Sana Biotechnology (SANA) Risk Analysis

We use human stem cells in our research and development, including induced PSCs (iPSCs) and embryonic stem cells (ESCs), and one or more of our ex vivo cell engineering product candidates may be derived from human stem cells. The use of such cells in our research, or as starting cell lines in the manufacture of one or more of our product candidates, exposes us to numerous risks. These risks include difficulties in securing viable, appropriate, and sufficient stem cells as starting material, recruiting patients for our clinical trials, as well as managing a multitude of global legal and regulatory restrictions on the sourcing and use of these cells. For example, to the extent regulatory requirements differ across jurisdictions, we may face increased difficulty finding cells that meet all applicable jurisdictional requirements, or may be required to develop our product candidates using multiple different types of cells, which could increase the complexity and cost of development. In addition, certain cells may be subject to restrictions regarding the patient populations in which the resulting products can be used, which could limit the applicability and value of our product candidates. Further, in some states, use of embryonic tissue as a source of stem cells is prohibited and many research institutions have adopted policies regarding the ethical use of human embryonic tissue. If these regulations, policies, or restrictions have the effect of limiting the scope of research or other activities we can conduct using stem cells, our ability to develop our ex vivo cell engineering product candidates may be significantly impaired, which could have a material adverse effect on our business. Additionally, the use of stem cells generally, and ESCs, in particular, has social, legal, and ethical implications. Certain political and religious groups continue to voice opposition to the use of human stem cells in drug research, development, and manufacturing. Adverse publicity due to ethical and social controversies surrounding the use of stem cells could lead to negative public opinion, difficulties enrolling patients in our clinical trials, increased regulation, and stricter policies regarding the use of such cells, which could harm our business and may limit market acceptance of any of our product candidates that may receive regulatory approval. In addition, clinical experience with stem cells, including iPSCs and ESCs, is limited. We are aware of only a limited number of products utilizing iPSCs or ESCs as a starting material that have received marketing approval from the FDA or a comparable foreign regulatory authority. Therefore, patients in our clinical trials may experience unexpected side effects, and we may experience unexpected regulatory delays prior to or, if approval were to be granted, after regulatory approval. Furthermore, manufacturing and development of our stem cell-derived product candidates will require that we obtain suitable donor material from eligible and qualified human donors. If we are unable to obtain sufficient quantities of suitable donor material, or if we are unable to obtain such material in a timely manner, we may experience delays in manufacturing such product candidates, which would harm our ability to conduct clinical trials for or to commercialize these product candidates. Moreover, if the consent, authorization, or process for the donation and use of those materials is not obtained or conducted in accordance with applicable legal, ethical, and regulatory requirements, we could face delays in the clinical testing and approval of these product candidates, or, potentially, we could face claims by such human donors or regulatory authorities, which could expose us to damages and reputational harm.

A key element of our strategy is to identify and develop a pipeline of product candidates using our ex vivo and in vivo cell engineering platforms and advance those product candidates through clinical development for the treatment of various different diseases. The scientific research that forms the basis of our efforts to develop product candidates with our platforms is still ongoing. We are not aware of any FDA-approved therapeutics that are cell products derived from pluripotent stem cells (PSCs) or that utilize our fusogen technology. Further, the scientific evidence that supports the feasibility of developing therapeutic treatments based on our platforms is preliminary, limited, and remains ongoing. We are therefore exposed to a number of unforeseen risks, and it is difficult to predict the types of challenges and risks that we may encounter during development of our product candidates. Preclinical and clinical testing of product candidates is inherently unpredictable and may lead to unexpected results, in particular when such product candidates are based on novel technologies. For example, we have not tested our cell engineering platforms on all cell types or in all microenvironments, and results from one cell type or microenvironment may not translate into other cell types or microenvironments. In addition, our current gene editing approaches rely on novel gene editing reagents that may have unanticipated or undesirable effects or prove to be less effective than we expect. Also, we are in the early stages of testing product candidates developed using our cell engineering platforms in humans, and most of our current data are limited to animal models and preclinical cell lines and assays, which may not accurately predict the safety and efficacy of our product candidates in humans. Additionally, we and third parties may have limited preclinical and clinical data, and a more limited understanding generally, with respect to certain indications, such as autoimmune diseases, and we cannot predict the extent to which the safety and efficacy of a product candidate may vary across indications. We may encounter significant challenges creating appropriate models and assays for evaluating the safety, purity, and efficacy of our product candidates and may not be able to provide sufficient data or other evidence, to the satisfaction of regulatory authorities, that certain unexpected results observed in preclinical and clinical testing of our product candidates are not indicative of the potential safety issues of such product candidates. In addition, we may use manufacturing reagents and materials across various programs and initiatives. Certain reagents and materials may be novel and have unknown or unanticipated effects, including with respect to a product candidate's safety, efficacy, or manufacturability. Any unanticipated or adverse effects related or attributed to such reagents or materials could affect all the programs and initiatives in which they are used, and result in delays and harm our ability to timely and successfully progress our product candidates through preclinical and clinical development. We may develop program plans and timelines for certain product candidates based on our experience with such product candidates in different indications or with other product candidates that incorporate or were developed with the same technologies based on our expectation that such product candidates will perform and act similarly. However, our product candidates may reveal unexpected, important differences, including with respect to safety or efficacy, when developed in different indications or as compared to such other product candidates, including differences that may require changes to the manufacturing process or clinical development plan that require additional time and resources beyond what we initially anticipated. Any such occurrence could require us to adjust or alter our development plans, which could delay, harm, or prevent our ability to develop and commercialize such product candidates. In addition, product candidates developed with our hypoimmune and fusogen technologies have potential safety risks, including those related to genotoxicity associated with the delivery of genome-modifying payloads. For example, DNA sequences that randomly integrate into a cell's DNA may increase the risk for or cause certain cancers. Additionally, gene editing approaches may edit the genome at sites other than the intended DNA target or cause DNA rearrangements, each of which may have oncogenic or other adverse effects. PSC-derived cell products may have potential safety risks related to genomic and epigenomic variations that have occurred or may occur during the manufacturing process. We cannot always predict the types and potential impact of these genomic changes, including whether certain changes are or may eventually be harmful. Accordingly, it may be difficult for us to conduct the level of testing and assay development necessary to ensure that our PSC-derived cell product candidates have an acceptable safety profile when used in humans. These risks related to genetic variation are also relevant to any product candidates we may develop using donor-derived cells. Additionally, our stem cell-based product candidates have potential safety risks that may result from cells that are undifferentiated or have not been completely differentiated to the desired phenotype and lead to oncogenic transformations or other adverse effects. As a result, it is possible that safety events or concerns could negatively affect the development of our product candidates, as described elsewhere in these Risk Factors. Given the novelty of our technologies, we intend to work closely with the FDA and comparable foreign regulatory authorities to perform the requisite scientific analyses and evaluation of our methods to obtain regulatory approval for our product candidates. However, due to a lack of experience with similar therapeutics or delivery methods, the regulatory pathway with the FDA and comparable foreign regulatory authorities may be more complex, time-consuming, and unpredictable relative to more well-known therapeutics. For example, even if we obtain human data to support continued evaluation and approval of our product candidates, the FDA or comparable foreign regulatory authorities may lack experience in evaluating the safety and efficacy of therapeutics similar to our product candidates or may scrutinize such data more closely than data generated from more established types of biological products. In addition, given that there are no approved PSC-derived cell therapy products on the market in the United States, and only a limited number of such products on the market outside of the United States, the FDA and comparable foreign regulatory authorities may not have established consistent standards by which to evaluate the safety of such products, and any such standards that they do establish may subsequently change. Moreover, the FDA remains focused on potential safety issues associated with gene and cell therapy products, and as the number of new gene and cell therapy product candidates submitted for FDA review has increased in recent years, the number of clinical holds imposed by the FDA has also increased. For example, the FDA has placed clinical holds on certain product candidates pending further evaluation of genomic abnormalities detected in as few as a single patient following administration of such product candidates. We cannot be certain that the FDA or comparable foreign regulatory authorities will determine that the potential safety risks associated with our product candidates outweigh the potential therapeutic benefits in each indication for which we develop our products, and that they will allow us to commence clinical trials of such product candidates in a timely manner, or at all, or to continue such clinical trials in accordance with our timelines or at all after they have commenced. If we become subject to a clinical hold with respect to any of our product candidates due to a potential safety issue, we cannot guarantee that we will be able to provide the applicable regulatory authority with sufficient data or other evidence regarding the safety profile of such product candidate such that we will be able to commence or resume clinical development of such product candidates in a timely manner or at all. Any such event could delay clinical development of such product candidate, including in other indications, or our other product candidates, increase our expected development costs, increase the length of the regulatory review process, and delay or prevent commercialization of our product candidates. In addition, the evaluation process for our product candidates will take time and resources and may require independent third-party analyses, and our product candidates may ultimately not be accepted or approved by the FDA or comparable foreign regulatory authorities. As such, even if we are successful in building a pipeline of product candidates from our ex vivo and in vivo cell engineering platforms, we cannot be certain that such efforts will lead to the development of approvable or marketable products, either alone or in combination with other therapies. In response to reports of T cell malignancies in patients that previously received chimeric antigen receptor (CAR) T cell immunotherapies, the FDA announced in November 2023 its investigation into the risk of secondary cancers and the need for regulatory action for such therapies as a class and advised of new patient monitoring and reporting requirements with respect to such therapies. In January 2024, the FDA imposed a class-wide boxed warning requirement regarding the occurrence of T cell malignancies for all approved CAR T therapies. The FDA has noted that it currently believes that the overall benefits of these therapies continue to outweigh their potential risks for their approved uses. However, all currently approved CAR T cell immunotherapies are approved only in oncology indications, and there can be no assurance that the FDA or comparable foreign regulatory authorities will reach the same risk-benefit determination in other indications, such as autoimmune diseases. To the extent the FDA views in vivo CAR T cell therapies as posing similar or additional risks to those posed by the ex vivo CAR T therapies that were the subject of these FDA actions, the FDA may require us to take certain actions in connection with any in vivo CAR T cell clinical trials we may conduct or we may otherwise receive correspondence from the FDA regarding these developments. It is unclear at this time how changes in the leadership of the FDA and other government administration actions and changes will impact our operations and future interactions with the FDA. Additionally, we and our product candidates may be subject to further regulatory actions or requirements of the FDA or comparable foreign regulatory authorities relating to these therapies, such as requiring a black box warning or other labeling disclosures for any approved products. The occurrence of any of the foregoing could increase the cost and complexity of development and commercialization of, and limit the commercial opportunity for, such product candidates, any of which could have a material adverse effect on our business.

Our ability to generate revenue from sales of any of our product candidates, which we do not expect to occur for at least the next several years, if ever, will depend heavily on the timely and successful identification, development, regulatory approval, and eventual commercialization of any such product candidates, which may never occur. To date, we have not generated revenue from sales of any products, and we may never be able to develop, obtain regulatory approval for, or commercialize a marketable product. Before we generate any revenue from product sales of any of our current or potential future product candidates, we will need to manage research, preclinical, clinical, and manufacturing activities, including undertaking significant clinical development, obtain regulatory approval in multiple jurisdictions, establish manufacturing supply, including commercial manufacturing supply, and build a commercial organization, which will require substantial investment and significant marketing efforts. We may never receive regulatory approval for any of our product candidates, which would prevent us from marketing, promoting, or selling any of our product candidates and generating revenue. The successful development of our product candidates will depend on or be affected by numerous factors, including the following: - our successful and timely completion of preclinical studies and clinical trials for which the FDA and any comparable foreign regulatory authorities agree with the design, endpoints, and implementation;- the sufficiency of our financial and other resources to complete the necessary preclinical studies and clinical trials and manufacturing activities necessary to support such studies and trials;- the timely receipt of regulatory approvals or authorizations to conduct clinical trials;- our ability to timely and successfully initiate, enroll patients in, and complete clinical trials;- our ability to demonstrate to the satisfaction of the FDA or any comparable foreign regulatory authority that the applicable product candidate meets the FDA's or such comparable foreign regulatory authority's legal standards with respect to safety, purity, and potency, or efficacy, which may include, among other things, demonstrating that the benefits of the product candidate outweigh its known risks for the intended patient population, and that such product candidate can be manufactured in accordance with applicable legal requirements;- the timely receipt of marketing approvals for our product candidates from applicable regulatory authorities, including the impact of any changes to the FDA's Accelerated Approval Program;- our ability to address any potential interruptions or delays resulting from external factors, including those related to the current global geo-political, business, and economic environment, including any changes in government administration policy positions;- the extent of any clinical or regulatory setbacks experienced by other companies developing similar products or within adjacent fields, including cell-based therapies and the fields of gene editing and gene therapy, or publications or press coverage related to such therapies and fields, which could negatively impact the perceptions of the value and risk of our product candidates and technologies;- the extent of any post-marketing approval commitments we may be required to make to applicable regulatory authorities, including the conduct of any post-marketing approval clinical studies, and our ability to comply with any such commitments; and - our ability to establish, scale up, and scale out, either alone or with CDMOs, manufacturing capabilities for clinical supply of our product candidates for our clinical trials and, if any of our product candidates are approved, commercial supply (including licensure) of such product candidates. If we experience issues or delays with respect to any one or more of these factors, we could experience significant delays or be unable to successfully develop and commercialize our product candidates, which would materially adversely affect our business, financial condition, and results of operations.

A key component of our strategy is to acquire and in-license technologies to support our mission of using engineered cells as medicines. Our ex vivo and in vivo cell engineering technologies represent an aggregation of years of innovation and technology from multiple academic institutions and companies, including hypoimmune technology that we licensed from the President and Fellows of Harvard College (Harvard) and The Regents of the University of California (UCSF), our fusogen technology that we acquired from Cobalt Biomedicine, Inc. (Cobalt), and gene editing technology that we licensed from Beam Therapeutics Inc., among others. We continue to actively evaluate various acquisition and licensing opportunities on an ongoing basis. The level of success of these acquisition and in-licensing arrangements, including any that we may enter into in the future, will depend on the risks and uncertainties involved, including: - unanticipated liabilities related to acquired companies;- difficulty integrating acquired personnel, technologies, and operations into our existing business;- difficulty retaining key employees, including of any acquired businesses;- diversion of management time and focus from operating our business to management of acquisition and integration efforts;- increases in our expenses and reductions in our cash available for operations and other uses;- higher than expected acquisition or integration costs;- disruption in our relationships with collaborators, key suppliers, manufacturers, or customers as a result of an acquisition;- incurrence of substantial debt or dilutive issuances of equity securities to pay transaction consideration or costs;- possible write-offs of assets, goodwill or impairment charges, or increased amortization expenses relating to acquired businesses;- difficulty in and cost of combining the operations and personnel of any acquired business with our own; and - challenges integrating acquired businesses into our business, including our existing operations and culture. For example, we have conducted several portfolio prioritizations to consolidate our resource allocation to fewer programs, resulting in, among other things, workforce reductions. Most recently, we conducted a portfolio prioritization to prioritize future development of SC451, our type 1 diabetes program, and programs enabled by our fusogen platform, and suspended development of and further internal investment in our two allogeneic cell therapy CAR T programs. Furthermore, we regularly evaluate our portfolio and may conduct further portfolio prioritizations in the future, which could result in the suspension, discontinuation, or divestiture of certain programs that are our current focus of development, which increases the risk that the benefits we expected from any acquired technologies, such as the fusogen platform, may be more expensive and difficult to obtain or may not occur at all. In addition, foreign acquisitions and licensing arrangements are subject to additional risks, including those related to integration of operations across different cultures and languages, currency risks, potentially adverse tax consequences of overseas operations, and the particular economic, political, regulatory, and compliance risks associated with specific countries. The occurrence of any of these risks or uncertainties may preclude us from realizing the anticipated benefit of any acquisition or licensing arrangement, and our financial condition may be harmed. Additionally, we may not be successful in our efforts to acquire, obtain rights to, or otherwise access certain technologies or products that are necessary for the success of our product candidates or technologies on acceptable terms or at all, including because we may be unable to successfully or timely negotiate the terms of an agreement with the third-party owner of such technology or products or such third party may have determined to deprioritize such technology or products. Such transactions, as well as other strategic relationships we may enter into, may also be impacted by policies of or actions by certain regulatory authorities, such as the Federal Trade Commission (FTC), that have jurisdiction over various aspects of such transactions and relationships. If we are not able to acquire, obtain rights to, or otherwise access certain technologies or products on which certain of our product candidates or technologies may depend, it may be necessary for us to delay, reduce, or curtail the development of such product candidates or technologies, or incur additional costs in order to continue development without such rights.

Before an IND or comparable foreign submission can be submitted to the FDA or a comparable foreign regulatory authority and be cleared or otherwise become effective, which is a prerequisite for conducting clinical trials on human subjects, a product candidate must successfully progress through extensive preclinical studies, which includes preclinical laboratory testing, animal studies, and formulation studies conducted in accordance with good laboratory practices. In addition, to obtain the requisite regulatory approvals to ultimately market and sell any of our product candidates, we or any future collaborator for such product candidate must satisfy the FDA's or a comparable foreign regulatory authority's legal standards with respect to safety, purity, and potency, or efficacy, which may include, among other things, demonstrating through adequate and well-controlled clinical trials that the benefits of the product candidate outweigh its known risks for the intended patient population. Preclinical and clinical testing is inherently unpredictable. We may obtain positive data from early research or preclinical studies involving our product candidates and technologies, but subsequently encounter unexpected or unexplained results in later preclinical or clinical studies, including due to factors unrelated to our product candidates and technologies, that may cause the relevant product candidates or technologies to be unsuitable for further development. We may also need to perform additional research and preclinical or clinical studies for various reasons, including to determine the cause of any unexpected results, including whether such results were caused by our product candidates or technologies or other factors. Any of the foregoing could delay our development timelines or prevent us from continuing further development at all. Even if we obtain positive results from preclinical or clinical studies of our product candidates or technologies, success in preclinical or clinical studies does not ensure that later preclinical studies or clinical trials will be successful. A number of biotechnology and pharmaceutical companies have suffered significant setbacks in clinical trials, even after positive results in earlier preclinical or clinical studies, such as adverse findings observed while clinical trials were underway or safety or efficacy observations during clinical trials, including previously unreported adverse events, and we cannot be certain that we will not face similar setbacks. The design of a clinical trial can determine whether its results have the potential to support approval of a product, and flaws in a clinical trial's design may not become apparent until the clinical trial is well advanced. In addition, the results of our preclinical animal studies, including our non-human primate (NHP) studies, may not be predictive of the results of subsequent clinical trials involving human subjects. Product candidates may fail to show the desired pharmacological properties or safety and efficacy traits in clinical trials despite having successfully progressed through preclinical studies or earlier clinical trials. If we fail to obtain positive results in preclinical studies or clinical trials involving any of our product candidates or technologies, the development timeline and regulatory approval and commercialization prospects for any relevant product candidate, and, correspondingly, our business and financial prospects, would be negatively impacted.

Applicable laws and regulations require us to conduct preclinical testing of our product candidates in animals before initiating clinical trials involving humans, and the results and timing of such testing are uncertain. We may experience delays in or difficulty completing studies of our product candidates in animals for various reasons. For example, due to global supply chain issues caused by global geo-political, economic, and other factors beyond our control, as described elsewhere in these Risk Factors, we have experienced and may continue to experience difficulty and increased costs in accessing animal models, specifically certain NHP models, which could delay completion of our preclinical studies involving such models or harm our ability to conduct or complete such studies at all, and could limit the potential patient population for our product candidates. In addition, animal testing has been the subject of controversy and adverse publicity. Animal rights groups and others have attempted to stop animal testing by pressing for legislation and regulation and by disrupting such testing through protests and other means. To the extent these attempts are successful, our research and development activities may be interrupted or delayed, become more expensive, or both. We are required to submit an IND or comparable foreign submission to the FDA or comparable foreign regulatory authorities with respect to each product candidate prior to commencing a clinical trial for such product candidate in the applicable jurisdiction. Although we plan to submit INDs for each of our current and future product candidates, we may not be able to submit future INDs in accordance with our expected timelines for various reasons, including due to: - manufacturing challenges or delays, including due to challenges associated with scaling up our manufacturing processes and developing and validating assays or otherwise meeting applicable regulatory requirements;- delays in our IND-enabling preclinical studies; or - feedback from the FDA or comparable foreign regulatory authorities that requires us to conduct additional testing or change the design of a planned clinical trial prior to submitting such IND or comparable foreign submission. Moreover, we cannot guarantee that submission of an IND or comparable foreign submission for a product candidate will result in the FDA or comparable foreign regulatory authorities allowing clinical trials of that product candidate to commence in accordance with our timelines or expectations or at all, including, for example, due to delays in review or approval timelines caused by disruptions and other factors impacting the FDA or comparable foreign regulatory authorities, or that, once begun, issues will not arise that require suspension or termination of such clinical trials. For example, the FDA or a comparable foreign regulatory authority may accept an IND or comparable foreign submission for a product candidate but place clinical trials of such product candidate on hold pending the results of additional testing or the development of additional assays, or may otherwise refuse or terminate the applicable submission. Further, because legal and regulatory requirements for conducting clinical trials vary across jurisdictions, our receipt of authorization to conduct clinical trials in one jurisdiction does not guarantee such authorization will be granted in other jurisdictions. In addition, such legal and regulatory requirements may change over time, including in a manner that could cause us to incur delays or additional expense in order to comply. For example, the regulatory landscape related to clinical trials in the European Union (EU) continues to evolve. The EU Clinical Trials Regulation (CTR), which was adopted in April 2014 and repealed the EU Clinical Trials Directive, became applicable on January 31, 2022. Unlike the EU Clinical Trials Directive, which required a separate clinical trial application (CTA) to be submitted to both the competent national health authority and an independent ethics committee in each EU member state in which the clinical trial will be conducted, the CTR provides for a centralized process via the Clinical Trials Information System (CTIS). The CTR allows sponsors for multi-center trials to make a single submission and obtain authorizations in multiple jurisdictions. The system routes information to all concerned member states at once, and member states then coordinate their review of the dossier in a joint assessment, with a separate assessment by each member state with respect to specific requirements related to its own territory, including ethics rules. Typically, one country is appointed rapporteur (lead assessor) with others as co-rapporteurs, producing a single assessment report for all and a harmonized decision. Once the CTA is approved, clinical studies may proceed. Following a three-year transition period, effective January 31, 2025, any trials approved under the Clinical Trials Directive that continue running must comply with the CTR, and their sponsors must enter information regarding the trials in the CTIS. Compliance with the CTR requirements by us and our service providers, such as CROs, may impact our development plans. For example, because the CTR requires coordination of application review and processing across multiple member states, our ability to commence clinical trials in accordance with our timelines could be delayed. Further, the United Kingdom (UK) withdrew from the EU in 2020, and uncertainty remains as to whether and to what extent certain UK laws and regulations will be aligned with those of the EU, including the CTR, which does not apply in the UK. Local requirements in the UK and the EU have diverged and may further diverge in the future, which could impact any UK clinical and development activities we may conduct. For example, significant updates to the UK clinical trials regulations came into force in April 2026. In addition, clinical trial submissions in the UK must be separate from those submitted to EU member states, adding further complexity, cost, and potential risk to any clinical and development activity in the UK. If we are unable to satisfy applicable legal or regulatory requirements or standards for an IND or comparable foreign submission, or experience delays in doing so, clinical development of our product candidates may be delayed or we may be unable to execute clinical trials of the applicable product candidate in the relevant jurisdiction. For example, we may decide not to submit an IND or comparable foreign submission in certain jurisdictions due to applicable legal or regulatory requirements in such jurisdiction, including based on future changes to such requirements. Additionally, even if regulatory authorities agree with the design and implementation of the clinical trials set forth in an IND or a comparable foreign submission, we cannot guarantee that such regulatory authorities will not change their requirements in the future, which could require us to make costly changes to and delay the conduct of our clinical trials or require suspension or termination of such trials entirely. In addition, because the manufacturing of our product candidates is in its early stages and continues to evolve, we expect that manufacturing-related matters such as chemistry, manufacturing, and controls, including product specifications, will continue to be a focus of regulatory review of our INDs or comparable foreign submissions, which may delay or prevent our ability to proceed with the relevant clinical trials. These considerations also apply to new clinical trials we may submit as amendments to existing INDs or comparable foreign submissions.

Clinical trials are expensive, complex, and can take many years to complete, and their outcomes are inherently uncertain and their data subject to varying interpretations and analyses. Product candidates in later-stage clinical trials may fail to produce the same results as observed in earlier trials or fail to show the desired safety and efficacy characteristics despite having progressed through preclinical studies and earlier clinical trials. We do not know whether any clinical trials we may conduct will begin on time, need to be redesigned, enroll patients on time, or be completed on schedule, if at all. Clinical trials may be delayed, suspended, or terminated, or may not be able to be conducted at all, for a variety of reasons, including the following: - delays in or failure to obtain regulatory authorization to commence a trial;- delays in or failure to obtain institutional review board (IRB) or ethics committee (EC) approval for each clinical trial site;- delays in or failure to reach agreement with prospective CROs and other service providers, clinical trial sites, or companion diagnostic development partners on acceptable terms, or at all;- difficulty in recruiting clinical trial investigators or clinical trial sites of appropriate competencies and experience, including due to pre-existing commitments or resource and other infrastructure constraints, including resource allocation to other clinical trials, such as those of our competitors;- delays in or inability to timely manufacture sufficient quantities of a product candidate for use in clinical trials;- failure of a product candidate to meet acceptable quality or stability standards, or failure to manufacture product candidates in accordance with cGMP and other applicable laws, regulations, and guidelines;- challenges related to the delivery, handling, and administration of product candidates at clinical trial sites;- delays in establishing the appropriate dosage levels in clinical trials;- delays in or inability to recruit, enroll, and retain suitable patients in a trial, as discussed elsewhere in these Risk Factors;- failure of patients to complete a trial or return for post-treatment follow-up;- difficulty in identifying the sub-populations that are the target group for a particular trial, which may delay enrollment and reduce the power of a clinical trial to detect statistically significant results;- clinical sites deviating from trial protocol or dropping out of a trial;- delays caused by the addition of new investigators or clinical trial sites or replacement of existing investigators or sites;- safety, efficacy, or other concerns arising out of clinical trials involving our product candidates or technologies, including clinical trials we conduct ourselves or those sponsored or initiated by investigators (ISTs);- events arising during the course of a clinical trial, such as safety or tolerability concerns relating to the relevant product candidate, that could cause us or governmental authorities, as applicable, to suspend or terminate a clinical trial or program or impose a clinical hold, including if participants are being exposed to unacceptable health or safety risks or experiencing undesirable side effects or other adverse events, there are other unfavorable characteristics of the product candidate, or regulators deem our product candidate to have the potential for comparable undesirable side effects or risks to those of other product candidates, including those under development by us or third parties, due to compositional, biologic, mechanistic, sourcing, or other similarities;- the failure of third-party contractors to comply with regulatory requirements or meet their contractual obligations in a timely manner or at all;- changes in regulatory requirements, policies, and guidelines;- changes in the treatment landscape for our target indications that may make it more difficult to initiate or recruit patients for our clinical trials in certain jurisdictions or may make our product candidates no longer relevant;- claims that the product candidate being tested infringes third-party intellectual property rights, including any resulting injunctions that may prevent further use of such product candidates and interfere with the progress of the trial; and - business interruptions resulting from geo-political actions, including war and terrorism, natural disasters including earthquakes, typhoons, floods, and fires, or disease. Clinical trials must be conducted in accordance with the FDA's and comparable foreign regulatory authorities' legal requirements, regulations, and guidelines and are subject to oversight by these governmental authorities and IRBs or ECs of the medical institutions where the clinical trials are conducted. We could encounter delays if a clinical trial is suspended or terminated by us, by the IRBs or ECs of the institutions at which such trial is being conducted, by the Data Review Committee or 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, including following an inspection of clinical trial operations or a clinical trial site, for various reasons, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from use of the product candidate being tested, or changes in governmental regulations or administrative actions. In addition, the complexity and novelty of certain product candidates, the clinical trial design, and the indications for which such product candidates are being developed, as well as the combination of these factors, could negatively affect our ability to successfully execute and complete clinical trials of such product candidates in accordance with our timelines. For example, clinical trials of our product candidates may require specialized procedures, processes, or testing, which could be complex to implement and introduce variability across clinical trial sites. In addition, clinical trials involving certain indications, such as autoimmune diseases, may require the involvement and alignment of medical professionals across various specialties. Additionally, we may evaluate certain of our product candidates in multiple indications and across a broad range of diseases in a single clinical trial. Because these diseases can vary significantly, doing so may introduce additional complexities and challenges with executing our clinical trials, any of which could increase the time and expense required to commence and complete the applicable trial. Further, to the extent we develop our product candidates for multiple indications, the occurrence of any potential safety issues or significant side effects with respect to a particular indication or study could negatively affect the development of such product candidate in all indications. In addition, we cannot guarantee that any positive safety or other results we observe in a certain indication will also be observed in any other indication. We and third parties involved in our clinical trials may not have sufficient resources to adequately address such complexities in accordance with our timelines or at all. If we experience delays in completing, or are required to terminate, any clinical trial of our product candidates, the commercial prospects of the relevant product candidates will be harmed, and our ability to generate product revenues from these product candidates, if at all, will be delayed. In addition, any delays in completing or inability to complete our clinical trials will increase our costs and delay or jeopardize our ability to obtain regulatory approval for the relevant product candidate, commence product sales, and generate revenues. Significant clinical trial delays could also allow our competitors to bring products to market before we do or shorten any periods during which we have the exclusive right to commercialize our product candidates, which may impair our ability to commercialize our product candidates and harm our business and results of operations. Furthermore, as described elsewhere in these Risk Factors, we have relied and will continue to rely on third parties that are responsible for executing or supporting our clinical trials, such as CROs and clinical trial sites, including principal investigators, and to the extent they fail to timely and properly perform their obligations, we may experience program delays, incur additional costs, or both, which may harm our business. In addition, we may experience delays and incur additional costs with respect to any clinical trials that we conduct in countries outside the United States, including as a result of increased shipment and distribution costs, compliance with additional or different regulatory requirements, and the engagement of non-United States-based CROs or other third parties, and may also be exposed to various other risks, including those associated with clinical investigators who are unknown to the FDA, transfers and use of data across jurisdictions, and different standards of diagnosis, screening, and medical care.

Successful and timely initiation and completion of clinical trials will require that we timely enroll and retain a sufficient number of patients. Any clinical trials we conduct may be subject to delays for a variety of reasons, including as a result of patient enrollment taking longer than anticipated, patient withdrawal, or the occurrence of adverse events. These types of developments could cause us to delay the trial or halt further development of the relevant product candidate. Patient enrollment and retention in clinical trials depend on many factors, including: - the size and nature of the patient population;- the severity of the disease under investigation, including patients' prior lines of therapy and treatment;- eligibility and exclusion criteria for the trial;- the number and location of clinical trial sites;- the proximity of patients to clinical sites;- the design of the clinical protocol;- the ability to obtain and maintain patient consents;- competition with other sponsors or clinical trials for clinical trial sites or patients;- the perceived risks and benefits of the product candidate under evaluation, including risks and benefits associated with other product candidates, including those under development by us or third parties, that may be perceived to be similar to our product candidates due to compositional, biologic, mechanistic, sourcing, or other similarities;- the ability to recruit and availability of clinical trial investigators and sites with the appropriate competencies, experience, and resources;- the risk that enrolled patients will drop out of the trial before administration of the product candidate or trial completion;- the availability of patients resulting from the impact of any pandemic, epidemic, or disease outbreak;- the availability of, and clinicians' and patients' satisfaction with, existing and new drugs approved for the indication the clinical trial is investigating; and - clinicians' and patients' perceptions as to the potential advantages of the product candidate being studied in relation to other available therapies, including any new therapies that may be approved for the indications the clinical trial is investigating or the approved label expansion of an existing therapy into the indication the clinical trial is investigating. In particular, our clinical trials will compete with other clinical trials that are in the same therapeutic areas as our product candidates. In addition, because the number of qualified clinical investigators and clinical trial sites is limited, we expect to conduct at least some of our clinical trials at the same sites as those used by our competitors. Competition with other clinical trials may reduce the number and types of patients available to participate in our trials, as some patients who might have opted to enroll in our trials may instead opt to enroll in a trial being conducted by one of our competitors. Moreover, enrolling patients in clinical trials for diseases for which there is an approved standard of care is challenging, as patients will first receive the applicable standard of care, and many patients who respond positively to the standard of care do not enroll in clinical trials. In addition, although patients who fail to respond positively to the standard of care treatment may be eligible for clinical trials of our product candidates, treatment with prior regimens may render our product candidates less effective in clinical trials. As a result, the number of eligible patients who have the potential to benefit from our product candidates could be limited, which could extend development timelines or increase costs for our programs. The circumstances described above and elsewhere in these Risk Factors may make it difficult for us to enroll enough patients to complete our clinical trials in a timely and cost-effective manner. If we are unable to timely recruit and enroll patients for our clinical trials, enroll a sufficient number of patients to complete our clinical trials as planned, or retain patients in our clinical trials, we may be required to change our trial design, recruit and enroll a different population of patients than we anticipated, or recruit and enroll patients in geographies that are more challenging. We may not be fully prepared to address such challenges, and even if we are able to address such challenges, the results of our clinical trials may be negatively impacted. Delays in the completion of any clinical trial we may conduct will increase our costs, slow down the development and approval process, and delay or potentially jeopardize our ability to commence product sales and generate revenue for the relevant product candidate. In addition, some of the factors that may 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.

To obtain the requisite regulatory approvals to market and sell any of our current or future product candidates, we or our potential future collaborators must demonstrate with substantial evidence from adequate and well-controlled clinical trials of the product candidate, and to the satisfaction of the FDA or comparable foreign regulatory authorities, that such product candidate meets the FDA's or such comparable foreign regulatory authorities' legal standards with respect to safety, purity, and potency, or efficacy, which may include, among other things, demonstrating through adequate and well-controlled clinical trials that the benefits of the product candidate outweigh its known risks for the intended patient population. 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 development process. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization. We may be unable to establish clinical endpoints that applicable regulatory authorities would consider clinically meaningful. Clinical trials of our product candidates or product candidates developed using our technologies (including those conducted by third parties, such as in the case of ISTs) may not demonstrate that such product candidates or technologies have efficacy and safety profiles necessary to support further development and regulatory approval. Safety or efficacy results for a particular clinical trial, or between different clinical trials of the same product candidate, can vary significantly due to numerous factors, including differences in the size and type of the patient populations, variety of patients and disease types within a trial, changes in, adherence to, and the level of consistency in the conduct of clinical trial protocols and trial procedures, and the rate of dropout among clinical trial participants. If the results of clinical trials are inconclusive with respect to the efficacy of our product candidates or those developed using our technologies, if we do not meet the clinical endpoints with statistical and clinically meaningful significance, or if there are safety concerns associated with our product candidates or technologies, we may experience delays in obtaining marketing approval, or we may not obtain approval at all. Additionally, any safety concerns observed in any clinical trial of one of our product candidates, or those developed using our technologies, in our targeted indications could limit the prospects for regulatory approval of such product candidate in those and other indications or the prospects of other product candidates we may develop that are perceived to have the potential for similar safety concerns. Additionally, some of our trials may be open-label trials in which the patient and/or investigator know whether the patient is receiving the investigational product candidate. Data generated from open-label clinical trials may exaggerate any therapeutic effect, as patients and/or investigators are aware when a patient has received the experimental treatment, which may cause investigators to interpret the information of the treated group more favorably. Therefore, positive results observed in open-label trials may not be replicated in later controlled trials. Even if we or our collaborators (or other third parties, in the case of ISTs) successfully complete any clinical trials, clinical data are often susceptible to varying interpretations and analyses. We cannot guarantee that the FDA or comparable foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. Even if positive results are observed in clinical trials, we cannot guarantee that the FDA or comparable foreign regulatory authorities will view our product candidates as having efficacy. Further, the FDA or comparable foreign regulatory authorities may not agree with our manufacturing strategy or may not find comparability between our clinical trial product candidates and proposed commercial product candidates, which may result in regulatory delays or a need to perform additional clinical studies. Moreover, clinical trial results that may be acceptable to support approval of a certain scope in one jurisdiction may be deemed inadequate to support regulatory approval, or may only be deemed sufficient to support a narrower scope of approval, in other jurisdictions. If the FDA or comparable foreign regulatory authorities determine that the results of clinical trials of our product candidates are not adequate to support approval of a marketing application, we may experience delays in obtaining, or fail to obtain, approval of our product candidates, or we may be required to expend significant additional resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates. Even if regulatory approval is obtained for a product candidate, the terms of such approval may limit the scope and use of the specific product candidate, which may also limit its commercial potential.

Our product candidates may cause serious adverse, undesirable, or unacceptable side effects, which could cause us or regulatory authorities to interrupt, delay, or halt our future clinical trials and could result in a more restrictive label or the delay or denial of regulatory approval by the FDA or comparable foreign authorities. We do not currently, and in the future may not, have sufficient clinical data or other information to enable us to fully anticipate the side effects of our product candidates. Accordingly, we may observe unexpected side effects or higher levels of expected side effects in clinical trials of our product candidates, including adverse events known to occur in the same classes of therapeutics, which may include infusion reaction, cytokine release syndrome, graft-versus-host disease, neurotoxicities, severe infection, and certain cancers. Results of our clinical trials could reveal a high and unacceptable severity and prevalence of these or other side effects associated with our product candidates. In such an event, clinical trials of such product candidates could be suspended or terminated, and the FDA or comparable foreign regulatory authorities could order us to cease further development of or deny approval of such product candidates for any or all targeted indications. In addition, the FDA or comparable foreign regulatory authorities may more closely scrutinize any side effects or safety concerns associated with our product candidates in the context of the potential benefits observed in diseases that are not immediately life-threatening, such as certain autoimmune diseases, which could harm our ability to develop or obtain regulatory approval for applicable product candidate in such diseases. Moreover, the occurrence of such side effects could negatively affect our ability to recruit and enroll patients in our clinical trials or the ability of enrolled patients to complete the clinical trials, or result in product liability claims. For example, patients with diseases that are not immediately life-threatening, including certain autoimmune diseases, and their physicians may be less likely to enroll or recommend enrollment in clinical trials of our product candidates if there is a risk of certain side effects or safety concerns and may be more likely to cease their participation in such clinical trials if they experience certain side effects. Similar events may occur if it is determined that there are side effects or safety concerns associated with other products or product candidates that are, or are perceived to be, similar to ours. Any of these occurrences could significantly harm our business, financial condition, and prospects. Further, clinical trials by their nature involve only a sample of the potential patient population. Because our clinical trials will involve only a limited number of patients and limited duration of exposure to our product candidates, rare and severe side effects of our product candidates may not be apparent during early clinical trials and may only be uncovered once a significantly larger number of patients have been exposed to the product candidate, including during later-stage clinical trials or following commercialization, or when longer-term data is available. As such, even if applicable regulatory authorities initially determine that our product candidates have an acceptable safety profile for their intended use in humans, they may later prove to cause serious side effects in patients that we were unable to observe or predict during their clinical development. In the event that any of our product candidates receives regulatory approval and we or others later determine that such product may cause undesirable or unacceptable side effects, a number of potentially significant negative consequences could result, including: - regulatory authorities may withdraw or limit approvals of such product and require us to take such product off the market;- regulatory authorities may require the addition of labeling statements, specific warnings, or a contraindication or field alerts to physicians and pharmacies, or issue other communications containing warnings or other safety information about the product;- regulatory authorities may require a medication guide outlining the risks of such side effects for distribution to patients or that we implement a risk evaluation and mitigation strategy (REMS) plan to ensure that the benefits of the product outweigh its risks;- we may be required to change the therapeutic dose or the way the product is administered, conduct additional clinical trials, or change the labeling of the product;- we may be subject to limitations on how we may promote or manufacture the product;- sales of the product may decrease significantly;- we may be subject to litigation or product liability claims; and - our reputation may suffer. Any of these events could prevent us or our potential future partners from achieving or maintaining market acceptance of the affected product or could substantially increase commercialization costs and expenses, which in turn could delay or prevent us from generating significant revenue from the sale of any products.

From time to time, we may publicly disclose interim, topline, or preliminary data from our preclinical studies or clinical trials, which are based on a preliminary analysis of then-available data, and the final results and related findings and conclusions are subject to change following a more comprehensive review of the study or trial data. 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 at the time of our initial disclosure of data. Further, modifications or improvements to our manufacturing processes for a product candidate may result in changes to its characteristics or behavior that could cause the product candidate to perform differently and affect the results of our preclinical studies or planned or ongoing clinical trials of such product candidate, and potentially require us to conduct additional preclinical studies or clinical trials. As a result, the topline 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, topline, and preliminary data also remain subject to audit and verification procedures, including source data verification, that may result in the final data being materially different from the preliminary data we previously disclosed. As a result, these data should be viewed with caution until the final data are available. Similarly, preliminary or interim data from clinical trials 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. Adverse differences between preliminary or interim data and final data could significantly harm our business prospects. Additionally, disclosure of preliminary or interim data by us or our competitors, with respect to clinical trials of their product candidates, could result in volatility in the price of our common stock. Further, others, including regulatory authorities, investors, or analysts, may not accept or agree with our assumptions, estimates, calculations, conclusions, or analyses, or may interpret or weigh the importance of data, including any decisions we may make based on that data, particularly limited or preliminary data, differently than we do, which could impact the value of the particular program, the approvability or commercialization of the particular product candidate, and our company in general. If the interim, topline, or preliminary data that we report differ from actual results, or if others, including regulatory authorities, investors, or analysts, disagree with the conclusions reached, our ability to obtain approval for and commercialize our product candidates, as well as our business, operating results, prospects, and financial condition, could be harmed.

ISTs involving our product candidates or technologies pose or are subject to similar risks to those set forth elsewhere in these Risk Factors relating to clinical trials that we conduct ourselves. Although ISTs may provide us with clinical data that can inform the development strategy for our product candidates, we may have limited or no ability to control the timing, design, and conduct of such ISTs or regulatory matters with respect to such ISTs, including the submission, clearance or approval, or maintenance of any IND or comparable foreign submission required to conduct such ISTs. In addition, we may not control the data collection and reporting, including timing thereof, with respect to any ISTs, and may not control the manufacturing of the product candidate or technology to be tested in any such ISTs. A delay in the timely completion of or reporting of data from any IST, including as a result of manufacturing complications or delays, which could occur for various reasons such as the need to obtain additional licenses, delays in recruiting, enrolling, or retaining patients, or other potential issues, including those described in these Risk Factors, could have a material adverse effect on our ability to further develop our product candidates or to advance our product candidates through subsequent clinical trials. Negative results from an IST could have a material adverse effect on our business and prospects and the perception of our product candidates and technologies. Additionally, there is a possibility that ISTs may be conducted under less rigorous clinical standards than those used in company-sponsored clinical trials. For these or other reasons, the FDA and comparable foreign regulatory authorities may more closely scrutinize the resulting data and may not view these data as providing adequate support for future clinical trials, whether sponsored by us or third parties. In addition, any potential IST could demonstrate marginal efficacy or reveal clinically relevant safety concerns that could delay the further clinical development or regulatory approval of our product candidates. Further, data from a potential IST may fail to demonstrate efficacy for various reasons, including those unrelated to our product candidates or technologies, which may negatively impact the perception of such product candidates and technologies, despite their potential for future success. To the extent that the results of any ISTs raise safety or other concerns regarding our product candidates or technologies, regulatory authorities may question the results of such ISTs or other clinical trials involving the relevant product candidate or technology. Safety concerns arising from any ISTs may cause the FDA or comparable foreign regulatory authorities to impose partial or full clinical holds on clinical trials of our product candidates, including product candidates that were developed using the same technology or manufactured using the same reagents and materials as those product candidates that are the subject of such ISTs, which could delay or prevent us from advancing our product candidates into further clinical development and require us to discontinue our development of such product candidates. The occurrence of any of the foregoing would severely harm our business and prospects.