TCRX 10-K & 10-Q changes, risk factors and insider trading

Investment in biotechnology product development is a highly speculative undertaking and entails substantial upfront capital expenditures and significant risk that any potential product candidate will fail to demonstrate adequate efficacy or an acceptable safety profile, gain regulatory approval and become commercially viable. We are still in the early stages of development of our product candidates and have initiated clinical trials for certain of our product candidates. We have no products licensed for commercial sale and have not generated any revenue from product sales to date, and we continue to incur significant research and development and other expenses related to our ongoing operations. We have financed our operations primarily through equity issuances, borrowings under secured loan agreements in September 2022 and December 2024 and upfront payments under our existing or previous collaborations.

Our success depends on our ability to use our proprietary platform (i) to discover the natural targets of clinically relevant TCRs through our TargetScan technology,TCRs, (ii) to discover highly active TCRs for known targets through our ReceptorScan technology,targets, (iii) to genetically engineer patient- or donor-derived T cells safely and reproducibly through our T-Integrate technology,reproducibly, (iv) to obtain regulatory approval for product candidates derived from our proprietary platform and related technologies, and (v) to then commercialize our product candidates that address one or more indications. All of our product candidates will require significant additional clinical and non-clinical development, review and approval by the FDA or other regulatory authorities in one or more jurisdictions, substantial investment, access to sufficient commercial manufacturing capacity and significant marketing efforts before they can be successfully commercialized. OurSome of our product candidates are currently being evaluated in humans and may never become commercialized. Moreover, all of our current product candidates are being developed using our proprietary platform and leveragingleverage the same or similar technology,technology and use the same or similar manufacturing process and development program.processes. As a result, an issue with one product candidate or failure of any one program to obtain regulatory approval could adversely impact our ability to successfully develop and commercialize all of our other product candidates.candidates, particularly ones within the same clinical program.

the willingness of physicians, operators of clinics and patients to utilize or adopt any of our product candidates or future product candidates to treat heme malignancies or solid tumorspatients;

As of December 31, 2024,2025, we had $290.1$152.4 million in cash,cash and cash equivalents and marketable securities.equivalents. We believe that our existing cash,cash and cash equivalents and marketable securities will enable us to fund our current operating plan into the firstsecond quarterhalf of 2027. Accordingly, our existing cash,cash and cash equivalents and marketable securities will not be sufficient for us to fund any of our product candidates through regulatory approval, and we will need to raise substantial additional capital to complete the development and commercialization of our product candidates through equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements or other sources. We may also need to raise additional funds sooner if we choose to pursue additional indications for our product candidates or otherwise expand more rapidly than we presently anticipate.

Our ability to raise capital is subject to the risk of adverse changes in the market value of our stock. Periods of macroeconomic weakness or recession and heightened market volatility caused by adverse geopolitical developments could increase these risks, potentially resulting in adverse impacts on our ability to raise further capital on favorable terms. The impact of geopolitical tension, such as a deterioration in the bilateral relationship between the U.S. and China or in the ongoing conflicts between Russia and Ukraine, and in the Middle East, including resulting sanctions, export controls or other restrictive actions that may be imposed by the U.S. and/or other countries against governmental or other entities in, for example, Russia,could also could lead to disruption, instability and volatility in global trade patterns, which may in turn impact our ability to source necessary reagents, raw materials and other inputs for our research and development operations. In addition, political developments impacting government spending and international trade, including changes in trade agreements, potential government shutdowns and trade disputes and tariffs, including tariffs that have been or may in the future be imposed by the United States or other countries and future legislation or actions taken by the United States or other countries that restrict trade, and protectionist or retaliatory measures taken by the United States or other countries, may negatively impact markets and cause weaker macroeconomic conditions. Any of the abovementioned factors could affect our business, prospects, financial condition, and operating results. The extent and duration of any political instability and resulting market disruptions are impossible to predict but could be substantial. Any such disruptions may also have the effect of heightening many of the other risks and uncertainties described elsewhere in this “Risk Factors” section.

The U.S. Congress,Congress and the Trump administration,administration orhave anymade new administrationand may make substantial changes to fiscal, tax, and other federal policies that may adversely affect our business.

In 2017,Since the U.S.start Congress andof the Trump administration madein substantial2025, changesthere tohave U.S. policies, which included comprehensive corporate and individual tax reform. In addition, the Trump administration called forbeen significant changes to U.S. trade, healthcare, tax, immigration and government regulatory policypolicy. For example, the U.S. government has imposed substantial tariffs on most countries throughout the world and, despite the February 2026 U.S. Supreme Court ruling invalidating many of the tariffs imposed in President2025, Trump’shas secondfurther term.threatened Theto transitionscontinue betweento broadly impose tariffs, which could lead to corresponding punitive actions by the Trumpcountries andwith Biden presidential terms led to substantial changes inwhich the directionU.S. and focus of administrative and regulatory policies.trades. Changes to U.S. policy implemented by the U.S. Congress, the Trump administration or any future administration have impacted and may in the future impact, among other things, the U.S. and global economy, international trade relations, unemployment, immigration, healthcare, taxation, the U.S. regulatory environment, inflation and other areas. Although we cannot predict the impact, if any, of these changes to our business, they could adversely affect our business. Until we know what policy changes are made, whether those policy changes are challenged and subsequently upheld by the court system and how those changes impact our business and the business of our competitors over the long term, we will not know if, overall, we will benefit from them or be negatively affected by them.

Our future success depends on the successful development of our product candidates, which target heme malignancies and solid tumors utilizing TCR-T therapy product candidates. Advancing our product candidates creates significant challenges for us, including:

educating medical personnel about the administration of TCR-T therapy product candidates on a stand-alone basis or in combination with built-in immune and tumor modulators;

manufacturing TCR-T therapy product candidates efficiently and consistently without the use of viral vectors using our T-Integrate technology;

The process by which patient cells are converted into a TCR-T therapy product candidate has many steps that can influence quality and activity.

For example, we are planning a registrational trial for TSC-101, and based on feedback from regulatory authorities, we may need to modify our clinical trial design or may be delayed in initiating such trial. If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not positive or are only moderately positive or if there are safety concerns, our business and results of operations may be adversely affected and we may incur significant additional costs. Accordingly, our clinical trial costs are likely to be significantly higher than those for more conventional therapeutic technologies or drug product candidates.

We have established facilities and engaged third-party contract manufacturers to manufacture our current product candidates. We rely on outside vendors to manufacture supplies for our manufacturing process, and we expect to rely on outside vendors to help us manufacture our product candidates for registration-enabling additional clinical trials as well as commercial sales. We have not yet manufactured or processed any product candidates on a commercial scale and may not be able to do so. We plan to optimize the existing manufacturing process to support product commercialization. The process modifications we intend to introduce will require regulatory approval of our product candidates, which could delay the commercialization of the products. We cannot be sure that such changes in the process will result in therapies that are efficacious and viable for commercial sale. In addition, changes in the manufacturing process may result in the need to conduct additional bridging clinical trials to demonstrate product comparability.

We, and any third-party contract manufacturers we engage to support our clinical trials, may experience manufacturing difficulties due to limited manufacturing experience, resource constraints or as a result of labor disputes, geopolitical and economic tensions with China, including as a result of the escalation of tariffs or other trade restrictions under the newTrump administration or if previously proposed federal legislation known as the BIOSECURE ACT or a similar law were to be enacted,administration, or unstable political environments. The pharmaceutical industry in general, and our suppliers or other third parties on which we rely, may depend on China-based suppliers for certain raw materials, products and services, or other activities. If we or our suppliers are unable to depend on these China-based suppliers or service providers, we may not be able to engage a backup or alternative supplier in a timely manner or at all. This, in turn, could materially and adversely affect our or our suppliers’ ability to manufacture or supply products and product candidates which could materially and adversely affect our business. If we or any third-party contract manufacturers we engage were to encounter any of these difficulties, our ability to manufacture sufficient product supply for our preclinical studies and clinical trials, or to provide products for patients once approved, would be jeopardized.

Many of the materials and regents we expect to use in our processes are single or sole source, and/or have limited stability and as such supply disruptions could materially impact our ability to develop or manufacture products. In addition, thecertain cell processing equipmentequipment, consumables and tubing that we useused in our current manufacturing process is currentlyare sourced from a single supplier.supplier, or are otherwise available from a limited number of suppliers. Any interruption in the supply by those single source suppliers could impact our ability to continue development of any and all of our product candidates on the anticipated timelines or at all. We may be unable to obtain these materials and products for an indeterminate period of time if any of these third parties were to cease or interrupt production or otherwise fail to supply these materials or products to us for any reason, including due to regulatory requirements or actions (including recalls), adverse financial developments at or affecting the supplier, or labor shortages or disputes. Regional or single-source dependencies may in some cases accentuate these risks.

We cannot guarantee that our solid tumor product candidates will show any functionality in the solid tumor microenvironment. The cellular environment in which solid tumor cells thrive is generally hostile to T cells due to factors such as the presence of immunosuppressive cells, humoral factors and limited access to nutrients. Our TCR-T-based product candidates may not be able to access the solid tumor, and even if they do, they may not be able to exert anti-tumor effects in a hostile solid tumor microenvironment. As a result, ourwe have recently decided to focus on developing an in vivo engineering platform for TCR-T product candidates mayfor solid tumors, and our efforts are at a very early stage. Therefore, we do not yet know whether this platform will yield viable product candidates with the potential to demonstrate potency in solid tumors. If we are unable to make our product candidates function in solid tumors, our development plans and business may be significantly harmed.

We have initiated clinical trials for some of our solidproduct tumor programcandidates and we expect to submit additional IND applications for our solidcurrent tumor program.programs. However, we may not be able to file such IND application on the timelines we expect. For example, we may experience manufacturing delays or other delays with IND-enabling studies. Moreover, we cannot be sure that submission of an IND application will result in the FDA allowing clinical trials to begin, or that, once begun, issues will not arise that suspend or terminate clinical trials. Additionally, even if such regulatory authorities agree with the design and implementation of the clinical trials set forth in an IND application, we cannot guarantee that such regulatory authorities will not change their requirements in the future. These considerations also apply to new clinical trials we may submit as amendments to existing IND applications.

In addition, onewe ofare our key goals isplanning to develop treatments consisting of a combination of TCR-Ts, which we refer to as multiplex TCR-T therapy.TCR-T. Our plan is to assess the safety and preliminary efficacy of multiplex TCR-T therapy early in the clinical development of our product candidates. While our experience with our T-Plex IND shows that the FDA hasmay clearedclear our T-Plexan IND application, which allows us to combine our product candidates with each other in a multiplex TCR-T therapy,TCR-T, we must still provide safety data for each individual product candidate or each variation or combination of a multiplex TCR-T therapy.TCR-T. Any such requirements could result in material delays in the development timelines of our multiplex TCR-T therapy product candidates.

the patient eligibility criteria defined in the clinical trial protocol, particularly those who meet the requisite genetic criteria.criteria;

for our heme malignancies program, the ability to find a donor who must be mismatched with the patient either for the HLA type or the minor antigen type to ensure that the engineered T cell therapy does not recognize donor-derived blood cells;

risk that patients enrolled in clinical trials will drop out of the clinical trial or pass away from disease-related complications or complications from their standard clinical therapy before they can experience benefits of the engineered T cell therapy; and for patients in our solid tumor program, the patient's need for sufficient T cells in order for the engineered T cell product to be manufactured from their autologous T cells.

Research and development of biotechnology products is inherently risky. We may not be successful in our efforts to use and enhance our TScan technologytarget discovery platform and TCR technologies to create a pipeline of product candidates and develop commercially successful products, or we may expend our limited resources on programs that do not yield a successful product candidate and fail to capitalize on product candidates or diseases that may be more profitable or for which there is a greater likelihood of success. If we fail to develop additional product candidates, our commercial opportunity will be limited.

We are at an early stage of development and our TScan technologytarget discovery platform has not yet led, and may never lead, to approved or commercially successful products. All of our current product candidates are being developed by leveraging the same or similar underlying proprietary platform, manufacturing process and development program. As a result, an issue with one product candidate or failure of any one program to obtain regulatory approval could lead to a failure of our entire pipeline of product candidates.

Cancer therapies are sometimes characterized as first line, second line, or third line, and the FDA often approves new therapies initially only for a particular line of use. When cancer is detected early enough, first-line therapy is sometimes adequate to cure the cancer or prolong life without a cure. Whenever first-line,first-line therapy, usually chemotherapy, antibody drugs, tumor-targeted small molecules, hormone therapy, radiation therapy, surgery, or a combination of these, proves unsuccessful (refractory disease) or the cancer returns after a disease-free interval (relapsed disease), subsequent lines of therapy may be required to manage the disease and/or disease-related side-effects. We expect to initially seek approval for use of our TCR-T therapy product candidates to treat patients with heme malignancies, including acute myeloid leukemia,leukemia or(AML) AML,and myelodysplastic syndromes,syndromes or MDS, and acute lymphocytic leukemia, or ALL,(MDS) who are undergoing allogeneic HCT. While HCT provides a potentially curable option for patients with intermediate and high-risk disease, disease relapse remains the main cause of treatment failure and constitutes a significant unmet medical need. For our solid tumor product candidates, we expect to initially seek approval in patients with a history of relapsed disease or refractory disease. For those product candidates that prove to be sufficiently safe and beneficial, if any, we would expect to seek approval in earlier lines of therapy, as appropriate, but there is no guarantee that our product candidates would be licensed for an earlier line of therapy, and, prior to any such approvals, we may have to conduct additional clinical trials. Consequently, the potentially addressable patient population for our product candidates may be extremely limited or may not be amenable to treatment with our product candidates.

unexpected changes in tariffs (including tariffs that have been or may in the future be imposed by the United StatesU.S. or other countries), trade barriers (including further legislation or actions taken by the United StatesU.S. or other countries that restrict trade), price and exchange controls and other regulatory requirements;

Specifically, by genetically engineering T cell therapies, we face significant competition in the TCRT cell immunotherapy space from many companies. For additional information regarding our competition, see “Item 1. Business – Competition” in this Annual Report.Report on Form 10-K. Even if we obtain regulatory approval of our product candidates, the availability and price of our competitors’ products could limit the demand and the price we are able to charge for our product candidates. We may not be able to implement our business plan if the acceptance of our product candidates is inhibited by price competition or the reluctance of physicians to switch from existing methods of treatment to our product candidates, or if physicians switch to other new drug or biologic products or choose to reserve our product candidates for use in limited circumstances. Moreover, the development and manufacturing costs associated with engineered T cell therapies may make it difficult to compete with alternative products that may be simpler and cheaper to develop and manufacture.

Despite the implementation of security measures, our internal computer systems and those of our current and future CROs, our clinical sites, and other contractors and consultants are vulnerable, and like companies in our industry, we have experienced a variety of disruptions and data privacy and information security threats and incidents. These cyberattacks may include cybersecurity incidents, data breaches, attacks by hackers and other malicious third parties (including the deployment of computer viruses, malware, ransomware, denial-of-service attacks, social engineering fraud (including phishing attacks), and other events that affect service reliability and threaten the confidentiality, integrity, and availability of information), unauthorized access, natural disasters, fires, terrorism, war, telecommunications or electrical interruptions or failures, employee error or malfeasance or other malicious or inadvertent disruptions, including inadvertent or intentional wrongful actions by insider employees and vendors. For example, the ongoing conflict between Russia and Ukraine has led to an increase in cyberattacks on the Ukraine, including its government, companies, institutions and people, as well on the financial and communications infrastructure of other countries, companies and individuals therein. Additionally, the increased usage of computers operated on home networks may make our or our partners’ systems more susceptible to cybersecurity incidents or data breaches. While we have not experiencedIf any such material system failure, cybersecurity incident, or data breaches, if such a material eventbreach, were to occur and cause interruptions in our operations, it could result in a material disruption of our development programs and our business operations. For example, the loss of data from ongoing or completed or future preclinical studies and clinical trials could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data. Likewise, similar events relating to the computer systems of our third party vendors or manufacturers could also have a material adverse effect on our business, financial condition, results of operations and prospects. Bad actors around the world use increasingly sophisticated methods, including the use of artificial intelligence, to engage in illegal activities involving the theft and misuse of personal information, confidential information and intellectual property. In addition, the potential or current use of artificial intelligence models in our internal or third-party systems may create new attack surfaces or methods for adversaries, which could impact us and our vendors. Any of these effects could damage our reputation, result in the loss of valuable property and information, cause us to breach applicable laws and regulations, and adversely impact our business.

Manufacturing and administering our product candidates is complex and we may encounter difficulties in production, particularly with respect to process development or scaling up of our manufacturing capabilities. If we encounter such difficulties, our ability to provide supply of our TCR-T therapy product candidates for clinical trials oror, if approved, for commercial purposespurposes, could be delayed or stopped.

The process of manufacturing and administering our product candidates is complex and highly regulated. The manufacture of our product candidates involves complex processes, including the manufacture of a transposon containing the genetic information for our TCR construct, a transposase used to insert the transposon genetic information into the T cell genome, and manufacturing operations to ensure the safety, integrity, strength, sterility, purity, and quality of the final product. More specifically, the manufacture of our product candidates includes harvesting white blood cells from the patient, isolating certain T cells from the white blood cells, combining patient T cells with our delivery vector through a process known as transfection, selection of modified T cells from the population, expanding the selected transfected T cells to obtain the desired dose, aseptically filling product into vessels suitable for storage, distribution, and clinical dosing, and ultimately infusing the engineered T cells back into the patient’s body. As a result of the complexities entailed in this process, our manufacturing and supply costs may be higher than those of more traditional manufacturing processes and the manufacturing process may be less reliable and more difficult to reproduce. Additionally, the number of facilities that are capable of harvesting patients’ cells for the manufacture of our product candidates and other autologous cell therapy products and product candidates is limited. As the number of autologous cell therapy products and product candidates increases, the limited number of facilities capable of harvesting patients’ cells could result in delays in the manufacture and administration of our product candidates.

Our manufacturing process is and will be susceptible to product loss or failure due to logistical issues, manufacturing issues associated with the differences in patients’ white blood cells, interruptions in the manufacturing process or supply chain, contamination, equipment or reagent failure, process design flaws, operator error, power failures, supplier error and variability in patient characteristics. Even minor deviations from normal manufacturing processes could result in reduced production yields, product defects, product rejection, or other supply disruptions. If for any reason we lose a patient’s white blood cells, such material gets contaminated or processing steps fail at any point, the manufacturing process of the TCR-T therapy product candidate for that patient will need to be restarted, if possible, and the resulting delay may adversely affect thata patient’s outcome. If microbial, viral, or other contaminations are discovered in our product candidates or in the manufacturing facilities in which our product candidates or critical raw materials or reagents are made or administered, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination.

As our product candidates progress through preclinical studies and clinical trials towards licensure and commercialization, it is expected that various aspects of the manufacturing and administration process will be altered in an effort to optimize processes and results.results, for example, our efforts to develop an in vivo engineering platform for our solid tumor program. We have already identified some improvements to our manufacturing and administration processes, but these changes may not achieve the intended objectives, and could cause our product candidates to perform inadequately affecting the results of ongoing or future clinical trials. In addition, any changes may require amendments to be made to regulatory applications or necessitate development of new or additional TCR constructs and further clinical testing, which may further delay the timeframes under which modified manufacturing processes can be used for any of our product candidates.

We have limited experience as a company in setting up, building or managing a manufacturing facility or manufacturing suite, and may never be successful in managing our own manufacturing suite, manufacturing facility or manufacturing capability. We will need to hire additional personnel to manage our operations and facilities and develop the necessary infrastructure to continue the research and development, and eventual commercialization, if licensed, of our product candidates. If we fail to recruit the required personnel, manage our growth effectively, have inadequate facility design or construction, or fail to select the correct location, the development and production of our product candidates could be curtailed or delayed. Although we have established a manufacturing facility, our manufacturing capabilities could be affected by cost-overruns, unexpected delays, equipment failures, design or construction flaws, labor shortages, supply disruptions, natural disasters, power failures and numerous other factors that could prevent us from realizing the intended benefits of our manufacturing strategy and have a material adverse effect on our business.

We plan tomay seek approval of our current product candidates and may seek approval ofor future product candidates using the FDA’s Accelerated Approval pathway. A product may be eligible for Accelerated Approval if it treats a serious or life-threatening condition and generally provides a meaningful advantage over available therapies. In addition, it must demonstrate an effect on a surrogate endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality (IMM) that is reasonably likely to predict an effect on IMM or other clinical benefit. As a condition of approval, the FDA may require that a sponsor of a drug or biologic receiving Accelerated Approval perform adequate and well-controlled post-marketing clinical trials. These confirmatory trials must be completed with due diligence. In addition, the FDA currently requires, unless otherwise informed by the agency, pre-approval of promotional materials for products receiving Accelerated Approval, which could adversely impact the timing of the commercial launch of the product. Even if we do receive Accelerated Approval, we may not experience a faster development, regulatory review or approval process for that product. In addition, receiving Accelerated Approval does not provide assurance of ultimate FDA approval.

We may seek designation for our TargetScantarget discovery platform as a designated platform technology, but we might not receive such designation, and even if we do, such designation may not lead to a faster regulatory review or approval process.

We may seek designation for our TargetScantarget discovery platform as a designated platform technology. Under the Food and Drug Omnibus Reform Act of 2022 (FDORA), a platform technology incorporated within or utilized by a biological product is eligible for designation as a designated platform technology if (1) the platform technology is incorporated in, or utilized by, a biological product approved under a BLA; (2) preliminary evidence submitted by the sponsor of the licensed biological product, or a sponsor that has been granted a right of reference to data submitted in the application for such biological product, demonstrates that the platform technology has the potential to be incorporated in, or utilized by, more than one biological product without an adverse effect on quality, manufacturing, or safety; and (3) data or information submitted by the applicable person indicates that incorporation or utilization of the platform technology has a reasonable likelihood to bring significant efficiencies to the biological product development or manufacturing process and to the review process. A sponsor may request the FDA to designate a platform technology as a designated platform technology concurrently with, or at any time after, submission of an IND application for a biological product that incorporates or utilizes the platform technology that is the subject of the request. If so designated, the FDA may expedite the development and review of any subsequent original BLA for a biological product that uses or incorporates the platform technology. Even if we believe our TargetScantarget discovery platform technology meets the criteria for such designation, the FDA may disagree and instead determine not to grant such designation. In addition, the receipt of such designation for a platform technology does not ensure that a biological product will be developed more quickly or receive FDA approval. Moreover, the FDA may revoke a designation if the FDA determines that a designated platform technology no longer meets the criteria for such designation.

The regulations that govern marketing approvals, pricing, coverage and reimbursement for new drugs vary widely from country to country. In the U.S., recently enacted legislation may significantly change the approval requirements in ways that could involve additional costs and cause delays in obtaining approvals. Some countries require approval of the sale price of a drug before it can be marketed. In many countries, the pricing review period begins after marketing or product licensing approval is granted. In some foreign markets, prescription pharmaceutical pricing remains subject to continuing governmental control even after initial approval is granted. As a result, we might obtain marketing approval for a product in a particular country, but then be subject to price regulations that delay our commercial launch of the product, possibly for lengthy time periods, and negatively impact the revenue we are able to generate from the sale of the product in that country. Adverse pricing limitations may hinder our ability to recoup our investment in one or more product candidates, even if any product candidates we may develop obtain marketing approval. For more information, please see “Item 1. Business – Government Regulation – Coverage and Reimbursement” in this Annual Report.Report on Form 10-K.

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 U.S. 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,price or ASP,(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.

Our revenue prospects could be affected by changes in healthcare spending and policy in the U.S. and abroad. We operate in a highly regulated industry and new laws, regulations or judicial decisions, or new interpretations of existing laws, regulations or decisions, related to healthcare availability, the method of delivery or payment for healthcare products and services could negatively impact our business, operations and financial condition. For more information on healthcare laws and regulations that may impact us, please see “Item 1. Business – Government Regulation – Healthcare Legislative Reform” in this Annual Report.Report on Form 10-K.

Regulatory requirements in the U.S. and abroad governing cell therapy products have changed frequently and may continue to change in the future. The FDA has established an office, called the Office of Therapeutic Products within its Center for Biologics Evaluation and Research to meet its growing cell and gene therapy workload. The FDA also established the Cellular, Tissue and Gene Therapies Advisory Committee to advise its review. Under guidelines issued by the National Institutes of Health,Health or NIH,(NIH) certain gene therapy clinical trials are subject to review and oversight by an institutional biosafety committee,committee or IBC,(IBC) a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. Before such a clinical trial can begin, the institution’s institutional review board,board or IRB,(IRB) and its IBC assess 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.

Inadequate funding for the FDA, the SEC and other government agencies could hinder their ability to hire and retain key personnel, and substantial changes in leadership, personnel, organizational structure, and policy could prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of our business may rely, 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 staffing, government budget and funding levels, the FDA’s ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes.changes, 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. For example, over the last several years the U.S. government has shut down several times and certain regulatory agencies, such as the FDA and the SEC, in some instances have had to furlough critical FDA, SEC and other government employees and stop critical activities.

Disruptions at the FDA and other agencies, including substantial leadership,leadership personnel,departures and changes, personnel cuts and policy changes, may also slow the time necessary for new drugs to be reviewed and/or approved by necessary government agencies,approved, which would adversely affectharm our business. ForChanges example,and overcuts in FDA staffing also could result in delays in the lastFDA’s severalresponsiveness yearsor thein U.S.its governmentability hasto shutreview, downor severalconsistency timesin and certainreviewing, regulatory agencies,submissions suchor asapplications, theissue FDAregulations andor theguidance, SEC,or haveimplement hador toenforce furloughregulatory criticalrequirements FDA,in SECa andtimely otherfashion governmentor employeesat and stop critical activities.all. If a prolonged government shutdown or substantial leadership, personnel, and policy changes occur, 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, in our operations as a public company, 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. Such changes could significantly impact the ability of the FDA to timely review and take action on our regulatory submissions, which could have a material adverse effect on our business. Further, in our operations as a public company, future government shutdowns or substantial leadership, personnel, and policy changes could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

With the change in the U.S. presidential administration in 2025, there is substantial uncertainty as to whetherthe extent and nature of how the newTrump administration will seek to modify or revise the requirements and policies of the FDA and other regulatory agencies with jurisdiction over our product candidates. This uncertainty could present new challenges and/or opportunities as we navigate development of our product candidates. Additionally, the Trump administration could issue or promulgate executive orders, regulations, policies or guidance that adversely affect us or create a more challenging or costly environment to pursue the development of new product candidates. Any delay in obtaining, or our inability to obtain, applicable regulatory approvals would delay or prevent development and commercialization of our product candidates and could materially adversely impact our business and prospects.

We are exposed to the risk of employee fraud or other illegal activity by our employees, independent contractors, consultants, commercial partners and vendors. Misconduct by these parties could include intentional, reckless and/or negligent conduct that fails to: comply with the regulations of the FDA and other similar foreign regulatory authorities, provide true, complete and accurate information to the FDA and other similar foreign regulatory authorities, comply with manufacturing standards we have established, comply with healthcare fraud and abuse laws in the U.S. and similar foreign fraudulent misconduct laws or report financial information or data accurately or to disclose unauthorized activities to us. If we obtain FDA approval of any of our product candidates and begin commercializing those products in the U.S., our potential exposure under such laws and regulations will increase significantly, and our costs associated with compliance with such laws and regulations are also likely to increase. These laws may impact, among other things, our current activities with principal investigators and research patients, as well as proposed and future sales, marketing and education programs. In particular, the promotion, sales and marketing of healthcare items and services, as well as certain business arrangements in the healthcare industry, are subject to extensive laws designed to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, structuring and commission(s), certain customer incentive programs and other business arrangements generally. Activities subject to these laws also involve the improper use of information obtained in the course of patient recruitment for clinical trials. For more information, please see “Item 1. Business – Government Regulation – Anti-Kickback and False Claims Laws and Other Regulatory Matters” in this Annual Report.Report on Form 10-K.

In the U.S., various federal and state regulators, including governmental agencies like the Federal Trade Commission, have adopted, or are considering adopting, laws and regulations concerning personal information and data security. Certain state laws may be more stringent or broader in scope, or offer greater individual rights, with respect to personal information than federal, international or other state laws, and such laws may differ from each other, all of which may complicate compliance efforts. For example, the California Consumer Privacy Act (CCPA) asestablished amended by the California Privacy Rights Act (CPRA) created individualnew privacy rights for California residents and imposedintroduced obligationsnew on covered companies that process their personal information andof meetCalifornia certain revenue or volume processing thresholds.residents. Among other things, the CCPA requires covered companies to provide certain disclosures to California residents and provide such residents with new data protection and privacy rights, including the ability to opt-out of certain sales of personal information. The amendments introduced by the California Privacy Rights Act (CPRA) significantly modified the CCPA by expanding residents’ rights with respect to certain personal information and created a new state agency to oversee implementation and enforcement efforts, among other changes. The CCPA provides for civil penalties for violations, as well as a private right of action for certain data breaches. This private right of action may increase the likelihood of, and risks associated with, data breach litigation, including class action litigation.

Significantly, the GDPR imposes strict rules on the transfer of personal data out of the EEA and UK to other regions outside the EEA/UK, or third countries, that have not been deemed to offer “adequate” privacy protections by the competent data protection authorities, including the U.S. in certain circumstances, unless a derogation exists or adequate international transfer safeguards are put in place, such as, for example, the European Commission approved Standard Contractual Clauses (the EU SCCs) and the UK International Data Transfer Agreement/Addendum (the UK IDTA). Where relying on the EU SCCs or UK IDTA for data transfers, we may also be required to carry out transfer impact assessments on the transfers made pursuant to the EU SCCs and UK IDTA, on a case-by-case basis, to ensure the law in the recipient country provides “essentially equivalent” protections to safeguard the transferred personal data as provided in the EEA and UK, and may be required to adopt supplementary measures if this standard is not met. Further, the EU and the U.S. have adopted its adequacy decision for the EU-U.S. Data Privacy Framework ("Framework"), which entered into force on July 11, 2023. This Framework provides that the protection of personal data transferred between the EU and the U.S. is comparable to that offered in the EU. This provides a further avenue to ensuring transfers to the U.S. are carried out in line with GDPR. There has been an extension to the Framework to cover UK transfers to the U.S. The Framework could be challenged like its predecessor frameworks. The international transfer obligations under the EEA and UK data protection regimes will require significant effort and cost and may result in us needing to make strategic considerations around where EEA and UK personal data is located and which service providers we can utilize for the processing of EEA and UK personal data. Any inability to transfer personal data from the EEA to the U.S. in compliance with data protection laws may impede our ability to conduct trials and may adversely affect our business and financial position.

Although the UK is regarded as one of the third countries under the EU GDPR, the European Commission has adopted an adequacy decision in favor of the UK, enabling data transfers from EEA member states to the UK without additional safeguards. TheIn UKDecember government2025, hasthe confirmedEuropean thatCommission personaladopted dataa transfersdecision fromto extend the validity of the UK toadequacy thedecision EEAfor remainsix freeyears flowing.until TheDecember UK2031, Governmentdetermining introduced the Data Protection and Digital Information Bill which failed inthat the UK legislativecontinues process.to Aoffer newa level of data protection that is “essentially equivalent” to the EU standards. This follows the UK’s adoption of the Data (Use and Access) BillAct 2025 on 19 June 2025.. The Data (UKUse Billand Access) hasAct now been introduced into parliament. If passed, the final version of the UK Bill2025 may have the effect of further altering the similarities between the UK and EEA data protection regime. Further, this may lead to additional compliance costs and could increase our overall risk. Further, theThe competent authorities in the EEA Member States may interpret GDPR obligations slightly differently from country to country and therefore we do not expect to operate in a uniform legal landscape in the EEA.

We are advancinga fully integrated clinical-stage biotechnology company focused on developing a robust pipeline of TCR-TT therapycell productreceptor candidates(TCR)-engineered T cell, or TCR-T, therapies for the treatment of patients with heme malignancies and solid tumors.cancer. Our lead product candidates, TSC-100 andcandidate, TSC-101, areis in development for the treatment of patients with acute myeloid leukemia (AML), and myelodysplastic syndrome (MDS), and acute lymphoblastic leukemia (ALL), who are undergoing allogeneic hematopoietic cell transplantation (HCT). The productsproduct areis designed to eliminate residual disease and promote complete donor chimerism, thereby preventing relapse. TSC-100 and TSC-101 target the antigens HA-1 andtargets HA-2, respectively,an which are well-recognized TCR targetsantigen that wereis firstpresent identifiedon all blood cells, malignant or benign, in patients with exceptionalthe responsesHLA totype HCT-associated immunotherapy.A*02:01. We are currently conducting a multi-arm Phase 1 "umbrella" clinical study of TSC-100TSC-101 and TSC-101, (the ALLOHA™ trial, NCT05473910) and during the fourth quarter of 2025, following a productive End-of-Phase meeting with the U.S. Food and Drug Administration (FDA), we reached agreement on a registrational path forward for the TSC-101 program as a potential treatment for patients with AML and MDS. The pivotal study will mirror our ongoing Phase 1 hemeALLOHA trial,study, withusing 15a clinicalbiologically-assigned sites(genetically activated,randomized) andcontrol we planarm to opensupport additionalrelapse-free sitessurvival beforeas the endprimary of 2025.endpoint.

In addition, weWe are also developing multiple TCR-T therapy product candidates for the treatment of solid tumors. One of the challenges of treating solid tumors is that they are heterogeneous – not every tumor cell expresses a given target and some tumor cells lose half their HLA genes.target. To address this challenge, we are developing what we refer to as multiplex TCR-T therapy, or T-Plex, in which we treat a patient with more than one TCR-T therapy product candidate at a time. We are designing these multiplex therapies to be a simultaneous administration of up to three highly active TCR-T therapy product candidates, selected from our ImmunoBank,TCR-Ts that are customized for each patient based on which targets are expressed in their tumorstumors. andOn whichNovember HLA3, genes2025, arefollowing stillour intact. We continue to prioritize expanding the ImmunoBankalignment with TCRs for additional targets and multiple HLA types for each target. We have now advanced seven TCR-T therapy product candidates into Phase 1 development for solid tumors: TSC-203-A0201 (PRAME, HLA-A*02:01); TSC-200-A0201 (HPV16, HLA-A*02:01); TSC-201-B0702 (MAGE-C2, HLA-B*07:02); TSC-202-A0201 (MAGE-A4, HLA-A*02:01); TSC-204-A0201 (MAGE-A1, HLA-A*02:01); TSC-204-C0702 (MAGE-A1, HLA-C*07:02); and TSC-204-A0101 (MAGE-A1, HLA-A*01:01). In addition to clearing these seven solid-tumor investigational new drug (IND) applications, the U.S. Food and Drug Administration (FDA) hason clearedthe registrational path forward for the TSC-101 program, we made the strategic decision to prioritize clinical development of our INDheme applicationprogram and pause further enrollment in our solid tumor Phase 1 trial (PLEXI-T™), while focusing our preclinical efforts on in vivo engineering for T-Plex,solid enablingtumors. usWe believe an in vivo approach represents a promising and more cost-efficient way to treatdeliver patientsoff-the-shelf, with multiplex TCR-T therapy. We plan to further expand the ImmunoBank by filing IND applications for additionalmultiplexed TCR-T therapy product candidates. We have initiated a Phase 1for solid tumor clinical trial, the PLEXI-T™ trial, with 15 clinical sites activated, and we plan to open additional sites before the end of 2025.tumors.

To date, our revenue has primarily been derived from our collaboration and licensing agreements, which have been in the scope of ASC 606, Revenue from Contracts with Customers. We have not generated any revenue from the sale of therapies to date, nor do we expect to generate revenues therefrom in the near future, if at all. If our development efforts for our product candidates are successful and result in regulatory approval or if we enter into additional license or collaboration agreements with third parties, we may generate additional revenue in the future from sales of our therapies, payments from license or collaboration agreements that we may enter into with third parties, or any combination thereof. However, there can be no assurance as to when we will generate such revenue, if at all. We expect that our revenue for at least the next several years will be derived primarily from collaborations and licenses that we may enter into in the future, if any.

Product candidates in later stages of clinical development generally have higher development costs than those in preclinical and earlier stages of clinical development, primarily due to increased size and duration of later stage clinical trials. We expect that our research and development expenses will increase substantially in connection with our planned preclinical and clinical development activities in the near term and in the future. At this time, we cannot accurately estimate or know the nature, timing and costs of the efforts that will be necessary to complete the preclinical and clinical development of any of our product candidates. The successful development and commercialization of our product candidates is highly uncertain. This is due to the numerous risks and uncertainties associated with therapeutic development and commercialization, including the following:

Revenue for the years ended December 31, 20242025 and 20232024 was $2.8$10.3 million and $21.0$2.8 million, respectively. The decreaseincrease was primarily due to the timing of research activities performed pursuant to our collaboration agreements. Revenue for the 2024 period was related solely to our collaboration agreement with Amgen which commenced in May 2023. Revenue for the 2023 period was primarily driven by $14.2 million related to our collaboration agreement with Amgen, and $5.8 million related to our collaboration agreement with Novartis, which concluded in March 2023.

General and administrative expenses increased by $3.9$1.7 million and was primarily due to a $1.8$0.5 million increase in personnel expenses due to additional headcount.expenses. There was also a $0.3$0.4 million increase in facility-related and other expenses, a $0.2 million decrease in legal and professional fees, a $0.4 million decrease in facility-related expenses, and a $0.1 million decrease in depreciation expense. General and administrative expenses included non-cash stock compensation expense of $4.7$5.7 million and $2.3$4.7 million for the years ended December 31, 20242025 and 2023,2024, respectively.

Other income hasdecreased increased $3.1$1.3 million primarily due to a $4.1$3.2 million increasedecrease in interest income attributable to higherlower cash balances available for investment,investment. This decrease was offset by a $1.1 million non-recurring charge for loss on extinguishment of debt in 2024 related to the K2HV Loan Agreement repayment.repayment and a $0.9 million decrease in interest expense due to more favorable rates in 2025 under the SVB Loan Agreement.

On June 1, 2023, we completed an underwritten public offering of (a) 23,287,134 shares of the Company's Voting Common Stock, inclusive of the underwriters’ 30-day option to purchase 297,660 additional shares of Voting Common Stock, at a price of $2.00 per share, and (b) the Pre-Funded Warrants to purchase up to 47,010,526 shares of the Voting Common Stock, atwith a purchase price of $1.9999 per warrant withand an exercise price of $0.0001 per share.warrant. The Company received aggregate net proceeds from the offering of $134.7 million after deducting underwriting discounts, commissions and other offering expenses.

On April 24, 2024, we completed an underwritten public offering resulting in the issuance and sale of (a) 4,958,068 shares of Voting Common Stock, including the partial exercise of the underwriters’ option to purchase 2,485,487 additional shares of Voting Common Stock, at the closing market price on April 16, 2024, of $7.13 per share, and (b) Pre-Funded Warrants to purchase up to 18,577,419 shares of the Voting Common Stock, atwith a purchase price of $7.1299 per warrant withand an exercise price of $0.0001 per share.warrant. We received aggregate net proceeds of approximately $161.4 million after deducting underwriting discounts, commissions and other estimated offering expenses.

Pursuant to the K2HV Loan Agreement dated September 9, 2022, K2HV extended an initial convertible term loan of $30.0 million to the Company in accordance with the K2HV Loan Agreement. On November 20, 2024, K2HV converted $15.0 million outstanding principal under the loan in exchange for 3,134,796 shares of our voting common stock. On December 20, 2024, we entered into a loan agreement with SVB (the SVB Loan Agreement), terminated the K2HV Loan Agreement and repaid all remaining outstanding loan obligations to K2HV. The SVB Loan Agreement provides for term loans up to an aggregate principal amount of $52.5 million, of which $32.5 million was provided on the closing date. We have the option to draw a second tranche of $20.0 million at the lender's sole discretion on or prior to June 30, 2026. See “Notes to Condensed Consolidated Financial Statements” and “Item 1A. Risk factors—The terms of our loan agreement place restrictions on our operating and financial flexibility. If we raise additional capital through debt financing, the terms of any new debt could further restrict our operating and financial flexibility” for additional details regarding the SVB Loan Agreement.

As of December 31, 2024,2025, we had cash,cash and cash equivalents and marketable securities of $290.1$152.4 million, excluding restricted cash of $5.0 million.

We believe that our existing cash,cash and cash equivalents and marketable securities will enable us to fund our planned operating expenses and capital expenditure requirements into the firstsecond quarterhalf of 2027. We have based this estimate on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we expect.

During the yearsyear ended December 31, 2024 and 2023,2025, net cash usedprovided inby investing activities was $52.6 million and $60.8$109.4 million, respectively, primarily related to the purchases of property and equipment, and purchases and maturities of marketable securities.securities, and the purchases of property and equipment.

Investing in our common stock involves a high degree of risk. You should consider carefully the risks and uncertainties described below, together with all of the other information in this Quarterly Report on Form-10-Q,Form 10-Q, and in other documents that we file with the SEC. The risks and uncertainties described below are not the only ones we face. Additional risks and uncertainties that we are unaware of or that we deem immaterial may also become important factors that adversely affect our business. If any of the following risks actually occur, our business, financial condition, liquidity, operating results, and prospects could be materially and adversely affected.

We have incurred significant net losses in each period since our inception in April 2018. For the three and six months ended MarchJune 31,30, 2026 and the years ended December 31, 2025 and 2024, we reported net losses of $28.7$30.4 million, $59.0 million, $129.8 million, and $127.5 million, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $533.5$563.9 million. We expect to continue to incur significant losses for the foreseeable future, and we expect these losses to increase substantially if and as we:

In addition, the success of our proprietary platform in discovering novel targets for TCR-T therapy product candidates is dependent on us obtaining tumor samples from cancer patients who actively respond to cancer immunotherapies. If our ability to obtain a significant amount of such tumor samples in a timely manner is compromised due to unforeseen circumstances, we may not be successful in discovering novel targets and creating new product candidates based on such targets.targets

As of MarchJune 31,30, 2026, we had $128.1$100.2 million in cash and cash equivalents. We believe that our existing cash and cash equivalents will enable us to fund our current operating plan into the second halfquarter of 2027. Accordingly, our existing cash and cash equivalents will not be sufficient for us to fund any of our product candidates through regulatory approval, and we will need to raise substantial additional capital to complete the development and commercialization of our product candidates through equity offerings, debt financings, marketing and distribution arrangements and other collaborations, strategic alliances and licensing arrangements or other sources. We may also need to raise additional funds sooner if we choose to pursue additional indications for our product candidates or otherwise expand more rapidly than we presently anticipate.

On December 20, 2024 (the SVB Loan Effective Date), we entered into a Loan and Security Agreement (SVB Loan Agreement) with Silicon Valley Bank, a division of First-Citizens Bank & Trust Company (SVB), pursuant to which, SVB will extend up to $52.5 million in a term loan facility, of which $32.5 million was fully funded at the SVB Loan Effective Date. A second tranche of $20.0 million maywas beavailable fundedto us at SVB’s sole discretion on or prior to June 30, 2026. We did not draw the second tranche prior to June 30, 2026, and the second tranche is no longer available. Our obligations under the SVB Loan Agreement, are secured by a first-priority security interest on substantially all of our assets (other than intellectual property), subject to certain exceptions and will be guaranteed by each of our future direct or indirect subsidiaries, subject to certain exceptions. The SVB Loan Agreement contains customary representations and warranties, events of default and affirmative and negative covenants, including covenants that limit or restrict our and our subsidiaries’ ability to, among other things, dispose of assets, make changes to its business, management, ownership or business locations, merge or consolidate, incur additional indebtedness, grant liens on its assets, pay dividends or other distributions, repurchase equity, make investments, and enter into certain transactions with affiliates, in each case subject to certain thresholds and exceptions. The SVB Loan Agreement does not require us to comply with a financial maintenance covenant. Upon the occurrence of an event of default, a default interest rate of an additional 3% may be applied to the outstanding loan balance at the sole discretion of SVB and SVB may declare all outstanding obligations immediately due and payable and exercise all of its rights and remedies as set forth in the SVB Loan Agreement and under applicable law. Any declaration by SVB of an event of default could significantly harm our business and prospects and could cause the price of our common stock to decline. We may not have enough available cash or be able to raise additional funds through equity or debt financings to repay these outstanding obligations at the time any event of default occurs. Further, if we raise any additional capital through debt financing, the terms of such additional debt could further restrict our operating and financial flexibility.

On November 3, 2025, the Company announced a prioritization strategy and pursuant to this strategy, the Company also implemented a workforce reduction of approximately 30%, or 66 roles. The workforce reduction thathas will accompany our prioritization strategy will resultresulted in the loss of longer-term employees, the loss of certain institutional knowledge and expertise and the reallocation and combination of certain roles and responsibilities across the organization, all of which could adversely affect our operations. The restructuring and possible additional cost containment measures may yield unintended consequences, such as attrition beyond our intended workforce reduction and reduced employee morale. In addition, we may not achieve anticipated benefits from the workforce reduction. Due to our limited resources, we may not be able to effectively manage our operations or recruit and retain qualified personnel, which may result in weaknesses in our infrastructure and operations, further loss of employees and reduced productivity among remaining employees. If our management is unable to effectively manage this transition and workforce reduction and additional cost containment measures, our expenses may be more than expected and we may not be able to implement our business strategy. As a result, our future financial performance and our ability to commercialize our future product candidates successfully could be negatively affected.

For example, we are planning a registrational trial for TSC-101, and based on feedback from regulatory authorities, we may need to modify our clinical trial design or may be delayed in initiating such trial. If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not positive or are only moderately positive or if there are safety concerns, our business and results of operations may be adversely affected and we may incur significant additional costs. Accordingly, our clinical trial costs are likely to be significantly higher than those for more conventional therapeutic technologies or drug product candidates.

We have established facilities and engaged third-party contract manufacturers to manufacture our current product candidates. We rely on outside vendors to manufacture supplies for our manufacturing process, and we expect to rely on outside vendors to help us manufacture our product candidates for registration-enabling additional clinical trials as well as commercial sales. We have not yet manufactured or processed any product candidates on a commercial scale and may not be able to do so. We planhave to optimizeoptimized the existing manufacturing process to support product commercialization. The process modifications we intendhave to introduceintroduced will require regulatory approval of our product candidates, which could delay the commercialization of the products. We cannot be sure that such changes in the process will result in therapies that are efficacious and viable for commercial sale. In addition, changes in the manufacturing process may result in the need to conduct additional bridging clinical trials to demonstrate product comparability.

Undesirable side effects caused by our product candidates could cause us or regulatory authorities, including IRBs, 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 authorities. Further, clinical trials by their nature utilize a sample of the potential patient population. With a limited number of subjects and limited duration of exposure, rare and severe side effects of our product candidates may only be uncovered with a significantly larger number of patients exposed to the drug. Because of the design of the dose escalation of our planned Phase 1 clinical trials, undesirable side effects could also result in an expansion in the size of our clinical trials, increasing the expected costs and timeline of our clinical trials. Additionally, results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects or unexpected characteristics, which may stem from our therapies specifically or may be due to an illness from which the clinical trial subject is suffering.

Autoimmune reaction triggered by an interaction between a patient’s naturally occurring antibodies and engineered T cells is a theoretical safety risk of product candidates we develop using our proprietary platform. If a patient’s self-generated antibodies were directed to a target expressed on the surface of cells in normal tissue (autoantibodies), engineered T cells would be directed to attack these same tissues, potentially resulting in off-tumor effects. These autoantibodies may be present whether or not the patient has an active autoimmune disorder. In our clinical testing, we plan to take steps to minimize the likelihood that this occurs, for example by excluding patients with a history of a severe autoimmune disorder from our trials.occurs. There is no guarantee, however, that we will be able to implement interventions to address the risk of autoimmune reactions if and when they occur.

There have been, and likely will continue to be, legislative and regulatory proposals at the foreign, federal and state levels directed at broadening the availability of healthcare and containing or lowering the cost of healthcare. We cannot predict the initiatives that may be adopted in the future, including repeal, replacement or significant revisions to the Affordable Care Act.Act and drug pricing reforms. The continuing efforts of the government, insurance companies, managed care organizations and other payors of healthcare services to contain or reduce costs of healthcare and/or impose price controls may adversely affect:

In the U.S., various federal and state regulators, including governmental agencies like the Federal Trade Commission, have adopted, or are considering adopting, laws and regulations concerning personal information and data security. Certain state laws may be more stringent or broader in scope, or offer greater individual rights, with respect to personal information than federal, international or other state laws, and such laws may differ from each other, all of which may complicate compliance efforts. For example, the California Consumer Privacy Act (CCPA) established new privacy rights for California residents and introduced new onfor covered companies that process their personal information of California residents.information. Among other things, the CCPA requires covered companies to provide certain disclosures to California residents and provide such residents with new data protection and privacy rights, including the ability to opt-out of certain sales of personal information. The amendments introduced by the California Privacy Rights Act (CPRA) significantly modified the CCPA by expanding residents’privacy rights with respect to certain personal information and created a new state agency to oversee implementation and enforcement efforts, among other changes. The CCPA provides for civil penalties for violations, as well as a private right of action for certain data breaches. This private right of action may increase the likelihood of, and risks associated with, data breach litigation, including class action litigation.litigation and regulatory enforcement.

Similar laws have been passed in numerous other states and a number of other states have proposed new privacy laws, some of which are similar to the above discussed recently passed laws. 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 existence of comprehensive privacy laws in different states in the country would make our compliance obligations more complex and costly and may increase the likelihood that we may be subject to enforcement actions or otherwise incur liability for noncompliance. In addition, laws in all 50 U.S. states require businesses to provide notice to individuals if certain of their personal information has been disclosed as a result of a qualifying data breach. There are also states that are specifically regulating health information. For example, Washington’s My Health My Data Act. The My Health My Data Act imposes new state restrictions and requirements on the processing and sale of consumer health data and creates a private right of action, which further increases the relevant compliance risk. Connecticut and Nevada have also passed similar laws regulating consumer health data. In addition, other states have proposed and/or passed legislation that regulates the privacy and/or security of certain specific types of information. For example, a small number of states have passed laws that regulate biometric data specifically. These various privacy and security laws may impact our business activities, including our identification of research subjects, relationships with business partners and ultimately the marketing and distribution of our products. State laws are changing rapidly and therecompliance isrequirements discussionand inenforcement theremains U.S. Congress of a new comprehensive federal data privacy law to which we may likely become subject, if enacted.unpredictable.

our contract manufacturers may have unacceptable or inconsistent product quality success rates and yields, and we have no direct control over our contract manufacturers’ ability to maintain adequate quality control, quality assurance and qualified personnel; and our contract manufacturers may be adversely affected by the geopolitical and economic tensions in the Middle East and with China, the ongoing conflicts between Russia and Ukraine, political unrest in countries where we or our partners operate, earthquakes, flooding, fires, and other natural or man-made disasters, equipment failures, labor shortages, power failures, and numerous other factors.

The manufacture of cellular-based drug products is complex and requires significant expertise and capital investment, including the development of advanced manufacturing techniques and process controls. Manufacturers of such products often encounter difficulties in production, particularly in scaling up or out, validating the production process and assuring high reliability of the manufacturing process (including the absence of contamination). These problems include logistics and shipping, difficulties with production costs and yields, quality control, including stability of the product, intermediates, or raw materials, product testing, operator error and availability of qualified personnel, as well as compliance with strictly enforced federal, state and foreign regulations. Furthermore, if contaminants are discovered in our supply of our product candidates or in the manufacturing facilities, such manufacturing facilities may need to be closed for an extended period of time to investigate and remedy the contamination. We cannot provide assurance that any stability failures or other issues relating to the manufacture of our product candidates will not occur in the future.

As of MayAugust 1,7, 2026, we had 138 full-time employees and 1 part-time employee.employees. As our development and commercialization plans and strategies develop, and as we continue operating as a public company, we expect to need additional managerial, operational, sales, marketing, financial and other personnel, as well as additional facilities to expand our operations. Future growth would impose significant added responsibilities on members of management, including:

the economy as a whole and market conditions in our industry, including conditions resulting from ongoing conflicts in the Middle East and between Russia and Ukraine;

As of MayAugust 1,7, 2026, our executive officers, directors, and entities affiliated with such persons beneficially owned, in the aggregate, approximately 25%24% of our outstanding voting stock and approximately 30%29% of our outstanding common stock. As a result, these stockholders, acting together, have significant influence over all matters that require approval by our stockholders, including the election of directors and approval of significant corporate transactions. Corporate actions might be taken even if other stockholders, oppose them. This concentration of ownership may prevent or discourage unsolicited acquisition proposals or offers for our common stock that you or other stockholders may feel are in your or their best interest as one of our stockholders. This concentration of ownership might also have the effect of delaying or preventing a change of control of our Company that other stockholders may view as beneficial.

Effective internal controls over financial reporting are necessary for us to provide reliable financial reports and, together with adequate disclosure controls and procedures, are designed to prevent fraud. Any failure to implement required new or improved controls, or difficulties encountered in their implementation could cause us to fail to meet our reporting obligations. In addition, any testing by us conducted in connection with the Sarbanes-Oxley Act or any subsequent testing by our independent registered public accounting firm, may reveal deficiencies in our internal controls over financial reporting that are deemed to be material weaknesses or that may require prospective or retroactive changes to our financial statements or identify other areas for further attention or improvement. Inferior internal controls could also cause investors to lose confidence in our reported financial information, which could have a negative effect on the trading price of our stock We are required to disclose changes made in our internal controls and procedures on a quarterly basis and our management will be required to assess the effectiveness of these controls annually. However, for as long as we are an “emerging growth company” under JOBS Act, our independent registered public accounting firm will not be required to attest to the effectiveness of our internal controls over financial reporting pursuant to the Sarbanes-Oxley Act. We would cease to be an emerging growth company on the date that is the earliest of (i) the last day of the fiscal year in which we have total annual gross revenue of $1.235 billion or more; (ii) December 31, 2026; (iii) the date on which we have issued more than $1.0 billion in nonconvertible debt during the previous three years; or (iv) the last day of the fiscal year in which we are deemed to be a large accelerated filer under the rules of the SEC, which means the market value of our voting and non-voting common stock that is held by non-affiliates exceeds $700 million as of the prior June 30th. An independent assessment of the effectiveness of our internal controls over financial reporting could detect problems that our management’s assessment might not. Undetected material weaknesses in our internal controls over financial reporting could lead to financial statement restatements and require us to incur the expense of remediation.

the changing and volatile U.S., European and global economic environments; and future accounting pronouncements or changes in our accounting policies The cumulative effects of these factors could result in large fluctuations and unpredictability in our quarterly and annual operating results. As a result, comparing our operating results on a period-to-period basis may not be meaningful. This variability and unpredictability could also result in our failing to meet the expectations of industry or financial analysts or investors for any period. If our revenue or operating results fall below the expectations of analysts or investors or below any forecasts we may provide to the market, or if the forecasts we provide to the market are below the expectations of analysts or investors, the price of our common stock could decline substantially. Such a stock price decline could occur even when we have met any previously publicly stated guidance we may provide.

We are a fully integrated clinical-stage biotechnology company focused on developing a robust pipeline of T cell receptor (TCR)-engineered T cell, or TCR-T, therapies for the treatment of patients with cancer. Our lead product candidate, TSC-101, is in development for the treatment of patients with acute myeloid leukemia (AML) and myelodysplastic syndromesyndromes (MDS) who are undergoing allogeneic hematopoietic cell transplantation (HCT). The product is designed to eliminatetreat residual disease post-HCT and promote complete donor chimerism, thereby preventingprevent relapse. TSC-101 targets HA-2, an antigen that is present on all blood cells, malignant or benign, in patients with the HLA type A*02:01. We are currently conducting a Phase 1 clinical study of TSC-101 (the ALLOHA™ trial, NCT05473910) and during the fourth quarter of 2025, following a productive End-of-Phase meeting with the U.S. Food and Drug Administration (FDA), we reached agreement on a registrational path forward for the TSC-101 program as a potential treatment for patients with AML and MDS. The pivotal study will mirror our ongoing Phase 1 ALLOHA study, using a biologically-assigned (genetically randomized) control arm to support relapse-free survival as the primary endpoint.

We are further expanding our hematologic (heme) malignancies program with the addition of TCRs targeting other HLA types. TSC-102-A01 and TSC-102-A03 are allogeneic, donor-derived TCR-T therapy candidates targeting epitopes derived from CD45. Like TSC-101, these candidates are designed to eliminate residual cancer cells and prevent relapse in patients undergoing HCT. TSC-102-A01 and TSC-102-A03 are designed for patients with HLA types A*01:01 and A*03:01, respectively.

We have incurred significant operating losses since our inception. We reported net losses of $28.7$59.0 million and $34.1$71.1 million for the threesix months ended MarchJune 31,30, 2026 and 2025, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $533.5$563.9 million. We expect to continue to incur significant expenses and increasing operating losses for the foreseeable future. We expect that our expenses and capital expenditure requirements will increase substantially in connection with our ongoing activities, particularly if and as we:

WeBased believe thaton our current operating plan, existing cash and cash equivalents willare enableexpected usto fund operations into the second quarter of 2027, but are not expected to be sufficient to fund our currentobligations operatingfor planat intoleast twelve months after the secondissuance halfdate of 2027.these condensed consolidated financial statements. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. For additional information regarding our liquidity, see “Liquidity and Capital Resources” and “Risk Factors—Risks related to our financial position and need for additional capital.”

Three months ended MarchJune 31,30, 2026 and 2025

The following table summarizes our results of operations for the three months ended MarchJune 31,30, 2026 and 2025 (in thousands):

Revenue for the firstsecond quarter of 2026 was $1.0$1.1 million, compared to $2.2$3.1 million for the firstsecond quarter of 2025. The decrease was primarily due to the timing of research activities performed pursuant to our collaboration agreement with Amgen which commenced in May 2023.

The following table summarizes our research and development expenses for the three months ended MarchJune 31,30, 2026 and 2025 (in thousands):

Research and development expenses decreased $7.9$9.2 million and wasmillion, primarily attributable to a $5.2$6.8 million decrease in laboratory supplies, research materials and studies drivendue byto the timing in the purchase of supplies and consumables.consumables and decreased spend on contracted services. There was also a $1.0$2.1 million decrease in facility-related expenses related to the timing of tenant improvements at the 830 Winter Street expansion space. Clinical expenses decreased by $0.8 million and personnel expenses decreasedwhich was driven by $0.5 million in connection with our strategic decision in November 2025 to prioritize the clinical development of our heme program, upon which we paused enrollment in the solid tumor Phase 1 trial and reduced our headcount. Research and development expenses included non-cash stock compensation expense of $1.2 million and $1.7 million for the firstsecond quarter of 2026 and 2025, respectively.

The following table summarizes our general and administrative expenses for the three months ended MarchJune 31,30, 2026 and 2025 (in thousands):

General and administrative expenses decreased by $0.4$1.0 million and wasmillion, primarily attributable to a $0.3$0.7 million decrease in legal and professional fees, offset by a $0.5 million increase in personnel expenses. General and administrative expenses included non-cash stock compensation expense of $1.2 million and $1.7$1.6 million for the firstsecond quarter of 2026 and 2025, respectively.

Other income has decreased $1.7$1.6 million in the three months ended MarchJune 31,30, 2026 compared to the same period in 2025 primarily due to a decrease in interest income attributable to lower cash balances available for investment.

Pursuant to the K2HV Loan Agreement dated September 9, 2022, K2HV extended an initial convertible term loan of $30.0 million to the Company. On November 20, 2024, K2HV converted $15.0 million outstanding principal under the loan in exchange for 3,134,796 shares of our Voting Common Stock. On December 20, 2024, we entered into the SVB Loan Agreement, terminated the K2HV Loan Agreement and repaid all remaining outstanding loan obligations to K2HV. The SVB Loan Agreement provides for term loans up to an aggregate principal amount of $52.5 million, of which $32.5 million was provided on the closing date. WeThe haveterm loans would mature on September 1, 2029, and would be subject to monthly interest only payments until September 30, 2027, provided the optionCompany toachieved drawboth a secondcertain tranchefinancial and a certain clinical milestone by June 30, 2026, upon which the term loans would amortize with monthly installments of $20.0principal millionand atinterest beginning October 1, 2027 until maturity on September 1, 2029. No additional term loans were drawn and the lender'savailability soleof discretionsuch additional terms loans expired on or prior to June 30, 2026. As of June 30, 2026, the $32.5 million term loan remained outstanding under the SVB Loan Agreement. The Company did not achieve the specified financial milestone by June 30, 2026, and therefore, as provided in the SVB Loan Agreement, the interest-only period for such term loan will end on September 30, 2026, upon which monthly payments of principal and interest will be made thereafter until maturity on September 1, 2028. See “Notes to Condensed Consolidated Financial Statements” and “Item 1A. Risk factors—The terms of our loan agreement place restrictions on our operating and financial flexibility. If we raise additional capital through debt financing, the terms of any new debt could further restrict our operating and financial flexibility” for additional details regarding the SVB Loan Agreement.

We believe that our existing cash and cash equivalents will enable us to fund our current operating plan into the second halfquarter of 2027. We have based this estimate on assumptions that may prove to be wrong, and we could utilize our available capital resources sooner than we expect.

During the threesix months ended MarchJune 31,30, 2025,2026, net cash used in operating activities of $37.6$51.8 million was primarily driven by our net loss of $34.1$59.0 million, partially offset by non-cash charges of $2.9$6.6 million related to depreciation expense, accretion of marketable securities, stock-based compensation, loss on disposal, and non-cash interest expense related to note payable. During the threesix months ended MarchJune 31,30, 2025,2026, changes in working capital changescontributed resulted$0.7 in a usemillion of $6.4 million.cash. The change in working capital was primarily driven by revenue recognition related to the Amgen Agreement and changes in accrued expenses related to research and development activities.

During the threesix months ended MarchJune 31,30, 2026, net cash used in investing activities was $0.1$0.5 million, primarily related to the purchases of property and equipment.

During the threesix months ended MarchJune 31,30, 2025, net cash usedprovided inby investing activities was $13.5$62.0 million, primarily related to the purchases and maturities of marketable securities, and the purchases of property and equipment.

During the threesix months ended MarchJune 31,30, 2025,2026, net cash usedprovided inby financing activities was $0.5$0.1 million, consistingprimarily related to proceeds from the issuance of cashcommon paidstock forunder debtthe issuanceemployee andstock financingpurchase costs previously accrued.plan.