal product may receive orphan designation under Article 3 of Regulation (EC) 141/2000. This applies to products that are intended for a life-threatening or chronically debilitating condition and either (1) such condition affects no more than five in 10,000 persons in the EU when the application is made, or (2) the product, without the benefits derived from orphan status, would be unlikely to generate sufficient returns in the EU to justify the necessary investment. Moreover, in order to obtain orphan designation in the EU it is necessary to demonstrate that there exists no satisfactory method of diagnosis, prevention or treatment of such condition authorized for marketing in the EU or, if such a method exists, the product will be of significant benefit to those affected by the condition. In the EU, orphan medicinal products are eligible for financial incentives such as reduction of fees or fee waivers and applicants can benefit from specific regulatory assistance and scientific advice. Products receiving orphan designation in the EU can receive 10 years of market exclusivity, during which time no similar medicinal product for the same indication may be placed on the market. An orphan product can also obtain an additional two years of market exclusivity in the EU for pediatric studies. However, the 10-year market exclusivity may be reduced to six years if, at the end of the fifth year, it is established that the product no longer meets the criteria for orphan designation—for example, if the product is sufficiently profitable not to justify maintenance of market exclusivity. Additionally, marketing authorization may be granted to a similar product for the same indication at any time if:

If we or our collaborators do not receive or maintain orphan drug designation to product candidates for which we seek such designation, it could limit our ability to realize revenues from such product candidates.

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Risks Related to Our Business and Commercialization

Risks Related to Sales, Marketing and Competition

We face substantial competition, which may result in others discovering, developing or commercializing products before or more successfully than we do.

We face competition from numerous pharmaceutical and biotechnology enterprises, as well as from academic institutions, government agencies and private and public research institutions. Our commercial opportunities will be significantly impacted if our competitors develop and commercialize products that are safer, more effective, have fewer side effects, are less expensive or obtain more significant acceptance in the market than any product candidates that we develop. Additionally, our commercial opportunities will be significantly impacted if novel upstream products or changes in treatment protocols reduce the overall incidence or prevalence of diseases in our current or future target population. Competition could result in reduced sales and pricing pressure on our product candidates, if approved by applicable regulatory authorities. In addition, significant delays in the development of our product candidates could allow our competitors to bring products to market before us and impair any ability to commercialize our product candidates.

While there are currently no FDA- or EMA-approved drugs for our indications (other than for COVID-19), many of the approved or commonly used drugs and therapies for our current or future target diseases, including letermovir, cidofovir, ganciclovir, valganciclovir, foscarnet, oseltamivir, zanamivir, baloxavir, ribavirin, tenofovir, and entecavir, are well established and are widely accepted by physicians, patients and third-party payors. Some of these drugs are branded and subject to patent protection, and other drugs and nutritional supplements are available on a generic basis. Insurers and other third-party payors may encourage the use of generic products or specific branded products. We expect that, if any of our product candidates are approved, they will be priced at a significant premium over competitive generic products. Absent differentiated and compelling clinical evidence, pricing premiums may impede the adoption of our products over currently approved or commonly used therapies, which may adversely impact our business. In addition, many companies are developing new therapeutics, and we cannot predict what the standard of care will become as our products continue in clinical development.

Many of our competitors or potential competitors have significantly greater market presence, financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical studies, obtaining regulatory approvals and marketing approved products than we do, and as a result may have a competitive advantage over us. Smaller or early-stage companies may also prove to be significant competitors, including through collaborative arrangements or mergers with large and established companies. These third parties compete with us in recruiting and retaining qualified scientific, commercial and management personnel, establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies and technology licenses complementary to our programs or advantageous to our business.

As a result of these factors, these competitors may obtain regulatory approval of their products before we are able to, which will limit our ability to develop or commercialize our product candidates. Our competitors may also develop drugs that are safer, more effective, more widely used and cheaper than ours, and may also be more successful than us in manufacturing and marketing their products. These appreciable advantages could render our product candidates obsolete or noncompetitive before we can recover the expenses of development and commercialization.

If we are unable to establish sales and marketing capabilities or enter into agreements with third parties to market and sell our product candidates, we may be unable to generate any revenue.

We are at any early stage of establishing an organization that will be responsible for the sale, marketing and distribution of pharmaceutical products and the cost of establishing and maintaining such an organization may exceed the cost-effectiveness of doing so. In order to market any products that may be approved by the FDA and comparable foreign regulatory authorities, we must build our sales, marketing, managerial and other non-technical capabilities or make arrangements with third parties to perform these services. There are significant risks involved in building and managing a sales organization, including our ability to hire, retain and incentivize qualified individuals, generate sufficient sales leads, provide adequate training to sales and marketing personnel and effectively manage a geographically dispersed sales and marketing team. Any failure or delay in the development of our internal sales, marketing and distribution capabilities would adversely impact the commercialization of these products. We may be competing with many companies that currently have extensive and well-funded sales and marketing operations. Without a sufficiently scaled, appropriately timed and trained internal commercial organization or the support of a third party to perform sales and marketing functions, we may be unable to compete successfully against these more established companies.

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The incidence and prevalence of the target patient population for posoleucel are based on estimates and third-party sources. If the market opportunity for posoleucel or our other product candidates is smaller than we estimate or if any approval that we obtain is based on a narrower definition of the patient population, our revenue and ability to achieve profitability might be materially and adversely affected.

Periodically, we make estimates regarding the incidence and prevalence of target patient populations based on various third-party sources and internally generated analysis. These estimates may be inaccurate or based on imprecise data. For example, the total addressable market opportunity for posoleucel will depend on, among other things, acceptance of posoleucel by the medical community and patient access, drug pricing and reimbursement. The number of patients in the addressable markets may turn out to be lower than expected, patients may not be otherwise amenable to treatment with posoleucel, or new patients may become increasingly difficult to identify or gain access to, all of which may significantly harm our business, financial condition, results of operations and prospects.

We have received Regenerative Medicine Advanced Therapy, or RMAT, designation for the treatment of HC caused by BKV in adults and children following allogeneic HCT , adenovirus (AdV) infection following allogenic hematopoietic stem cell transplant (allo-HCT) and for the prevention of clinically significant infections and disease from six devastating viruses that commonly impact high-risk adult and pediatric patients following allo-HCT – adenovirus (AdV), BK virus (BKV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpes virus-6 (HHV-6) and JC virus (JCV), and received eligibility for the PRIME scheme from the EMA for the treatment of serious infections with BKV, CMV, AdV, EBV and HHV-6 in HCT patients, for posoleucel. These designations may not lead to a faster development or regulatory review or approval process, and will not increase the likelihood that such product candidates will receive marketing approval.

We have received RMAT designation from the FDA for posoleucel for the treatment of HC caused by BKV in adults and children following allo-HCT, for the treatment of AdV infection following allo-HCT, and for the prevention of clinically significant infections and end-organ diseases from AdV, BKV, CMV, EBV, HHV-6 and JCV in children and adults following allo-HCT. We have also received PRIME designation from the EMA for the treatment of serious infections with BKV, CMV, AdV, EBV and/or HHV-6 in HCT patients.

A company may request RMAT designation of its product candidate, which designation may be granted if the product meets the following criteria: (1) it is a cell therapy, therapeutic tissue engineering product, human cell and tissue product, or any combination product using such therapies or products, with limited exceptions; (2) it is intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition; and (3) preliminary clinical evidence indicates that the drug has the potential to address unmet medical needs for such a disease or condition. RMAT designation provides potential benefits that include more frequent meetings with FDA to discuss the development plan for the product candidate, and potential eligibility for rolling review and priority review. Products granted RMAT designation may also be eligible for accelerated approval on the basis of a surrogate or intermediate endpoint reasonably likely to predict long-term clinical benefit, or reliance upon data obtained from a meaningful number of sites, including through expansion to additional sites post-approval, if appropriate. RMAT-designated products that receive accelerated approval may, as appropriate, fulfill their post-approval requirements through the submission of clinical evidence, clinical studies, patient registries, or other sources of real world evidence (such as electronic health records); through the collection of larger confirmatory data sets; or via post-approval monitoring of all patients treated with such therapy prior to approval of the therapy. Under FDORA, the FDA is permitted to require, as appropriate, that a post-approval confirmatory study or studies be underway prior to approval or within a specified time period after the date of approval for a product granted accelerated approval. FDORA also requires sponsors to send updates to the FDA every 180 days on the status of such studies, including progress toward enrollment targets, and the FDA must promptly post this information publicly. FDORA also gives the FDA increased authority to withdraw approval of a drug or biologic granted accelerated approval on an expedited basis if the sponsor fails to conduct such studies in a timely manner, send the necessary updates to the FDA, or if such post-approval studies fail to verify the drug’s predicted clinical benefit. Under FDORA, the FDA is empowered to take action, such as issuing fines, against companies that fail to conduct with due diligence any post-approval confirmatory study or submit timely reports to the agency on their progress. In addition, for products being considered for accelerated approval, the FDA generally requires, unless otherwise informed by the agency, that all advertising and promotional materials intended for dissemination or publication within 120 days of marketing approval be submitted to the agency for review during the pre-approval review period. There can be no assurance that the FDA would allow any of the product candidates we may develop to proceed on an accelerated approval pathway, and even if the FDA did allow such pathway, there can be no assurance that such submission or application will be accepted or that any expedited development, review or approval will be granted on a timely basis, or at all. Moreover, even if we received accelerated approval, any post-approval studies required to confirm and verify clinical benefit may not show such benefit, which could lead to withdrawal of any approvals we have obtained. Receiving accelerated approval does not assure that the product’s accelerated approval will eventually be converted to a traditional approval.

PRIME is a scheme provided by the EMA to enhance support for the development of medicines that target an unmet medical need. To qualify for PRIME, product candidates require early clinical evidence that the therapy has the potential to offer a therapeutic advantage over existing treatments or benefits patients without treatment options. Among the benefits of PRIME are the appointment of a rapporteur to provide continuous support and help build knowledge ahead of a marketing authorization application, early dialogue and scientific advice at key development milestones, and the potential to qualify products for accelerated review earlier in the application process.

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RMAT designation and PRIME eligibility do not change the standards for product approval, and there is no assurance that any such designation or eligibility will result in expedited review or approval or that the approved indication will not be narrower than the indication covered by the RMAT designation or PRIME eligibility. Additionally, RMAT designation and access to PRIME can each be revoked if the criteria for eligibility cease to be met as clinical data emerges.

Even if our product candidates receive regulatory approval, we will still face extensive ongoing regulatory requirements and continued regulatory review, which may result in significant additional expense, and our products may still face future development and regulatory difficulties.

Even if we obtain regulatory approval for a product candidate, it would be subject to ongoing requirements by the FDA and comparable foreign regulatory authorities governing the manufacture, materials and facilities, qualification testing, quality control, further development, labeling, packaging, storage, distribution, post-approval clinical data, adverse event reporting, safety surveillance, import, export, advertising, promotion, recordkeeping and reporting of safety and other post-marketing information. These requirements include submissions of safety and other post-marketing information and reports, establishment registration and product listing, as well as continued compliance by us and/or our contract manufacturing organizations, or CMOs, and CROs for any post-approval clinical trials that we conduct. The safety profile of any product will continue to be closely monitored by the FDA and comparable foreign regulatory authorities after approval. If the FDA or comparable foreign regulatory authorities become aware of new safety information after approval of any of our product candidates, they may require labeling changes or establishment of a REMS, impose significant restrictions on a product’s indicated uses or marketing or impose ongoing requirements for potentially costly post-approval studies or post-market surveillance.