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

•We are substantially dependent on the success of our most advanced product candidate, NGN-401, and our ongoing and anticipated clinical trialstrial of NGN-401 may not be successful.

•We may be required to allocate resources to fulfilling the requirements of the ContingentCVR ValueAgreement, dated December 18, 2023, by and between us and the Rights Agent (the “CVR Agreement”) entered into in connection with the Reverse Merger (as defined below) related to certain legacy lease obligations which may take away from our core programs and create a distraction for our management and employees.

•Future sales of a substantial number of shares byof existingour stockholdersstock could cause our stock price to decline.

We are a clinical-stage biotechnology company with limited operating history. Since our inception in 2018, we have incurred significant operating losses and have used substantially all of our resources to conduct research and development activities, preclinical studies andstudies, Phase 1/2 clinical trials of our most advanced product candidates,candidates as well as a Phase 3 pivotal trial for NGN-401, establish in-house manufacturing capabilities, including analytical and process development operations to support ongoing manufacturing operations, manufacture product candidates, conduct business planning, develop and maintain our intellectual property portfolio, hire personnel, raise capital, and provide general and administrative support for these activities. We have limited experience as a company in initiating, conducting or completing clinical trials. In part because of this lack of experience, we cannot be certain that our current and planned clinical trials will begin on time, meet our anticipated timelines for enrollment and data analysis, or be completed on time, if at all. In addition, while we arehave conductingcompleted aenrollment in the Phase 1/2 clinical trial of NGN-401 in patients with Rett syndromesyndrome, initiated dosing in our EmboldenTM registrational trial for NGN-401 and have completed enrollment in a Phase 1/2 clinical trial of NGN-101 in patients with CLN5 Batten disease, we have not yet demonstrated our ability to successfully complete clinical trials (including Phase 3 or other pivotal clinical trials), obtain regulatory or marketing approvals, manufacture a commercial-scale product or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization. Additionally, we expect our financial condition and operating results to continue to fluctuate significantly from period to period due to a variety of factors, many of which are beyond our control. Consequently, any predictions made about our future success or viability may not be as accurate as they could be if we had a longer operating history.

In addition, as our business grows, we may encounter unforeseen expenses, restrictions, difficulties, complications, delays and other known and unknown factors. We will need to transition at some point from a company with ana limited focus on early research and development focusand small clinical trials to a company capablethat ofcan supportingalso larger pivotal clinical trials and eventuallysupport commercial activities, including the manufacture of commercial scale product. We may not be successful in such a transition.

Developing biotechnology products is a long, time-consuming, expensive and uncertain process that takes years to complete. Since our inception, we have funded our operations primarily through private financings and have incurred significant recurring losses, including a cumulative net loss from inception through December 31, 20242025 of $262.3$352.6 million. We expect our expenses to increase in connection with our ongoing activities, particularly aswith we continuerespect to conductour aEmbolden Phase 1/2registrational clinical trial of NGN-401 in patients with Rett syndrome, with the expectation that we will also initiate additional clinical trials in the future, and continue to research, develop and conduct preclinical studies of our other potential product candidates. We also anticipate that we may have near term expenses related to NGN-101 as we continue to evaluate options for the program following the denial by the FDA of ana Regenerative Medicine Advanced Therapy (“RMAT”) designation, which precludes our ability to use a streamlined registrational pathway necessary for further investment in the program.

We have incurred and expect to continue to incur additional costs associated with operating as a public company, and we do not anticipate achieving any significant revenue in the near term given the development stage of our product candidates. Accordingly, we will require substantial additional funding to continue our operations. Based on our current operating plan, we believe that our existing cash, cash equivalents and short-term investments should be sufficient to fund our operations intothrough the secondfirst halfquarter of 2027.2028. This estimate is based on assumptions that may prove to be materially wrong, and we could deplete our available capital resources sooner than we currently expect. Our future capital requirements will depend on many factors, including:

•the timing and progress of preclinical and clinical development activities, including any impact to our NGN-401 clinical trial activities relating to our participation in the FDA’s Support for clinical Trials Advancing Rare disease Therapeutics (“START”) program and the RegenerativeRMAT Medicineand AdvancedBreakthrough Therapy (“RMAT”)designations programfor NGN-401;

We do not have any committed external sources of funds,funds. We have filed an S-3 Registration Statement for the sale of up to $300.0 million in any combination of our common stock, preferred stock, debt securities, warrants or units, and may conduct one or more sales of securities pursuant to such registration statement from time to time. We have also entered into an at the market (“ATM”) Sales Agreement (the “Sales Agreement”) with Leerink Partners LLC (“Leerink”), pursuant to which, as of December 31, 2025, we have sold $31.0 million in shares of common stock, resulting in proceeds of $30.1 million after deducting sales commissions and other offering expenses. We may in the future, from time to time, offer and sell through Leerink up to an additional $119.0 million of the common stock registered under the shelf registration statement, pursuant to one or more “at the market” offerings. However, sales of our common stock under the Sales Agreement with Leerink are subject to business, economic or competitive uncertainties and contingencies, and adequate additional financing may not be available to us on acceptable terms, or at all. We may be required to or choose to seek additional funds sooner than planned through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources. Such financingfinancings may dilute our stockholders or the failure to obtain such financing may restrict our operating activities. Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our business. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted, and the terms may include liquidation or other preferences and anti-dilution protections that adversely affect your rights as a stockholder. Debt financing may result in imposition of debt covenants, increased fixed payment obligations or other restrictions that may affect our business. If we raise additional funds through upfront payments or milestone payments pursuant to future collaborations with third parties, we may have to relinquish valuable rights to product development programs, or grant licenses on terms that are not favorable to us. Additional capital may not be available in sufficient amounts or on reasonable terms, if at all. Our ability to raise additional capital may be adversely impacted by global macroeconomic conditions, including volatility in interest rates, escalating trade tensions and restrictions, tariffs, geopolitical instability, changes in government regulations and significant volatility in the credit and financial markets in the United States and worldwide, particularly in the biotechnology and biopharmaceutical industries, over which we may have no or little control. Our failure to raise capital as and when needed or on acceptable terms would have a negative impact on our financial condition and our ability to pursue our business strategy, and we may have to delay, reduce the scope of, suspend or eliminate clinical trials, product development programs or future commercialization efforts.

The development and commercialization of biological products is highly competitive. If approved, NGN-401 or any other product candidates we may develop will face significant competition and our failure to effectively compete may prevent us from achieving significant market penetration. We compete with a variety of multinational biopharmaceutical companies, specialized biotechnology companies and emerging biotechnology companies, as well as academic institutions, governmental agencies, and public and private research institutions, among others. Many of the companies with which we are currently competing or will compete against in the future have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, and marketing approved products than we do. Mergers and acquisitions in the pharmaceutical and biotechnology industry may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. New and emerging technologies for treatment of genetic diseases may create additional competitive pressures in our industry. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites and patient registration for clinical trials, as well as in acquiring technologies complementary to, or necessary for, NGN-401 and any other product candidates we may develop.

As described in “Business—Competition” in ourthis Annual Report on Form 10-K,Report, our competitors have developed, are developing or may develop programs or clinical stage products competitive with NGN-401 or our other earlier stage product candidates. Competitive therapeutic treatments include those that have already been approved and accepted by the medical community for Rett syndrome and any new treatments for Rett syndrome. Our success will depend partially on our ability to develop and commercialize products that have a competitive safety, efficacy or potency, dosing and/or presentation profile. Our commercial opportunity and success will be reduced or eliminated if competing products are safer, more effective or potent, have a more attractive or less invasive dosing profile or presentation or are less expensive than any products we may develop, or if competitors develop competing products that enter the market more quickly than we are able to, if we are able to at all, and are able to gain market acceptance.

NGN-401 is in clinical development and our preclinical programs are in early stages of development and may fail in development or suffer delays that materially and adversely affect their commercial viability. If we or our current or future collaborators are unable to complete development of, or commercialize, our product candidates, or experience significant delays in doing so, our business will be materially harmed.

We have no products on the market and while we have completed enrollment in our Phase 1/2 clinical trial of NGN-401 and initiated dosing in our Embolden registrational trial, NGN-401 is still in the early stages of clinical development.development stage. In addition, we announcedhave disclosed that unless we are able to find an alternative pathway for advancement, we will need to discontinue our NGN-101 program following the denial of RMAT designation for NGN-101 by the FDA, which would preclude a streamlined path to regulatory approval.

Our other programs are in early stages of preclinical development.development, and we expect to expend the majority of our resources on our Rett program for the near future, which may delay the development plans for our pipeline. As a result, we expect it will be manyseveral years before we commercialize our product candidates and ultimately may not be successful in commercializing any of our product candidates. Our ability to achieve and sustain profitability depends on obtaining regulatory approvals for, and successfully commercializing, our lead product candidate NGN-401 or other product candidates, either alone or with third parties, and we cannot guarantee that we will ever obtain regulatory approval for any product candidates we may develop.

InFollowing denial by the FDA of our RMAT application for NGN-101 for CLN5 Batten disease in November 2024, we announceddisclosed that we do not expect to move forward with the NGN-101 gene therapythat program for CLN5 Batten disease at this time. Given the rarity of the disease, continued investment in the program was predicated on alignment on a streamlined registrational pathway with the FDA. To support a streamlined pathway, we submitted an RMAT application to the FDA. Despite our belief that we met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT application was denied. Similar challenges may prevent our success with or increase the cost of other current, planned or future clinical trials. We or our collaborators may experience delays in initiating or completing clinical trials, and also may experience unforeseen events during, or as a result of, any current or future clinical trials that could delay or prevent our ability to receive marketing approval or commercialize NGN-401 or any other product candidates, including:

•clinical trials of any product candidates may fail to show safety orsafety, efficacy or potency, or may produce negative or inconclusive results, and we may decide, or regulators may require us, to conduct additional preclinical studies or clinical trials or we may decide to abandon product development programs;

If safety concerns develop with respect to our product candidates or clinical trial designs, we may be delayed in our development plans as we may need to pause our enrollment in a clinical trial, revise our trial designs, investigate potential safety developments, or take other measures that may increase the amount of time and resources required to bring our product candidates forward. For example, onin November 11, 2024, we were advised offollowing a severe adverse event (“SAE”) experiencedthat byresulted in a participantfatality in the 3E15 vg dose (high dose cohort) of our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome.syndrome, Thewe participant subsequently died following complications from a rare and life-threatening hyperinflammatory syndrome associated with systemic exposureelected to highinitially doses of AAV. The FDA completed a review of the safety data for NGN-401 and allowed us to continue with the Phase 1/2 trial using the 1E15 vg dose (low-dose cohort). We pausedpause further use of the 3E15 vg dose (high-doseand cohorts) upon initial notification of the SAE andsubsequently made the determination to remove that dose leveland fromalso thepaused enrollment until such time as we could update our trial protocol asto remove the 3E15vg dose and add additional safety monitoring protocols, which we dosubsequently not plan to enroll any further participants at the 3E15 vg dose level.did.

In November 2024, a participant who had been recently dosed inat the 3E15 vg (high dose) cohort of NGN-401 in our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome experienced an SAE consistent with known risks of AAV gene therapy and ultimately died from this complication. While this reaction was very rare, we cannot ensure that other SAEs related to the use of AAV9 will not occur, or that we will not experience delays or other negative impacts to our clinical trial related to this or other AAV-related SAEs. We also cannot be certain that we will be able to avoid triggering toxicities in our future preclinical studies or clinical trials or that our chosen routes of administration to deliver such therapies will not cause unforeseen side effects or other challenges. Although AAV9 has been shown to facilitate biodistribution and cell transduction to the central nervous system (“CNS”), the potentially limited levels of AAV9 transduction of cells in the CNS and certain retinal cells may also limit the potential efficacy or potency of any of our product candidates, including NGN-401.

Our primary product candidates, including NGN-401 for the treatment of Rett syndrome, are AAV-based gene therapies. AAV-based gene therapies in development or approved for use carry a risk of certain adverse side effects, known and unknown, including the potential for inflammatory events such as heightened innate or adaptive immune reactions in response to the presence of the AAV vector, including the development of a T-cell and/or B-cell immune response, complement system activation, thrombotic microangiopathy, thrombocytopenia, toxicity due to damage of the dorsal root ganglia, loss of nerve conductivity with or without the diminishment or loss of reflexes and sensory symptoms, increased liver enzymes and liver toxicity, organ damage to kidneys or the heart, vector integration that may result in cancerous cell development, or in rare cases, death. In addition, some participants in our AAV-based gene therapy clinical trials may have pre-existing conditions, such as diminished lean muscle mass, impaired function of biological systems or vital organs, or recent viral infections, or complications relating to their genetic makeup, and, as such, those participants may present a different risk profile and may have an increased potential for serious adverse events such as a heightened immune response, the re-activation of a viral infection due to immunosuppression measures that are taken in conjunction with administration of AAV-based gene therapy, or a diminished capacity to withstand treatment-related side effects that might be mild if they were to present in another participant. Because of the novel nature of gene therapy in general and specifically AAV-based gene therapy, not all side effects may have been discovered, and we may not be able to identify all of the increased risk factors for our participants, and additional unexpected serious adverse events may occur as a result. In addition, due to components of our product candidates used to carry the genetic materials, it is possible that some participants could develop delayed side effects from treatment. There can also be significant variability in how patients respond to gene therapy, especially in a mosaic disease presentation like Rett syndrome in females where some of the cells carry a correct copy of the DNA sequence for the impacted gene while other cells have a mutated variant. As a result, some patients may not respond as well to gene therapy as others.

AWe keyhave partinvested in early stage research and development with the goal of our business strategy is to identifyidentifying and developdeveloping additional product candidates.candidates Asas such,well as investments in research into new technologies to potentially augment our pipeline. Our future success dependsmay depend in part on the successful development of novel therapeutic approaches, including bynew utilizingtherapies that may be able to use our EXACT technology or other transgene regulation technology. OurHowever, while our preclinical research and clinical trials may initially show promise in identifying potential product candidates, yetthey may ultimately fail to yield product candidates for a number of reasons. For example, although EXACT is designed to deliver therapeutic levels of transgene while avoiding overexpression toxicity and off-target effects, there can be no assurance that any EXACT transgene regulation will result in product candidates that are shown in clinical trials to be safe, pure, and effective or potent.

As a result, it is difficult for us to predict the time and cost of product candidate development, and we cannot predict whether the application of our approach to gene therapy will result in the identification, development, and regulatory approval of any product candidates, or that other gene therapy programs will not be considered better or more attractive. There can be no assurance that any development problems we experience in the future related to our current gene therapy approaches or product candidates or any of our research programs will not cause significant delays or unanticipated costs, or that such development problems can be solved. Research programs to identify new product candidates require substantial technical, financial, and human resources. If we are unable to identify suitable gene therapy product candidates for preclinical and clinical development,development in a cost effective manner, we may not be able to successfully implement this portion of our business strategy, and may have to delay, reduce the scope of, suspend or eliminate one or more of our current or future product candidates, clinical trials or future commercialization efforts, which would negatively impact our financial condition.

Trials may be subject to delays as a result of patient enrollment taking longer than anticipated or patient withdrawal. We may not be able to initiate or continue clinical trials for our product candidates if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA, the Medicines and Healthcare products Regulatory Agency (“MHRA”) in the United Kingdom, the Therapeutic Goods Association (“TGA”) in Australia, the European Medicines Agency (“EMA”) or other foreign regulatory authorities. We cannot predict how successful we will be at enrolling subjects in future clinical trials. Subject enrollment is affected by other factors including:

The discovery and development of therapeutics for patients with neurological diseases is an emerging field, and the scientific discoveries that form the basis for our efforts to discover and develop product candidates are relatively new. The scientific evidence to support the feasibility of developing product candidates based on these discoveries is both preliminary and limited. Although we believe, based on our preclinical work, that our programs have the potential to be disease-modifying therapies, clinical results may not confirm this hypothesis or may only confirm it for certain alterations or certain indications. The patient populations for our product candidates are limited to those with specific neurological diseases. We cannot be certain that the patient populations for each specific disease will be large enough to allow us to successfully obtain approval and commercialize our product candidates and achieve profitability. Further, our Phase 1/2 clinical trial of NGN-401 will involveinvolves a small patient population. Because of the small sample sizes, the expansion of our clinical trial to an adolescent/adult cohort and the heterogeneity of the disease state, the results of this trial may not be indicative of results of future clinical trials. In particular, while we have expanded the clinical trial of NGN-401 to include adolescent and adult patients in both our Phase 1/2 trial and our Embolden registrational trial, our interim data releases to date have focused solely on pediatric participants in those trials, and we cannot be sure that the results that we have reported in our pediatric population of that trial will be representative of our adolescent or adult participants.

Furthermore, failure can occur at any time during the preclinical study or clinical trial process, and the outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials, especially as our initial clinical trials do not contain a control arm. In addition, we have designed our initial clinical trials with relatively small cohorts before expanding in size and dosing in subsequent cohorts. If safety issues arise in an early cohort, we may be delayed or prevented from dose escalating or subsequently expanding into larger trial cohorts. For example, onin November 11, 2024, we were advised offollowing an SAE experienced by a recently dosed participant inat the 3E15 vg (high dose cohort) ofin our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome.syndrome Thethat participantresulted subsequently died following complications fromin a rare and life threatening hyperinflammatory syndrome associated with systemic exposure to high doses of AAV. The FDA completed a review of the safety data for NGN-401 and allowed us to proceed with the Phase 1/2 trial using the 1E15 vg dose (low-dose cohort), althoughfatality, we decidedelected to revise our trial protocol before resuming dosing,dosing and have removedremove the 3E15 vg dose level from the trial protocol aswith weno do not planplans to enroll any further participants at the that dose level.dose.

We cannot be sure that the FDA or comparable foreign regulatory authorities will agree with our clinical development plan. We arehave conductingcompleted aenrollment in our Phase 1/2 clinical trial of NGN-401 in patients with Rett syndrome.syndrome Ifand have commenced dosing in our Embolden registrational trial for NGN-401. However, if the FDA or any comparable regulatory authorities require us to conduct additional trials or enroll additional patients, our development timelines may be delayed, or we may not be able to pursue further development due to such delays. For example, in November 2024, we announced that thewe Company doesdo not expect to move forward with the NGN-101 for CLN5 Batten disease gene therapy program at this time. Given the rarity of the disease, continued investment in the program was predicated on alignment on a streamlined registrational pathway with the FDA. To support a streamlined pathway, we submitted an RMAT application to the FDA. Despite our belief that we met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT application was denied. We cannot be sure that submission of an IND application, clinical trial application (“CTA”) or similar application will result in the FDA or comparable foreign regulatory authorities, as applicable, allowing clinical trials to begin in a timely manner, if at all. Moreover, even if these trials begin, issues may arise that could cause regulatory authorities to require us to suspend or terminate such clinical trials. Events that may prevent successful or timely initiation or completion of clinical trials include: inability to generate sufficient preclinical, toxicology or other in vivo or in vitro data to support the initiation or continuation of clinical trials; delays in reaching a consensus with regulatory authorities on study design or implementation of the clinical trials; delays or failure in obtaining regulatory authorization to commence a trial; delays in reaching agreement on acceptable terms with prospective CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and clinical trial sites; delays in identifying, recruiting and training suitable clinical investigators; delays in obtaining required IRB approval at each clinical trial site; difficulties in patient enrollment in our clinical trials for a variety of reasons; delays related to safety concerns; delays in manufacturing, testing, releasing, validating or importing/exporting sufficient stable quantities of our product candidates for use in clinical trials or the inability to do any of the foregoing; failure by our CROs, other third parties or us to adhere to clinical trial protocols; failure to perform in accordance with the FDA’s or any other regulatory authority’s good clinical practices (“GCPs”) or applicable regulatory guidelines in other countries; changes to the clinical trial protocols; clinical sites deviating from trial protocol or dropping out of a trial; changes in regulatory requirements and guidance that require amending or submitting new clinical protocols; selection of clinical endpoints that require prolonged periods of observation or analyses of resulting data; transfer of manufacturing processes to larger-scale facilities operated by a CDMO and delays or failure by our CDMOs or us to make any necessary changes to such manufacturing process and demonstrate comparability to materials used in earlier clinical phases; and third parties being unwilling or unable to satisfy their contractual obligations to us.

In addition, even if we are able to successfully complete the clinical trial for NGN-401, we cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. This is particularly true for clinical trials in very rare diseases, such as with our PhaseEmbolden 1/2 clinicalregistrational trial of NGN-401 for the treatment of Rett syndrome, where the very small patient population makes it difficult to conduct two traditional, adequate and well-controlled studies. In such cases, the FDA or comparable foreign regulatory authorities are often required or permitted to exercise flexibility in approving therapies for such diseases, but obtaining flexibility is uncertain and may never occur. Moreover, results acceptable to support approval in one jurisdiction may be deemed inadequate by another regulatory authority to support regulatory approval in the other jurisdiction. To the extent that the results of the trials are not satisfactory to the FDA or applicable regulatory authorities for support of a marketing application, we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates.

From time to time, we may publicly disclose preliminary, interim or topline data from our preclinical studies and clinical trials, which are based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data. We also make assumptions, estimations, calculations and conclusions as part of our analyses of these data without the opportunity to fully and carefully evaluate complete data. Preliminary, interim or topline results also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data previously disclosed. These preliminary, interim or topline data 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 or as patients from our clinical trials continue other treatments. For example, in June 2024, we announced initial safety data related to the dosing of our first four participants inat the 1E15 vg dose cohort ofin our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome which suggested a favorable safety profile for the 1E15 vg dose. In November 2024, an SAE was reported in a participant who received the 3E15 vg dose (high-dose),dose, which caused us to revise our assumptions regarding the safety profile of the 3E15 vg dose (high-dose).dose. Because of this potential for change, preliminary, interim and topline data should be viewed with caution until final data are available. Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular product candidate, the approvability or commercialization of a particular product candidate and our company in general. In addition, the information we choose to publicly disclose regarding a particular preclinical study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure. If the preliminary, interim or topline data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, NGN-401 or any other product candidate may be harmed, which could harm our business, operating results, prospects or financial condition. In addition, differences between preliminary, interim or topline data and final data could significantly harm our business prospects and may cause the trading price of our common stock to fluctuate significantly.

Results of our clinical trials could reveal a high and unacceptable severity and prevalence of side effects, adverse events or unexpected characteristics. We believe NGN-401 has been generally well-tolerated at the 1E15 vg dose; however, we have not yet completed this clinical trial and the benefit-risk assessments of our product candidates remains ongoing. In November 2024, a participant who had recently received the 3E15 vg dose of NGN-401 experienced an SAE consistent with the known risks of AAV gene therapy and subsequently died following complications from a rare and life-threatening hyperinflammatory syndrome associated with systemic exposure to high doses of AAV. Participants at the 1E15 vg dose level have also experienced adverse events, and may experience adverse events in the future. If additional SAEs or other adverse events or other side effects are observed in any of our current or future clinical trials, we may have difficulty recruiting patients to such trials, patients may drop out of our trials, patients may be harmed, or we may be required to delay enrollment or abandon one or more cohorts of a trial or delay or abandon the trials or our development efforts of one or more product candidates altogether, including NGN-401. We, the FDA, MHRA, or other applicable regulatory authorities, or an IRB, may require suspension of any clinical trials of NGN-401 or any other product candidates at any time for various reasons, including a finding that subjects or patients in such trials are being exposed to unacceptable health risks or adverse side effects. Some potential products developed in the biotechnology industry that initially showed therapeutic promise in early-stage trials have later been found to cause side effects that prevented their further development. Even if the side effects do not preclude a product candidate from obtaining or maintaining marketing approval, undesirable side effects may inhibit market acceptance of an approved product due to its tolerability versus other therapies. In addition, as gene replacement has a potentially life-long activity, with no ability to withdraw the product as with other treatment modalities, this profile could prolong the duration of undesirable side effects, which could also inhibit market acceptance. Treatment-emergent adverse events could also affect patient recruitment or the ability of enrolled subjects to complete our clinical trials or could result in potential product liability claims. Potential side effects associated with NGN-401 or any other product candidates may not be appropriately recognized or managed by the treating medical staff, as toxicities resulting from NGN-401 or any other product candidates may not be normally encountered in the general patient population and by medical personnel. Any of these occurrences could harm our business, financial condition, results of operations and prospects significantly.

In addition, even if we successfully advance NGN-401 or any other product candidates through clinical trials, such trials will only include a limited number of patients and limited duration of follow up to such product candidates. As a result, we cannot be assured that adverse effects of NGN-401 or any other product candidates will not be uncovered when a significantly larger number of patients are exposed to such product candidate after approval, or a significantly longer follow up post-dosing is obtained as part of regulators’ recommendations for long-term follow up of clinical study subjects treated with gene therapy. For example, product candidates tested in clinical-stage gene therapy trials by commercial stage companies have later been involved in well-publicized adverse events after approval and commercialization, including death, and/or have failed to demonstrate the expected efficacy. Lack of efficacy or the occurrence of serious adverse events, even if such adverse events are not ultimately attributable to the relevant product candidate, may result in increased government regulation, unfavorable public perception of gene therapies, potential regulatory delays in the testing or approval of our product candidates, stricter labeling requirements for those product candidates that are approved and a decrease in demand for any such product candidate. Further, any clinical trials may not be sufficient to determine the effect and safety consequences of using our product candidates over a multi-year period. For example, another company pursuing gene therapy in a clinical trial for a different rare disease recently reported the discovery of cancer believed to have been caused by vector integration several years after an AAV-based gene therapy treatment was received by that patient, although causality has yet to be fully established. While we believe such subsequent adverse events to be rare, because gene therapy is relatively new, there may be other potential risks of gene therapy that may emerge in the years following treatment of which we are not yet aware. Safety issues in other AAV-based gene therapy programs could result in increased regulatory scrutiny, new guidance, clinical holds on our trials, protocol amendments, or delays affecting our programs even if our trials have not experienced similar events.

We have expended substantial efforts and costs testing our EXACT technology in preclinical studies of NGN-401, including completing toxicology studies prior to the FDA providing clearance of the IND for NGN-401.NGN-401 and have not seen any adverse effects that we believe are attributable to EXACT in our Phase 1/2 trial of NGN-401 as of our most recent data cut off date of October 30, 2025. However, we cannot guarantee that significant adverse effects will not be seen in the future in clinical trials for NGN-401, which could result in clinical holds, delays, suspension or withdrawal of our IND. If any of the foregoing events occur or if NGN-401, NGN-101 or any other product candidates prove to be unsafe, our entire pipeline could be affected, which would have a material adverse effect on our business, financial condition, results of operations and prospects.

Because we have limited financial and managerial resources, we intend to focus our research and development efforts on certain selected product candidates. For example, toTo date we have allocated significant resources to our most advanced product candidates, NGN-401 and NGN-101. As a result, we may forgo or delay pursuit of opportunities with other potential candidates that may later prove to have greater commercial potential. For example, in November 2024, we announced that thewe Company doesdo not expect to move forward with the NGN-101 for CLN5 Batten disease gene therapy program at this time. Given the rarity of the disease, continued investment in the program was predicated on a streamlined registrational pathway with the FDA. To support a streamlined pathway, we submitted an RMAT application to the FDA. Despite our belief that we met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT designation was denied. Our resource allocation decisions may cause us to fail to capitalize on viable commercial products or profitable market opportunities. Our spending on current and future research and development programs for specific indications may not yield any commercially viable product candidates. If we do not accurately evaluate the commercial potential or target market for a particular product candidate, we may relinquish valuable rights to that candidate through collaboration, licensing or other royalty arrangements in cases in which it would have been more advantageous for us to retain sole development and commercialization rights to such candidate.

We are early in our development efforts and will need to successfully complete later-stage and pivotal clinical trials in order to obtain FDA or comparable foreign regulatory approval to market our product candidates. Carrying out clinical trials and the submission of a successful IND or CTA is a complicated process. Even though our product candidate NGN-401 for Rett syndrome has been accepted into the FDA’s START program and granted Breakthrough Therapy and RMAT program,designations, the combination of which is expected to allow access to frequent advice from FDA staff, intensive guidance on efficient drug development and eligibility for an Accelerated Approval pathway and Priority Review, our lack of experience with FDA submissions may still slow our progress towards FDA approval. We have completed enrollment in both our Phase 1/2 trial of NGN-101 for the treatment of CLN5 Batten disease and our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome and have commenced dosing in our Embolden registrational trial for NGN-401 in the United States; however, we have not yet completed a Phase 1/2 clinical trial and have limited experience as a company in preparing, submitting and prosecuting regulatory filings. BasedWe on the initial positive interim data from the 1E15 vg dose of NGN-401 in our Phase 1/2 clinical trial of NGN-401, we intendexpect to engage with the FDA and other comparable foreign regulators to determine the requirements to support initiation of a pivotal clinical trial.trial However,in foreign countries; however, those regulatory authorities may have different requirements for approval, including different requirements for clinical trial designs, and may recommend or require changes to the study design for NGN-401, including the number and size of registrational clinical trials required to be conducted in that program.program Into addition,be regulatoryconsidered for approval. Regulatory authorities could also require manufacturing changes or have us implement additional analytical processes prior to initiation of a future clinical trial. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to regulatory submission and approval of our product candidates or we may determine that the regulatory requirements for submission are too burdensome to support continued development of one or more of our product candidates, as we did with our NGN-101 product candidate for CLN5 Batten disease, which we do not plan to terminatemove forward with due to a lack of alignment with the FDA on a streamlined pathway to registration. Additionally, even if regulatory authorities agree with the design and implementation of the clinical trials set forth in a regulatory meeting, such regulatory authorities may change their requirements in the future. The FDA or comparable foreign regulatory authorities may require the analysis of data from trials assessing different doses of the product candidate alone or in combination with other therapies to justify the selected dose prior to the initiation of large trials in a specific indication. Any delays or failure to initiate clinical trials or obtain regulatory approvals for our trials may prevent us from completing our clinical trials or commercializing our products on a timely basis, if at all. We are subject to similar risks related to the review and authorization of our protocols and amendments by comparable foreign regulatory authorities.

Once the biological products are manufactured, the product must be analyzed utilizing assays and meet pre-determined specifications in order to be used in certain preclinical studies, in any clinical trial, and, if approval is obtained, for commercial distribution. This testing is performed in-house and at third-party contract manufacturers. Delays or other unexpected obstacles in developing analytical methods or in performing the tests and obtaining the results in-house or at a third-party contractor could result in unanticipated impact to our ability to supply material as needed for pre-clinical,preclinical, clinical, or commercial needs.

Delays in developing our manufacturing capabilities or failure to achieve operating efficiencies from such capabilities may require us to devote additional resources and management time to manufacturing operations for future product candidates and may delay our product development timelines.

We have a GMP manufacturing facility located in Houston, Texas that includes process, analytical and bioanalytical development labs with experienced teams. NGN-401 was manufactured at our Houston facility and clinical-grade product iswas availableused for dosing in the Phase 1/2 clinical trial of NGN-401 thatand is currentlybeing enrollingused patients.for However,dosing in the Embolden trial. While we willhave needadequate material for our NGN-401 clinical trial program, we expect to conduct additional NGN-401 manufacturing campaigns in the future to generate additionalsupply clinicalof supply,other asproduct well as supplycandidates for our preclinical studies for our discovery programs, and we may not be able to satisfy such supply through production at our own facility and may need to outsource some or all of our production work.

To date, we have manufactured NGN-401 in quantities and quality adequate for preclinical, toxicology and clinical studies. In order to conduct clinical trials for a product candidate and for commercialization of the resulting product if that product candidate is approved for sale, we will need to manufacture future product candidates in additional cGMP campaigns orwhich inmay also requires us to manufacture using larger batch sizes. We may not be able to successfully repeatmanufacture orsufficient increasequantity, theincluding any necessary increases in manufacturing capacitycapacity, for any of our future product candidates in a timely or cost-effective manner or at all. Significant changes or scale-up of manufacturing may require additional validation studies and/or analytical comparability studies, which are costly and which regulatory authorities must review and approve. In addition, quality issues may arise during those changes or scale-up activities. If we are unable to successfully manufacture any of our future product candidates in sufficient quality and quantity, the development of that product candidate and regulatory approval or commercial launch for any resulting products may be delayed or there may be a shortage in supply, which could significantly harm our business.

Further, under the MCA, the University of Edinburgh is primarily responsible for prosecuting and maintaining our licensed intellectual property, and it may fail to properly prosecute, maintain or defend such intellectual property. In such event, if we are unable to otherwise maintain or defend such intellectual property, we could face the potential invalidation of the intellectual property or be subjected to litigation or arbitration, any of which would be time-consuming and expensive. To enforce the licensed intellectual property rights under the MCA, we will need to coordinate with the University of Edinburgh, which could slow down or hamper our ability to enforce our licensed intellectual property rights. If this happens, we could face increased competition that could materially and adversely affect our business. For a further description of the MCA, see Part II, Item 7 of this Annual Report on Form 10-K titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations—License and Collaboration Agreements.”

We have engaged CROs or other third parties to conduct preclinical and IND enabling studies and our clinical trials, including our Phase 1/2 clinical trial and our Embolden registrational trial of NGN-401. We currently use CDMOs to provide certain research-grade materials and may in the future use CDMOs for future clinical trials for other product candidates.

We expect to continue to rely on third parties, including CROs, medical institutions and clinical investigators, to conduct those clinical trials.trials, and to rely on CDMOs for some of our research activities and potentially for clinical trials in the future. Any of these third parties may terminate their engagements with us, some in the event of an uncured material breach and some at any time for convenience. If any of our relationships with these third parties terminate, we may not be able to timely enter into arrangements with alternative third parties or do so on commercially reasonable terms, if at all. SwitchingFor example, switching or adding CROs involves substantial cost and requires management time and focus. In addition, there is a natural transition period when a new CRO commences work. As a result, delays occur, which can materially impact our ability to meet our desired clinical development timelines. Though we intend to carefully manage our relationships with CROs,CROs and with all of our other third party providers, there can be no assurance that we will not encounter challenges or delays in the future or that these delays or challenges will not have a material adverse impact on our business and financial condition.

Further, while our reliance on these third parties for research and development activities will reduce our control over these activities, we will not be relieved of our responsibilities for ensuring that each of our studies and trials is conducted in accordance with the applicable protocol, legal, regulatory and scientific standards. For example, we will remain responsible for ensuring that each of our clinical trials is conducted in accordance with the general investigational plan and protocols for the trial. Moreover, the FDA requires us to comply with GCPs for conducting, recording and reporting the results of clinical trials to assure that data and reported results are credible and accurate and that the rights, integrity and confidentiality of trial participants are protected. We also are required to register ongoing clinical trials and post the results of completed clinical trials on a government-sponsored database, ClinicalTrials.gov, within specified timeframes. Failure to do so can result in fines, adverse publicity and civil and criminal sanctions. If we or any of our CROs or other third parties, including trial sites, fail to comply with applicable GCPs, the clinical data generated in our clinical trials may be deemed unreliable and the FDA, MHRA, EMA or comparable foreign regulatory authorities may require us to perform additional clinical trials before approving our marketing applications. We cannot assure you that upon inspection by a given regulatory authority, such regulatory authority will determine that any of our clinical trials complies with GCP regulations. In addition, our clinical trials must be conducted with productproducts produced under cGMP conditions. Our failure to comply with these regulationsregulations, or the failure of any CDMO that we may use in the future for clinical trials to so comply, may require us to repeat clinical trials, which would delay the regulatory approval process.

Our ability to compete in the highly competitive biotechnology and pharmaceutical industries depends upon our ability to attract and retain highly qualified managerial, scientific and medical personnel. We are highly dependent on our managerial, scientific and medical personnel, including our Founder and Chief Executive Officer, President and Chief Financial Officer, andChief Medical Officer, Chief Scientific Officer,Officer and Senior Vice President of Technical Operations, as well as other key members of our leadership team. Our executive officers and other key personnel may terminate their employment with us at any time. We do not maintain “key person” insurance for any of our executives or other employees. The loss of the services of our executive officers or other key employees could impede the achievement of our research, development and commercialization objectives and seriously harm our ability to successfully implement our business strategy. Furthermore, replacing executive officers and key personnel may be difficult and may take an extended period of time. Failure to attracting and retaining qualified personnel could materially and adversely affect our business, financial condition and results of operations. We could in the future have difficulty attracting and retaining experienced personnel and may be required to expend significant financial resources on our employee recruitment and retention efforts.

Our future growth may depend, in part, on our ability to develop and commercialize NGN-401 or other product candidates in foreign markets for which we may rely on collaborations with third parties. We are not permitted to market or promote any product candidates before we receive regulatory approval from the applicable foreign regulatory authority, and may never receive such regulatory approval for any product candidates. To obtain separate regulatory approval in many other countries, we must comply with numerous and varying regulatory requirements of such countries regarding safety and efficacy and governing, among other things, clinical trials and commercial sales, pricing and distribution of NGN-401 or other product candidates, and we cannot predict success in these jurisdictions. If we fail to comply with the regulatory requirements in international markets or to receive applicable marketing approvals, our target market will be reduced and our ability to realize the full market potential of NGN-401 or other product candidates will be harmed and our business will be adversely affected. Moreover, even if we obtain approval of NGN-401 or other product candidates and ultimately commercialize such product candidates in foreign markets, we would be subject to the risks and uncertainties of operating in such foreign markets, including the burden of complying with complex and changing foreign regulatory, tax, accounting and legal requirements and reduced protection of intellectual property rights in some foreign countries.

Our systems, or those of any of our CROs, CDMOs, manufacturers, other contractors, third party service providers or consultants or potential future collaborators, may fail or suffer security or data privacy breaches or other unauthorized or improper access to, use of, or destruction of our proprietary or confidential data, employee data or personal data, which could result in additional costs, loss of revenue, significant liabilities, harm to our brand and material disruption of our operations.

Despite the implementation of security measures in an effort to protect systems that store our information, given the size and complexity of such systems and the increasing amounts of information maintained on our internal information technology systems and those of our third-party CROs, CDMOs, other contractors (including sites performing our clinical trials), third-party service providers and supply chain companies, consultants and other partners, these systems are potentially vulnerable to breakdown or other damage or interruption from service interruptions, system malfunction, natural disasters, terrorism, war, and telecommunication and electrical failures, as well as security breaches from inadvertent or intentional actions by our employees, contractors, consultants, business partners and/or other third parties, or from cyber-attacks by malicious third parties, which may compromise our system infrastructure or lead to the loss, destruction, alteration or dissemination of, or damage to, our data. From time to time, we are subject to business email compromise attack attempts. In August 2023, we discovered a business email compromise attack that resulted in the misappropriation of approximately $0.9 million. While we have implemented remedial measures in response to this incident and recovered $0.8 million of those losses through insurance claims, we cannot guarantee that such measures will prevent additional related, as well as unrelated incidents, or that we will be able to defend against or successfully remediate any such attacks that may occur in the future. If a material system failure, accident or security breach were to occur and cause interruptions in our operations or the operations of third-party collaborators, service providers, contractors and consultants, it could result in a material disruption of our development programs and significant reputational, financial, legal, regulatory, business or operational harm.

We, and third parties with whom we work, are or may become subject to numerous domestic and foreign laws, regulations, and standards relating to privacy, data protection, and data security, the scope of which are changing, subject to differing applications and interpretations, and may be inconsistent among countries, or conflict with other rules. InFor addition,example, therethe isBIOSECURE proposedAct, legislationenacted in theDecember U.S.2025, Congress that could restrict working with certain biotech providers who are deemed “companies of concern” which may impactrestricts the ability of certainfederal thirdagencies partiesand their contractors to work with whomdesignated we“biotechnology workcompanies of concern.” The implementation of this Act, including the forthcoming publication of a comprehensive list of restricted entities by the Office of Management and Budget, may require us to meetterminate theiror performancetransition obligations.existing relationships with certain third-party service providers, which could disrupt our data processing capabilities or clinical trial operations. We are or may become subject to the terms of contractual obligations related to privacy, data protection, and data security. Our obligations maycontinue alsoto change orand expand as our business grows.grows, particularly with the proliferation of state-level comprehensive privacy laws in the U.S. The actual or perceived failure by us or third parties related to us to comply with such laws, regulations and obligations could increase our compliance and operational costs, expose us to regulatory scrutiny, actions, fines and penalties, result in reputational harm, lead to a loss of customers, result in litigation and liability, subject us to injunctive restrictions on data processing, adversely impact our ability to appropriately manage third parties with whom we work and otherwise cause a material adverse effect on our business, financial condition, and results of operations. See “Business—Government Regulation—Data Privacy and Security” and “—Other Regulatory Matters” in our Annual Report on Form 10-K for a more detailed description of the laws that may affect our ability to operate.

We are subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Our operations may involve the use of hazardous and flammable materials, including chemicals and biological and radioactive materials. In addition, we may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair our research, development or commercialization efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties or other sanctions.

The rules dealing withgoverning U.S. federal, state and local income taxation are constantly under review and modification by persons involved in the legislative process and by the Internal Revenue Service (“IRS”) and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect us or our stockholders. We assess the potential impact of various tax reform proposals and modifications to existing tax treaties in all jurisdictions where we have operations and employees to determine the potential effect on our business and any assumptions we have made and make about our future taxable income. We cannot predict whether any specific proposals will be enacted, the terms of any such proposals or what effect, if any, such proposals would have on our business if they were to be enacted. For example, the United States recently enacted the Inflation Reduction Act of 2022, which implements, among other changes, a 1% excise tax on certain stock buybacks. In addition, beginning in 2022, the Tax Cuts and Jobs Act eliminated the option to deduct research and development expenditures and requires taxpayers to amortize them generally over five years. The U.S. Congress is considering legislation that would restore the current deductibility of research and development expenditures, however, there is no assurance that the provision will be repealed or otherwise modified. Such changes, among others, may adversely affect our effective tax rate, results of operation and general business condition.

Our intellectual property portfolio is at an early stage. As of December 31, 2024,2025, our licensed intellectual property only includes four issued patents, all of which are related to our NGN-101 program which we doare notno ownlonger oractively in-license any issued patents.pursuing. Our pending and future patent applications may not result in patents being issued. Any issued patents may not afford sufficient protection of our product candidates or their intended uses against competitors, nor can there be any assurance that the patents issued will not be infringed, designed around, invalidated by third parties, or effectively prevent others from commercializing competitive technologies, products or product candidates. Even if these patents are granted, they may be difficult to enforce. Further, any issued patents that may be licensed or owned covering our product candidates could be narrowed or found invalid or unenforceable if challenged in court or before administrative bodies in the United States or abroad, including the United States Patent and Trademark Office (“USPTO”). Further, if we encounter delays in any clinical trials or delays in obtaining regulatory approval, the period of time during which we could market product candidates under patent protection would be reduced. Thus, the patents that we may own or license may not afford any meaningful competitive advantage.

Despite recent scientific advances in genetics, most neurological diseases, particularly those with devastating consequences to patients, are left untreated. Conventional gene therapy is an attractive potential treatment approach for only a limited number of monogenic diseases due to the challenges caused by the complex biology of neurological diseases and by inherent variable transgene uptake and expression. We are a clinical-stage biotechnology company committed to overcoming these limitations and turning today’s complex devastating neurological diseases into treatable conditions. By harnessing our proprietary transgene regulation technology, EXACTTM (Expression Attenuation via Construct Tuning), weWe are building a robust and differentiated product portfolio of genetic medicines for rare neurological diseases with high unmet need not otherwise addressable by conventional gene therapy. Our EXACTOne approach leverageswe keyare scientifictaking breakthroughs,harnesses includingour geneproprietary transfertransgene regulation technology, EXACTTM (Expression Attenuation via Construct Tuning), that utilizes microRNA-based genetic circuits,circuits andthat adeno-associated virus (“AAV”) delivery, and isare designed to deliver therapeutic levels of transgene to key areas of the brain that underlie neurological disease pathology.

In November 2024,2025, we announced updated positive interim clinical data from the Phase 1/2 NGN-401 trial in participantsthe pediatric cohort (ages 4-10) receiving the 1E15 vg dose (n=48 for efficacy data; n=510 for safety datadata, including pediatric and adolescent/adult participants) from the Phase 1/2 clinical trial with a data cut-offcutoff date of October 17,30, 2024.2025.

InBased Decemberon 2024,research we updatedconducted ourin Phase 1/2 protocol to remove the 3E15 vg dose from the trial, and we are currently enrolling participants. Despite our research2025 related to hyperinflammatory syndromes and AAV gene therapy showing thattherapy, HLH has only been reported following doses of systemic AAV that are highergenerally thanin the 1E14 vg/kg range or higher. The 1E15 vg dose level,used in the Phase 1/2 trial and in the Embolden registrational trial translates into the E13 vg/kg range, and we are not aware of any case of HLH ever being reported at this dose. Out of an abundance of caution, we haveincorporated incorporatedenhanced monitoring into our protocolPhase additional1/2 monitoringand Embolden protocols for markers using the HLH diagnosticmarkers, criteria, such asincluding ferritin, and a treatment algorithm.algorithm Whenthat when administered early, this treatment algorithm has been used successfully to treat cases of HLH both in other AAV gene therapytherapies and other known causes of HLH.

In June 2024, we announced that NGN-401 was one of four sponsors selected by the Center for Biologics Evaluation and Research at the FDA to participate in the FDA’s Support for clinical Trials Advancing Rare disease Therapeutics (“START”) Pilot Program based on potential for clinical benefits and clinical development program readiness. As part of the START Program, we have opportunities for enhanced communications with the FDA, with the aim to further accelerate the pace of NGN-401’s development. These opportunities are designed to provide frequent advice and regular ad-hoc conversations to address product-specific development issues, including, but not limited to, clinical study design, choice of control group and fine-tuning the choice of patient population. In August 2024, we announced that NGN-401 also received Regenerative Medicine Advanced Therapy (“RMAT”) designation from the FDA. RMAT designation is granted for regenerative medicines intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition, and with preliminary clinical evidence that indicates that the drug has the potential to address unmet medical needs. Benefits of the RMAT designation program include all the benefits of Fast Track and Breakthrough Therapy designation programs, including early and frequent communications with FDA senior managers, intensive guidance on efficient drug development and eligibility for an Accelerated Approval pathway and Priority Review.

We believe that our EXACT platform has broad applicability in complex neurological diseases not otherwise easily addressable by conventional gene therapy. In addition to our Rett syndrome program,NGN‑401, we haveare multipleadvancing early‑stage discovery programs leveraging our EXACT platform for other potential indications. These programs are in the discovery stage.stage, and we have not yet selected a clinical development candidate.

In addition to NGN-401, we haveWe also been pursuingpursued a conventional gene therapy program in an ongoing Phase 1/2 clinical trial of NGN-101 for the treatment of CLN5 Batten disease. ThisWe patientcompleted populationenrollment hasin a significant unmet need and experiences extensive neurological and physical impairment leading to blindness, loss of motor function and early mortality. Our Phase 1/2 clinical trial of NGN-101 was the first trial to assess the treatment of both neurodegenerativeNGN-101, and ocular disease manifestations of Batten disease. Inin November 2024, we announced that we do not expect to move forward withadvance the NGN-101 CLN5 Batten disease gene therapy program at this time. Given the rarity of the disease, continued investment in the program was predicated on alignment with the FDA on a streamlined registrational pathway with the FDA.pathway. To support athis streamlined pathway,objective, we submitted an RMAT applicationapplication, to the FDA. Despite our belief that we met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT applicationwhich was denied. We are currently evaluating options for the program.

We were founded in 2018, and have devoted substantially all of our resources to conducting research and development activities (including with respect to the NGN-401 and NGN-101 programs) and undertaking preclinical studies, establishing our manufacturing facility, conducting clinical trials and the manufacturing of product used in our clinical trials and preclinical studies, business planning, developing and maintaining our intellectual property portfolio, hiring personnel, raising capital, and providing general and administrative support for these activities.

Since our inception, we have funded our operations primarily with outside capital (e.g., proceeds from the sale of preferred stock, common stock and commonpre-funded stockwarrants) and have raised aggregate net proceeds of approximately $521.9$552.1 million from these private placements.million. However, we have incurred significant recurring losses, including a net loss of $75.1$90.4 million and $36.3$75.1 million for the years ended December 31, 20242025 and 2023,2024, respectively. In addition, as of December 31, 2024,2025, we had an accumulated deficit of $262.3$352.6 million and cash, cash equivalents and short-term investments totaling $312.4$269.0 million. In order to continue our operations, we must achieve profitable operations and/or obtain additional equity or debt financing. Until we achieve profitability, management plans to fund our operations and capital expenditures with cash on hand and the sale and issuance of securities. There can be no assurance that we will be successful in raising additional capital or that such capital, if available, will be on terms that are acceptable to us. If we are unable to raise sufficient additional capital, we may be compelled to consider actions such as reducing the scope of our operations and planned capital expenditures or selling certain assets, including intellectual property assets.

•advance the NGN-401 program through clinical development and, if successful, seek regulatory approvals;

•seek regulatory approvals for any other product candidates that successfully complete clinical trials;

•incur additional legal, accounting and other expenses related to operating as a public company.

We do not have any products approved for commercial sale and have not generated any commercial revenue from product sales. Our ability to generate product revenue sufficient to achieve and maintain profitability will depend upon the successful development and eventual commercialization of one or more of our product candidates, which we expect, if it ever occurs, will take many years. We expect to spend a significant amount in development and marketing costs prior to such time. We will therefore require substantial additional capital to develop our product candidates and support our continuing operations. We may never succeed in achieving regulatory and marketing approval for our product candidates. We may obtain unexpected results from our preclinical and clinical trials. InFor example, in November 2024,2024 we announced that the Company doesdecided not expect to move forward with the NGN-101 CLN5 Batten disease gene therapy program atfor thisCLN5 time.Batten Givendisease, given the rarity of the disease,disease continued investment inand the programlack was predicated on alignment onof a streamlined registrational pathway with the FDA.FDA Tofollowing supportdenial aof streamlined pathway, we submitted anour RMAT application to the FDA. Despite our belieffor that the application met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT application was denied. We are currently evaluating options for the program. We may in the future elect to discontinue, delay, or modify additional preclinical and clinical trials of our other product candidates. A change in the outcome of any of these variables with respect to the development of a product candidate could mean a significant change in the costs and timing associated with the development of that product candidate. Accordingly, until such time that we can generate a sufficient amount of revenue from product sales or other sources, if ever, management expects to finance our operations through private or public equity or debt financings, loans or other capital sources, which could include income from collaborations, partnerships or other marketing, distribution, licensing or other strategic arrangements with third parties, or from grants. However, we may be unable to raise additional capital from these sources on favorable terms, or at all.all, Our failure to obtain sufficient capital on acceptable terms when neededwhich could have a material adverse effect on our business, results of operations or financial condition, including requiring us to delay, reduce or curtail our research, product development or future commercialization efforts. We may also be required to license rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose.business. Our management cannot provide assurance that we will ever generate positive cash flow from operating activities. See “Liquidity and Capital Resources.”

Uncertainty in the global economy presents significant risks to our business. We are subject to continued risks and uncertainties related to the current macroeconomic environment, including highpersistent inflation, highchanging interest rates, changes in foreign currency exchange rates, changes in trade policies, including tariffs or other trade restrictions or the threat of such actions, changes in domestic and global monetary and fiscal policy, recentthe bankenactment failures, proposed or adopted federal U.S. legislation seeking to limitof the provisionBIOSECURE Act in December 2025, which mandates a transition away from “biotechnology companies of servicesconcern,” rapid changes in ourthe sectorregulatory byand certainlegislative non-U.S.landscape entities,in the United States, geopolitical factors, including the ongoing conflicts between Russia and Ukraine and in the Middle East and the responses thereto, the impacts of climate change, and supply chain disruptions. While management is closely monitoring the impact of the current macroeconomic conditions on aspects of our business, including the impacts on our participants in our Phase 1/2 and Embolden clinical trial,trials, employees, suppliers, vendors and business partners, the ultimate extent of the direct and indirect impacts on our business remains highly uncertain and will depend on future developments and factors that continue to evolve. Most of these developments and factors are outside of our control and could exist for an extended period of time. Management will continue to evaluate the nature and extent of the potential impacts to our business, results of operations, liquidity and capital resources. For additional information, see the section entitled “Risk Factors.”

We have generated licensing revenue from the recognition of upfront payments received under agreements with third parties for the disposition of legacy Neoleukin assets (the “December 2023 CVR Licensing Agreement” and the “April 2024 CVR Licensing Agreement”) that are related to the legacy Neoleukin Therapeutics, Inc. (“Neoleukin”) business as part of the reverse merger.merger (the “Closing”). See Note 10,9, Commitments and Contingencies, for additional details regarding these licensing agreements.

We expect that our general and administrative expense will increase in the future to support our continued research and development activities,activities and potential commercialization efforts and increased costs of operating as a public company.efforts. These increases will likely include increased costs related to the hiring of additional personnel and fees to outside consultants, legal support and accountants, among other expenses. Additionally, we anticipate increased costs associated with being a public company, including expenses related to services associated with maintaining compliance with the requirements of Nasdaq and the SEC, insurance and investor relations costs. If any of our current or future product candidates obtains U.S. regulatory approval, we expect that we would incur significantly increased expenses associated with building a sales and marketing team, as well as an expanded regulatory and compliance function.

We assess our income tax positions and record tax benefits based upon management’s evaluation of the facts, circumstances, and information available at the reporting date. For those tax positions where it is more likely than not that a tax benefit will be sustained, we record the amount of tax benefit with a greater than 50 percent50% likelihood of being realized upon ultimate settlement with a taxing authority having full knowledge of all relevant information. For those income tax positions for which it is not more likely than not that a tax benefit will be sustained, no tax benefit is recognized in the financial statements.

LicensingWe did not generate any revenue wasfor the year ended December 31, 2025, as compared to $0.9 million for the year ended December 31, 2024, as compared to $0 for the year ended December 31, 2023.2024. We generated licensing revenue from the recognition of upfront payments received under the December 2023 CVR Licensing Agreement and the April 2024 CVR Licensing Agreement. Please see the section below entitled Other Expenses for a discussion on the related CVR liabilities.

Expenses related to the Rett syndrome program increased primarily due to a $5.2$6.7 million increase in clinical trial costs related to the Phase 1/2 and pivotal clinical trial of NGN-401 andNGN-401, a $1.2$3.6 million increase in chemistry, manufacturing and controls costs, partially offset by a $0.3$2.1 million decreaseincrease in preclinical costs.costs, and a $1.0 million increase in clinical development related expenses. The increasedecrease in expenses related to the Batten disease program was primarily driven by ana increasedecrease of $0.7$3.7 million in clinical trial related expenses, partiallya offsetdecrease byof $0.5 million in clinical development related expenses, and a decrease of $0.4$0.1 million in chemistry, manufacturing and controls costs.costs, due to the de-prioritization of the program. The increasedecrease in Early Discovery expenses was primarily driven by a $2.3$2.1 million increasedecrease in preclinical costs.

The increase in unallocated internal expenses was primarily driven by higher salaries, benefits, and stock-based compensation costs due to an increase in research and development headcount, as well as an increase in laboratory consumables expense related to chemistry, manufacturing and controls, partially offset by a decrease in wind-down expenses related to the Neoleukin reverse merger.controls.

We anticipate that our general and administrative expenses will increase in the future to support increased researchresearch, development and developmentprecommercial activities.

Interest income increased by $5.5$3.1 million for the year ended December 31, 2024,2025, as compared to the year ended December 31, 2023.2024. The increase was primarily due to a significant increase in the amount of our cash, cash equivalents and short-term investmentsinvestments, which was partially offset by a moderate decrease in interest rates.

Other expenses increaseddecreased by $1.5$1.3 million for the year ended December 31, 2024,2025, as compared to the year ended December 31, 2023.2024. The increasedecrease was primarily due to (i) an approximately $0.8 million accrual of contingent consideration liabilities related to the Intellectual Property CVR (as defined in Note 10,9, Commitments and Contingencies) in connection with the December 2023 Licensing Agreement and the April 2024 Licensing Agreement and (ii) an approximately $0.4$0.3 million accrual of a contingent consideration liability related to the Sales Tax CVR for an anticipated sales tax refund from Washington state andin (iii)the prior period. This was partially offset by an approximate $0.4$0.1 million accrualadjustment to the contingentsales considerationtax liabilityrefund relatedfrom toWashington state for the Intellectualyear Propertyended CVRDecember to31, offset permitted deductions under the CVR agreement.2025.

As of December 31, 2024,2025, we had cash, cash equivalents and short-term investments totaling $312.4$269.0 million. Since inception and through the issuance of these financial statements, we have funded our operations primarily through private placementssales of convertiblepreferred preferredstock, common stock and commonpre-funded stockwarrants for net proceeds of approximately $521.9$552.1 million.

•We are substantially dependent on the success of our most advanced product candidate, NGN-401, and our ongoing clinical trial of NGN-401 may not be successful.

•NGN-401 is in clinical development and our otherpreclinical programs are in early stages of development and may fail in development or suffer delays that materially and adversely affect their commercial viability. If we are unable to complete development of, or commercialize, our product candidates, or experience significant delays in doing so, our business will be materially harmed.

•We have a number of academic collaborations, and currently rely on our collaboration with the University Court of the University of Edinburgh for certain aspects of our preclinical research and development programs, including working in collaboration to discover and preclinically develop potential product candidates for our near-term future pipeline. Failure or delay of the University of Edinburgh or any other collaborator to fulfilfulfill all or part of its obligations under our agreements, a breakdown in collaboration between the parties or a complete or partial loss of the relationship would materially harm our business.

•The regulatory approval processes of the U.S. Food and Drug Administration (“FDA”) and other comparable foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable. If we are not able to obtain, or if there are delays in obtaining, required regulatory approvals for our product candidates, or if we determine that we are not willing or able to complete the regulatory approval process given the resources required to do so, we will not be able to commercialize, or will be delayed in commercializing, such product candidates, and our ability to generate revenue will be materially impaired.

We are a clinical-stage biotechnology company with limited operating history. Since our inception in 2018, we have incurred significant operating losses and have used substantially all of our resources to conduct research and development activities, preclinical studies, Phase 1/2 clinical trials of our most advanced product candidates as well as aour Phase 3 pivotalEmbolden trial for NGN-401, establish in-house manufacturing capabilities, including analytical and process development operations to support ongoing manufacturing operations, manufacture product candidates, conduct business planning, develop and maintain our intellectual property portfolio, hire personnel, raise capital, and provide general and administrative support for these activities. We have limited experience as a company in initiating, conducting or completing clinical trials. In part because of this lack of experience, we cannot be certain that our current and planned clinical trials will begin on time, meet our anticipated timelines for enrollment and data analysis, or be completed on time, if at all. In addition, while we have completed enrollmentdosing in the Embolden trial and the Phase 1/2 clinical trial offor NGN-401 in patients with Rett syndrome, initiated dosing in our EmboldenTM registrational trial for NGN-401 and completed enrollment in a Phase 1/2 clinical trial of NGN-101 in patients with CLN5 Batten disease, we have not yet demonstrated our ability to successfully complete clinical trials (including Phase 3 or other pivotal clinical trials), obtain regulatory or marketing approvals, manufacture a commercial-scale product or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization. Additionally, we expect our financial condition and operating results to continue to fluctuate significantly from period to period due to a variety of factors, many of which are beyond our control. Consequently, any predictions made about our future success or viability may not be as accurate as they could be if we had a longer operating history.

Developing biotechnology products is a long, time-consuming, expensive and uncertain process that takes years to complete. Since our inception, we have funded our operations primarily through privateequity financings and have incurred significant recurring losses, including a cumulative net loss from inception through MarchJune 31,30, 2026 of $383.6$418.1 million. We expect ourto continue incurring significant expenses to increase in connection with our ongoing activities, particularlyincluding withcontinued respectpatient tomonitoring activities for our ongoing Embolden registrational clinical trial of NGN-401 in patients with Rett syndrome, with the expectation that we will also initiate additional clinical trials in the future, and continue to research, develop and conduct preclinical studies of our other potential product candidates. We also anticipate that we may have near term expenses related to NGN-101 as we continue to evaluate options for the program following the denial by the FDA of a Regenerative Medicine Advanced Therapy (“RMAT”) designation, which precludes our ability to use a streamlined registrational pathway necessary for further investment in the program.

We have incurred and expect to continue to incur additional costs associated with operating as a public company, and we do not anticipate achieving any significant revenue in the near term given the development stage of our product candidates. Accordingly, we will require substantial additional funding to continue our operations. Based on our current operating plan, we believe that our existing cash, cash equivalents and short-term investments should be sufficient to fund our operations throughinto the first quarter of 2028.2029. This estimate is based on assumptions that may prove to be materially wrong, and we could deplete our available capital resources sooner than we currently expect. Our future capital requirements will depend on many factors, including:

•the number and scope of preclinical and clinical programs we pursue to develop our gene therapy candidate pipeline and EXACT (Expression Attenuation via Construct Tuning)EXACTTM platform;

•the scale up of our clinical and regulatory capabilities, including establishing our current good manufacturing practices (“cGMP”) manufacturing capabilities to support expansion of our pipeline and future registration-enabling clinical trials, obtaining cGMP material for clinical trials or potential commercial sales, and performing Process Performance Qualification (“PPQ”) testing to demonstrate consistent quality in our manufacturing process;

We do not have any committed external sources of funds. We have filed an S-3 Registration Statement for the sale of up to $300.0 million in any combination of our common stock, preferred stock, debt securities, warrants or units, and may conduct one or more sales of securities pursuant to such registration statement from time to time. On July 2, 2026, we closed an underwritten public offering of shares of our common stock and prefunded warrants to purchase our common stock registered under the shelf registration statement (the “July 2026 Offering”), resulting in proceeds of approximately $134.8 million after deducting underwriting discounts and commissions and other estimated offering expenses. We have also entered into an at the market (“ATM”) Sales Agreement (the “Sales Agreement”) with Leerink Partners LLC (“Leerink”), pursuant to which, as of MarchJune 31,30, 2026, we have sold $31.0$37.1 million in shares of common stock, resulting in proceeds of $30.1$36.0 million after deducting sales commissions and other offering expenses. We may in the future, from time to time, offer and sell through Leerink up to an additional $119.0$112.9 million of the common stock registered under the shelf registration statement, pursuant to one or more “at the market” offerings. However, sales of our common stock under the Sales Agreement with Leerink are subject to business, economic or competitive uncertainties and contingencies, and adequate additional financing may not be available to us on acceptable terms, or at all. We may be required to or choose to seek additional funds sooner than planned through public or private equity offerings, debt financings, collaborations and licensing arrangements or other sources. Such financings may dilute our stockholders or the failure to obtain such financing may restrict our operating activities. Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our business. To the extent that we raise additional capital through the sale of equity or convertible debt securities, yourexisting stockholders ownership interest will be diluted, and the terms may include liquidation or other preferences and anti-dilution protections that adversely affect yourthe rights asof aexisting stockholder.stockholders. Debt financing may result in imposition of debt covenants, increased fixed payment obligations or other restrictions that may affect our business. If we raise additional funds through upfront payments or milestone payments pursuant to future collaborations with third parties, we may have to relinquish valuable rights to product development programs, or grant licenses on terms that are not favorable to us. Additional capital may not be available in sufficient amounts or on reasonable terms, if at all. Our ability to raise additional capital may be adversely impacted by global macroeconomic conditions, including volatility in interest rates, escalating trade tensions and restrictions, tariffs, geopolitical instability, changes in government regulations and significant volatility in the credit and financial markets in the United States and worldwide, particularly in the biotechnology and biopharmaceutical industries, over which we may have no or little control. Our failure to raise capital as and when needed or on acceptable terms would have a negative impact on our financial condition and our ability to pursue our business strategy, and we may have to delay, reduce the scope of, suspend or eliminate clinical trials, product development programs or future commercialization efforts.

We have incurred significant net losses in each period since we commenced operations in 2018. Our net loss was $30.9$65.4 million for the threesix months ended MarchJune 31,30, 2026 and our cumulative net loss from inception as of MarchJune 31,30, 2026 was $383.6$418.1 million. We expect to continue to incur significant losses for the foreseeable future. Our operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially if and as we:

Our future success is substantially dependent on our ability to timely obtain marketing approval for, and then successfully commercialize, our most advanced product candidate, NGN-401. We are investing a majority of our efforts and financial resources into the research and development of this product candidate, as we are currently conducting a registrational clinical trial of NGN-401 in patients with Rett syndrome (our Embolden trial) and commencedcompleted dosing patients in that trial in the fourthsecond quarter of 2025.2026.

As described in “Business—Competition” in our Annual Report on Form 10-K, our competitors have developed, are developing or may develop programs or clinical stageclinical-stage products competitive with NGN-401 or our other earlier stage product candidates. Competitive therapeutic treatments include those that have already been approved and accepted by the medical community for Rett syndrome and any new treatments for Rett syndrome. Our success will depend partially on our ability to develop and commercialize products that have a competitive safety, efficacy or potency, dosing and/or presentation profile. Our commercial opportunity and success will be reduced or eliminated if competing products are safer, more effective or potent, have a more attractive or less invasive dosing profile or presentation or are less expensive than any products we may develop, or if competitors develop competing products that enter the market more quickly than we are able to, if we are able to at all, and are able to gain market acceptance.

We have no products on the market and while we have completed enrollmentdosing in our Phase 1/2 clinical trial of NGN-401 and initiated dosing in our Embolden registrational trial, NGN-401 is still in the clinical development stage. In addition, we have disclosed that unless we are able to find an alternative pathway for advancement, we will need to discontinue our NGN-101 program following the denial of RMAT designation for NGN-101 by the FDA, which would preclude a streamlined path to regulatory approval.

Trials may be subject to delays as a result of patient enrollment taking longer than anticipated or patient withdrawal. We may not be able to initiate or continue clinical trials for our product candidates if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA, the Medicines and Healthcare products Regulatory Agency (“MHRA”) in the United Kingdom, the Therapeutic Goods AssociationAdministration (“TGA”) in Australia, the European Medicines Agency (“EMA”) or other foreign regulatory authorities. We cannot predict how successful we will be at enrolling subjects in future clinical trials. Subject enrollment is affected by other factors including:

•the perceived risks and benefits of the product candidate in the trial, especially by clinician experts and patient advocacy organizations, including relating to AAV9-based gene therapy, which may evolve over time as more AAV-based gene therapy trials are conducted, and intracerebral spinalintra-cerebrospinal fluid delivery system;

In November 2024, we announced that we do not expect to move forward with the NGN-101 CLN5 Batten disease gene therapy program at the present time because of an inability to align on a streamlined registrational pathway with the FDA for that product candidate, but that we would continue to evaluate options for that program. We may consider a range of potential alternatives for the program, which could include continuing to discuss possibilities for a streamlined pathway to registration with the FDA, looking for a partnerpartner, or out-licensing the product candidate entirely, but there can be no assurance that we will find any alternative to move the program forward.

The discovery and development of therapeutics for patients with neurological diseases is an emerging field, and the scientific discoveries that form the basis for our efforts to discover and develop product candidates are relatively new. The scientific evidence to support the feasibility of developing product candidates based on these discoveries is both preliminary and limited. Although we believe, based on our preclinical work, that our programs have the potential to be disease-modifying therapies, clinical results may not confirm this hypothesis or may only confirm it for certain alterations or certain indications. The patient populations for our product candidates are limited to those with specific neurological diseases. We cannot be certain that the patient populations for each specific disease will be large enough to allow us to successfully obtain approval and commercialize our product candidates and achieve profitability. Further, our clinical trial of NGN-401 involves a small patient population. Because of the small sample sizes, the expansion of our clinical trial to an adolescent/adult cohort and the heterogeneity of the disease state, the results of thisthe Phase 1/2 trial for NGN-401 may not be indicative of results of the Embolden trial or any future clinical trials. In particular, whiletrials we havemay expanded the clinical trial of NGN-401 to include adolescent and adult patients in both our Phase 1/2 trial and our Embolden registrational trial, our interim data releases to date have focused solely on pediatric participants in those trials, and we cannot be sure that the results that we have reported in our pediatric population of that trial will be representative of our adolescent or adult participants.conduct.

We cannot be sure that the FDA or comparable foreign regulatory authorities will agree with our clinical development plan. We have completed enrollmentdosing in our Phase 1/2 clinical trial of NGN-401 in patients with Rett syndrome and have commenced dosing in our Embolden registrational trial for NGN-401. However, if the FDA or any comparable regulatory authorities require us to conduct additional trials or enroll additional patients, our development timelines may be delayed, or we may not be able to pursue further development due to such delays. For example, in November 2024, we announced that we do not expect to move forward with the NGN-101 for CLN5 Batten disease gene therapy program at this time. Given the rarity of the disease, continued investment in the program was predicated on alignment on a streamlined registrational pathway with the FDA. To support a streamlined pathway, we submitted an RMAT application to the FDA. Despite our belief that we met the standard of preliminary clinical evidence required to obtain an RMAT designation, the RMAT application was denied. We cannot be sure that submission of an IND application, clinical trial application (“CTA”) or similar application will result in the FDA or comparable foreign regulatory authorities, as applicable, allowing clinical trials to begin in a timely manner, if at all. Moreover, even if these trials begin, issues may arise that could cause regulatory authorities to require us to suspend or terminate such clinical trials. Events that may prevent successful or timely initiation or completion of clinical trials include: inability to generate sufficient preclinical, toxicology or other in vivo or in vitro data to support the initiation or continuation of clinical trials; delays in reaching a consensus with regulatory authorities on study design or implementation of the clinical trials; delays or failure in obtaining regulatory authorization to commence a trial; delays in reaching agreement on acceptable terms with prospective CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and clinical trial sites; delays in identifying, recruiting and training suitable clinical investigators; delays in obtaining required IRB approval at each clinical trial site; difficulties in patient enrollment in our clinical trials for a variety of reasons; delays related to safety concerns; delays in manufacturing, testing, releasing, validating or importing/exporting sufficient stable quantities of our product candidates for use in clinical trials or the inability to do any of the foregoing; failure by our CROs, other third parties or us to adhere to clinical trial protocols; failure to perform in accordance with the FDA’s or any other regulatory authority’s good clinical practices (“GCPs”) or applicable regulatory guidelines in other countries; changes to the clinical trial protocols; clinical sites deviating from trial protocol or dropping out of a trial; changes in regulatory requirements and guidance that require amending or submitting new clinical protocols; selection of clinical endpoints that require prolonged periods of observation or analyses of resulting data; transfer of manufacturing processes to larger-scale facilities operated by a CDMO and delays or failure by our CDMOs or us to make any necessary changes to such manufacturing process and demonstrate comparability to materials used in earlier clinical phases; and third parties being unwilling or unable to satisfy their contractual obligations to us.

In addition, even if we are able to successfully complete the clinical trial for NGN-401, we cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. This is particularly true for clinical trials in very rare diseases, such as with our Embolden registrational trial of NGN-401 for the treatment of Rett syndrome, where the very small patient population makes it difficult to conduct two traditional, adequate and well-controlled studies. In such cases, the FDA or comparable foreign regulatory authorities are often required or permitted to exercise flexibility in approving therapies for such diseases, but obtaining flexibility is uncertain and may never occur. Moreover, results acceptable to support approval in one jurisdiction may be deemed inadequate by another regulatory authority to support regulatory approval in the other jurisdiction. To the extent that the results of the trials are not satisfactory to the FDA or applicable regulatory authorities for support of a marketing application, we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates.

From time to time, we may publicly disclose preliminary, interim or topline data from our preclinical studies and clinical trials, which are based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a more comprehensive review of the data. We also make assumptions, estimations, calculations and conclusions as part of our analyses of these data without the opportunity to fully and carefully evaluate complete data. Preliminary, interim or topline results also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary data previously disclosed. These preliminary, interim or topline data 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 or as patients from our clinical trials continue other treatments. For example, in June 2024, we announced initial safety data related to the dosing of our first fourthree participants at the 1E15 vg dose and the first participant at the 3E15 vg dose in our Phase 1/2 clinical trial of NGN-401 for the treatment of Rett syndrome which suggested a favorable safety profile for the 1E15 vg dose.profile. In November 2024, an SAE was reported in a participant who received the 3E15 vg dose, which caused us to revise our assumptions regarding the safety profile of the 3E15 vg dose. Because of this potential for change, preliminary, interim and topline data should be viewed with caution until final data are available. Further, others, including regulatory agencies, may not accept or agree with our assumptions, estimates, calculations, conclusions or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular product candidate, the approvability or commercialization of a particular product candidate and our company in general. In addition, the information we choose to publicly disclose regarding a particular preclinical study or clinical trial is based on what is typically extensive information, and you or others may not agree with what we determine is material or otherwise appropriate information to include in our disclosure. If the preliminary, interim or topline data that we report differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, our ability to obtain approval for, and commercialize, NGN-401 or any other product candidate may be harmed, which could harm our business, operating results, prospects or financial condition. In addition, differences between preliminary, interim or topline data and final data could significantly harm our business prospects and may cause the trading price of our common stock to fluctuate significantly.

We have expended substantial efforts and costs testing our EXACT technology in preclinical studies of NGN-401, including completing toxicology studies prior to the FDA providing clearance of the IND for NGN-401 and have not seen any adverse effects that we believe are attributable to EXACT in our Phase 1/2 trial of NGN-401 as of our most recent data cut off date of OctoberJune 30,16, 2025.2026. However, we cannot guarantee that significant adverse effects will not be seen in the future in clinical trials for NGN-401, which could result in clinical holds, delays, suspension or withdrawal of our IND. If any of the foregoing events occur or if NGN-401, NGN-101 or any other product candidates prove to be unsafe, our entire pipeline could be affected, which would have a material adverse effect on our business, financial condition, results of operations and prospects.

We are early in our development efforts and will need to successfully complete later-stage and pivotal clinical trials in order to obtain FDA or comparable foreign regulatory approval to market our product candidates. Carrying out clinical trials and the submission of a successful IND or CTA is a complicated process. Even though our product candidate NGN-401 for Rett syndrome has been accepted into the FDA’s START program and granted Breakthrough Therapy and RMAT designations, the combination of which is expected to allow access to frequent advice from FDA staff, intensive guidance on efficient drug development and eligibility for an Accelerated Approval pathway and Priority Review, our lack of experience with FDA submissions may still slow our progress towards FDA approval. We have completed enrollmentdosing in both our Phase 1/2 trial of NGN-101 for the treatment of CLN5 Batten disease and our Phase 1/2 clinicaland trialEmbolden trials of NGN-401 for the treatment of Rett syndrome and have commenced dosing in our Embolden registrational trial for NGN-401 in the United States; however, we have not yet completed a Phase 1/2 clinical trial and have limited experience as a company in preparing, submitting and prosecuting regulatory filings. We expect to engage with foreign regulators to determine the requirements to support initiation of a pivotal clinical trial in foreign countries; however, those regulatory authorities may have different requirements for approval, including different requirements for clinical trial designs, and may recommend or require changes to the study design for NGN-401, including the number and size of registrational clinical trials required to be conducted in that program to be considered for approval. Regulatory authorities could also require manufacturing changes or have us implement additional analytical processes prior to initiation of a future clinical trial. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to regulatory submission and approval of our product candidates or we may determine that the regulatory requirements for submission are too burdensome to support continued development of one or more of our product candidates, as we did with our NGN-101 product candidate for CLN5 Batten disease, which we do not plan to move forward with due to a lack of alignment with the FDA on a streamlined pathway to registration. Additionally, even if regulatory authorities agree with the design and implementation of the clinical trials set forth in a regulatory meeting, such regulatory authorities may change their requirements in the future. The FDA or comparable foreign regulatory authorities may require the analysis of data from trials assessing different doses of the product candidate alone or in combination with other therapies to justify the selected dose prior to the initiation of large trials in a specific indication. Any delays or failure to initiate clinical trials or obtain regulatory approvals for our trials may prevent us from completing our clinical trials or commercializing our products on a timely basis, if at all. We are subject to similar risks related to the review and authorization of our protocols and amendments by comparable foreign regulatory authorities.

We have a GMP manufacturing facility located in Houston, Texas that includes process, analytical and bioanalytical development labs with experienced teams. NGN-401 was manufactured at our Houston facility and clinical-grade product was used for dosing in the Phase 1/2 clinical trial of NGN-401 and is being used for dosing in the Embolden trial. While we have adequate material for our NGN-401 clinical trial program, weWe expect to conduct manufacturing campaigns in the future to generate supply of other product candidates for our preclinical studies for our discovery programs, andhowever we may not be able to satisfy such supply through production at our own facility and may need to outsource some or all of our production work.

We have a number of academic collaborations, and currently rely on our collaboration with the University of Edinburgh for certain aspects of our preclinical research and development programs, including working in collaboration to discover and preclinically develop our potential product candidates for our near-term future pipeline. Failure or delay of the University of Edinburgh or any other collaborator to fulfilfulfill all or part of its obligations under our agreements, a breakdown in collaboration between the parties or a complete or partial loss of the relationship would materially harm our business.

Further, under the MCA, the University of Edinburgh is primarily responsible for prosecuting and maintaining our licensed intellectual property, and it may fail to properly prosecute, maintain or defend such intellectual property. In such event, if we are unable to otherwise maintain or defend such intellectual property, we could face the potential invalidation of the intellectual property or be subjected to litigation or arbitration, any of which would be time-consuming and expensive. To enforce the licensed intellectual property rights under the MCA, we will need to coordinate with the University of Edinburgh, which could slow down or hamper our ability to enforce our licensed intellectual property rights. If this happens, we could face increased competition that could materially and adversely affect our business. For a further description of the MCA, see Part II, Item 7 of this Annual Report on Form 10-K titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations—License and Collaboration Agreements.”

We have engaged CROs or other third parties to conduct preclinical and IND enabling studies and our clinical trials, including our Phase 1/2 clinical trial and our Embolden registrational trial of NGN-401. We currently use CDMOs to provide certain research-grade materials and to assist in preparation for a potential Biologics License Application submission to the FDA, and may in the future use CDMOs for future clinical trials for other product candidates or in the manufacture and distribution of commercial products if we are successful in gaining regulatory approval for any of our product candidates.

Our ability to compete in the highly competitive biotechnology and pharmaceutical industries depends upon our ability to attract and retain highly qualified managerial, scientific and medical personnel. We are highly dependent on our managerial, scientific and medical personnel, including our Founder and Chief Executive Officer, President and Chief Financial Officer, Chief Medical Officer, Chief Scientific Officer, Chief Commercial Officer and Senior Vice President of Technical Operations, as well as other key members of our leadership team. Our executive officers and other key personnel may terminate their employment with us at any time. We do not maintain “key person” insurance for any of our executives or other employees. The loss of the services of our executive officers or other key employees could impede the achievement of our research, development and commercialization objectives and seriously harm our ability to successfully implement our business strategy. Furthermore, replacing executive officers and key personnel may be difficult and may take an extended period of time. Failure to attractingattract and retainingretain qualified personnel could materially and adversely affect our business, financial condition and results of operations. We could in the future have difficulty attracting and retaining experienced personnel and may be required to expend significant financial resources on our employee recruitment and retention efforts.

We, and third parties with whom we work, are or may become subject to numerous domestic and foreign laws, regulations, and standards relating to privacy, data protection, and data security, the scope of which areis changing, subject to differing applications and interpretations, and may be inconsistent among countries, or conflict with other rules. For example, the BIOSECURE Act, enacted in December 2025, restricts the ability of federal agencies and their contractors to work with designated “biotechnology companies of concern.” The implementation of this Act, including the forthcoming publication of a comprehensive list of restricted entities by the Office of Management and Budget, may require us to terminate or transition existing relationships with certain third-party service providers, which could disrupt our data processing capabilities or clinical trial operations. We are or may become subject to the terms of contractual obligations related to privacy, data protection, and data security. Our obligations continue to change and expand as our business grows, particularly with the proliferation of state-level comprehensive privacy laws in the U.S. The actual or perceived failure by us or third parties related to us to comply with such laws, regulations and obligations could increase our compliance and operational costs, expose us to regulatory scrutiny, actions, fines and penalties, result in reputational harm, lead to a loss of customers, result in litigation and liability, subject us to injunctive restrictions on data processing, adversely impact our ability to appropriately manage third parties with whom we work and otherwise cause a material adverse effect on our business, financial condition, and results of operations. See “Business—Government Regulation—Data Privacy and Security” and “—Other Regulatory Matters” in our Annual Report on Form 10-K for a more detailed description of the laws that may affect our ability to operate.

As of December 31, 2025, we had net operating loss (“NOL”) carryforwards for federal and state income tax purposes of $372.2 million and $43.5 million, respectively. The federal NOLs will not be subject to expiration and can be carried forward indefinitely; however, they are limited to a deduction to 80% of annual taxable income. The state NOLs begin to expire in 2029. To the extent that our taxable income exceeds any current year operating losses, we plan to use our carryforwards to offset income that would otherwise be taxable. Also, for state income tax purposes, the extent to which states will conform to the federal laws is uncertain and there may be periods during which the use of NOL carryforwards areis suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. In addition, under Section 382 of the Code, changes in our ownership may limit the amount of our NOL carryforwards and tax credit carryforwards that could be utilized annually to offset our future taxable income, if any. This limitation would generally apply in the event of a cumulative change in ownership of more than 50% (as measured by value) among a stockholder or one or more groups of stockholders who own at least 5% of our stock within a three-year period. We have not performed an analysis to determine whether there has been an ownership change pursuant to Section 382. Any such limitation may significantly reduce our ability to utilize our NOL carryforwards and tax credit carryforwards before they expire. Any such limitation, whether as the result of a public offering, private placements, sales of our common stock by our existing stockholders or additional sales of our common stock by us, could have a material adverse effect on our results of operations in future years.

We rely and expect to continue to rely upon a combination of patents, trademarks, trade secret protection and confidentiality agreements to protect the intellectual property related to our product candidates and technologies and to prevent third parties from unfairly competing with us. Our success depends in large part on our ability to obtain and maintain patent protection for platform technologies, including our EXACT transgene regulation platform, product candidates and their uses, as well as the ability to operate without infringing on or violating the proprietary rights of others. As of MarchJune 31,30, 2026, we license 3032 patent applications, including U.S. patent applications, international patent applications under the Patent Cooperation Treaty or otherwise, and expect to continue to file patent applications in the United States and abroad related to discoveries and technologies that are important to our business. However, we may not be able to protect our intellectual property rights throughout the world and the legal systems in certain countries may not favor enforcement or protection of patents, trade secrets and other intellectual property. Filing, prosecuting and defending patents on product candidates worldwide would be prohibitively expensive and our intellectual property rights in some foreign jurisdictions may be less extensive than those in the United States. As such, we do not have patents in all countries or all major markets and may not be able to obtain patents in all jurisdictions even if we apply for them. Competitors may operate in countries where we do not have patent protection and could then freely use our technologies and discoveries in such countries to the extent such technologies and discoveries are publicly known or disclosed in countries where patent protection has not been requested. In addition, competitors may be able to design around our patents to create technologies that directly compete with ours without infringing our intellectual property.

Our intellectual property portfolio is at an early stage. As of MarchJune 31,30, 2026, our licensed intellectual property only includes four issued patents, all of which are related to our NGN-101 program which we are no longer actively pursuing. Our pending and future patent applications may not result in patents being issued. Any issued patents may not afford sufficient protection of our product candidates or their intended uses against competitors, nor can there be any assurance that the patents issued will not be infringed, designed around, invalidated by third parties, or effectively prevent others from commercializing competitive technologies, products or product candidates. Even if these patents are granted, they may be difficult to enforce. Further, any issued patents that may be licensed or owned covering our product candidates could be narrowed or found invalid or unenforceable if challenged in court or before administrative bodies in the United States or abroad, including the United States Patent and Trademark Office (“USPTO”). Further, if we encounter delays in any clinical trials or delays in obtaining regulatory approval, the period of time during which we could market product candidates under patent protection would be reduced. Thus, the patents that we may own or license may not afford any meaningful competitive advantage.

In addition to seeking patents for some of our technology and product candidates, we may also rely on trade secrets, including unpatented know-how, technology and other proprietary information, to maintain our competitive position. Any disclosure, either intentional or unintentional, by our employees, the employees of third parties with whom we share facilities or third-party consultants and vendors that we engage to perform researches,research, clinical trials or manufacturing activities, or misappropriation by third parties (such as through a cybersecurity breach) of our trade secrets or proprietary information could enable competitors to duplicate or surpass our technological achievements, thus eroding our competitive position in the market. In order to protect our proprietary technology and processes, we rely in part on confidentiality agreements with collaborators, employees, consultants, outside scientific collaborators and sponsored researchers and other advisors. These agreements may not effectively prevent disclosure of confidential information and may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. We may need to share our proprietary information, including trade secrets, with future business partners, collaborators, contractors and others located in countries at heightened risk of theft of trade secrets, including through direct intrusion by private parties or foreign actors and those affiliated with or controlled by state actors. In addition, while we undertake efforts to protect our trade secrets and other confidential information from disclosure, others may independently discover trade secrets and proprietary information, and in such cases, we may not be able to assert any trade secret rights against such party. Costly and time-consuming litigation could be necessary to enforce and determine the scope of our proprietary rights and failure to obtain or maintain trade secret protection could adversely affect our competitive business position.

Our current or future licensors may have relied on third-party consultants or collaborators or on funds from third parties, such as the U.S. government or academic institutions, such that our licensors are not the sole and exclusive owners of the patents we in-licensed. If other third parties have ownership rights or other rights to our in-licensed patents, they may be able to license such patents to our competitors, and our competitors could market competing products and technology. This could have a material adverse effect on our competitive position, business, financial conditions, operations, and prospects.

Certain of the intellectual property rights we have licensed are generated through the use of U.S. government funding and are therefore subject to certain federal regulations. As a result, the U.S. government may have certain rights to intellectual property embodied in our current or future product candidates pursuant to the Bayh-Dole Act of 1980 (the “Bayh-Dole Act”) and implementing regulations. These U.S. government rights in certain inventions developed under a government-funded program include a non-exclusive, non-transferable, irrevocable worldwide license to use inventions for any governmental purpose. In addition, the U.S. government has the right to require ourus or our licensors’ to grant exclusive, partially exclusive, or non-exclusive licenses to any of these inventions to a third party if it determines that: (i) adequate steps have not been taken to commercialize the invention; (ii) government action is necessary to meet public health or safety needs; or (iii) government action is necessary to meet requirements for public use under federal regulations (also referred to as “march-in rights”). The U.S. government also has the right to take title to these inventions if we fail, or the applicable licensor, fails to disclose the invention to the government and fails to file an application to register the intellectual property within specified time limits. These time limits have recently been changed by regulation, and may change in the future. Intellectual property generated under a government funded program is also subject to certain reporting requirements, compliance with which may require us or the applicable licensor to expend substantial resources. In addition, the U.S. government requires that any products embodying the subject invention or produced through the use of the subject invention be manufactured substantially in the United States. The manufacturing preference requirement can be waived if the owner of the intellectual property can show that reasonable but unsuccessful efforts have been made to grant licenses on similar terms to potential licensees that would be likely to manufacture substantially in the United States or that under the circumstances domestic manufacture is not commercially feasible. This preference for U.S. manufacturers may limit our ability to contract with non-U.S. product manufacturers for products covered by such intellectual property. To the extent any of our current or future intellectual property is generated through the use of U.S. government funding, the provisions of the Bayh-Dole Act may similarly apply.

Since the start of President Trump’s administration in 2025 (the “Trump Administration”), U.S. policy changes have been implemented at a rapid pace and additional change is likely. It is difficult to predict how executive actions that may be taken under the currentTrump administration may affect the FDA’s ability to exercise its regulatory authority. If any actions impose constraints on the FDA’s ability to engage in routine oversight and product review activities in the normal course, our business may be negatively impacted. Additionally, the Trump Administration or other parts of the federal government could adopt legislation, regulations or policies that adversely affect our business or create a more challenging and costly environment to pursue the development, approval and commercialization of our product candidates. Recent developments at the FDA include announcement of a plan to phase out animal testing for monoclonal antibodies and certain other drugs, the proposedintroduction rareof diseasethe evidenceRare principlesDisease programEvidence Principles process to facilitate approval of drugs to treat rare diseases with very small patient populations with significant unmet medical need and with a known genetic defect that is the major driver of the pathophysiology, and the announcement of a new Commissioner’s National Priority Voucher program for companies supporting certain U.S. national health priorities and interests. ToWe themay extentnot our competitors are selected for this new voucher pilot program, or are otherwisebe able to participate in any of these initiatives intended to accelerate drug development and application review,review. To the extent our competitors are able to participate in such initiatives and obtain faster approval than us, our competitive position may be harmed.

Our product candidates will need to meet safety, purity and efficacy or potency standards applicable to any new biologic under the regulatory framework administered by the FDA. In addition to FDA oversight and oversight by IRBs under guidelines promulgated by the National Institutes of Health (“NIH”), gene therapy clinical trials are also subject to review and oversight by an institutional biosafety committee (“IBC”), a local institutional committee that reviews and oversees research utilizing recombinant or synthetic nucleic acid molecules at that institution. The IBC assesses the safety of the research and identifies any potential risk to public health or the environment. 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. Although the FDA decides whether individual gene therapy protocols may proceed, the review process and determinations of other reviewing bodies can impede or delay the initiation of a clinical trial, even if the FDA has reviewed the trial and approved its initiation.

Adverse developments in preclinical studies or clinical trials conducted by others in the field of gene therapy and gene regulation products may cause the FDA, the EMA, and other regulatory authorities to revise the requirements for approval of any product candidates we may develop or limit the use of products utilizing gene regulation technologies, either of which could harm our business. In addition, the clinical trial requirements of the FDA, the EMA, and other regulatory authorities and the criteria these regulators use to determine the safety, purity and efficacy or potency of a product candidate vary substantially according to the type, complexity, novelty, and intended use and market of the potential products. Because of this complexity, even though our product candidate NGN-401 for Rett syndrome has been accepted into the FDA’s START programprogram, Breakthrough Therapy Designation and the RMAT program, which we expect together will allow us to have access to more frequent advice from FDA staff, intensive guidance on efficient drug development and eligibility for an Accelerated Approval pathway and Priority Review, the regulatory approval process for product candidates such as those being developed by us can be more expensive and take longer than for other, better known, or more extensively studied pharmaceutical or other product candidates. Further, as we are developing novel potential treatments for diseases in which, in some cases, there is little clinical experience with potential new endpoints and methodologies, heightened risk that the FDA, the EMA or other regulatory authorities may not consider the clinical trial endpoints to provide clinically meaningful results, and the resulting clinical data and results may be more difficult to analyze. In addition, we may not be able to identify or develop appropriate animal disease models to enable or support planned clinical development. Any natural history studies that we may conduct or rely upon in our clinical development may not be accepted by the FDA, EMA or other regulatory authorities. Regulatory agencies administering existing or future regulations or legislation may not allow production and marketing of products utilizing gene regulation technology in a timely manner or under technically or commercially feasible conditions. In addition, regulatory action or private litigation could result in expenses, delays, or other impediments to our research programs or the commercialization of resulting products. Further, approvals by one regulatory agency may not be indicative of what other regulatory agencies may require for approval.

The FDA has recently required additional and in some cases more stringent clinical trial designs and clinical trial data for gene therapy product candidates, even where companies believed they had previously established alignment with the FDA on their trial designs. If the FDA were to change its position regarding elements of our clinical trial design or the clinical data required to support approval of our product candidates, we may face additional expenses or challenges in gaining approval of such products.

From time to time, the FDA may provide written feedback on clinical trial design elements, including for instance an indication that it would be willing to consider a regulatory pathway based on limited clinical data, such as data from an early stage or single pivotal study, or based on data using historical or other controls. However, even if it has provided this guidance in writing, the FDA retains broad discretion to revise or withdraw such guidance with respect to any design elements of our clinical development plan at any time. Even if the FDA initially agrees that a particular data set or development plan could support a marketing application, the agency could later determine that additional or more comprehensive clinical evidence is required. Recently, theThe FDA has required certain gene therapy companies who are seeking BLA approval for product candidates to produce additional data with more stringent requirements than were included in the initial clinical trial design, including in some instances data that may require that company to conduct additional clinical trials. While we have recently achieved concordance with the FDA on our clinical trial designs for our Phase 3 Embolden trial of NGN-401, the continued disruptions and changes in leadership at the FDA create ongoing uncertainty about what evidentiary standards may be applied in the future,future. If we were to experience a change in the FDA’s position related to our trial design, especially with respect to our Embolden clinical trial, we expect such a change could delay or prevent approval, increase our development costs, and adversely affect our ability to commercialize our product candidates.

The ability of the FDA and other regulatory authorities to review and approve regulatory submissions can be affected by a variety of factors, including statutory, regulatory and policy changes, inadequate government budget funding levels, their ability to accept user fees, or a reduction in the FDA’s workforce and its ability to hire and retain key personnel, disruptions caused by government shutdowns and public health crises. There have beenFollowing mass layoffs of federal government employees sinceat the start of the Trump Administration in January 2025, the fullFDA impactwarned of whichpotential remainsdelays unclear.in Averagereview of new applications, and average review times at the agency have fluctuated as a result. While the FDA in June 2026 announced plans to hire over 2,000 new employees, there may be continued disruption in the work of the agency due to the previous terminations and the resources required to hire and integrate new employees. 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. TheThere Trumphave Administrationalso has madebeen and is expected tomay continue to makebe changes in the leadership of various U.S. federal regulatory agencies.agencies, including the FDA. For instance, thein FDAApril recently announced2026 the expectedhead of CBER left the FDA, followed shortly thereafter by the termination of the subsequent acting head of CBER in May 2026 as well as the departure of the FDA Commissioner in May 2026. Permanent successors for the head of CenterCBER and for Biologicsthe EvaluationFDA Commissioner have not yet been named. These and Researchother (CBER)changes atin the endFDA of April 2026, which createscreate uncertainty regarding the future leadership of the division that oversees the development of gene therapy products. In addition, changes to U.S. federal government policy since January 2025 have led to, in some cases, legal challenges and uncertainty around the funding, functioning and policy priorities of the U.S. federal regulatory agencies, including the FDA.

In October and November 2025, the U.S. federal government endured the longest government shutdown in U.S. history due to the failure of Congress to pass an appropriations budget for fiscal year 2026, and a subsequent partial government shutdown ensued in January and February of 2026. There can be no assurance that there will not be similar shutdowns of the federal government in the future. While there were some exemptions from these shutdowns with respect to certain aspects of the work carried out by the FDA, including essential safety oversight and ongoing reviews of certain existing applications where there was carryover funding, other work of the FDA during that time, such as acceptance of new applications, was suspended and the FDA workforce was reduced. These and similar events may impact the functioning of the FDA, including but not limited to subsequent government shutdowns or global health concerns, and could prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews or other regulatory activities, could significantly impact the ability of the FDA or other regulatory authorities to timely review and process our regulatory submissions, which could have a material adverse effect on our business. In addition, any future government shutdown could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

Our investigational biological products, if approved, could be considered reference products entitled to 12-year exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider a product candidate to be a reference productsproduct for competing products, potentially creating the opportunity for competition sooner than anticipated. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation. Moreover, the extent to which a biosimilar, once approved, will be substituted for any reference products in a way that is similar to traditional generic substitution for non-biological products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing.

In 2024, the FDA began accepting applications from sponsors for the START pilot program with the purpose of further accelerating the pace of development of novel drug and biological products that are intended to address an unmet medical need as a treatment for rare disease. The pilot is designed to be milestone-driven (i.e.i.e., to facilitate the progression of a development program to pivotal clinical study stage or the pre-BLA meeting stage) where product development programs selected would benefit from enhanced communication with the FDA. The START pilot program is intended to provide a mechanism for addressing clinical development issues that otherwise would delay or prevent a promising novel drug or biological product from progressing to the pivotal clinical trial stage or pre-BLA meeting stage. Participants in the START Pilot Program will receive enhanced communications with the FDA review staff. These enhanced communications will include at a minimum an initial meeting to review features of the pilot, discuss a pathway intended to support a marketing application, and to discuss specific issues for which a sponsor requests enhanced communications with the FDA. Additional communications will include ongoing interactions via email or teleconference that take place on a scheduled and/or as needed basis as agreed upon by the sponsor to discuss information on how best to facilitate more efficient development of potentially life-saving therapies for rare diseases and help sponsors generate high-quality, actionable data to support future new drug or biologics license applications. In June 2024, we announced that our product candidate NGN-401 had been accepted into the FDA’s START Pilot Program, which we expect will allow us to have access to more frequent advice from FDA staff to address product-specific development issues, possibly including clinical study design, choice of control group, patient population choices and other early development issues. As part of the START program, in June 2025 we announced written agreement from the FDA on key aspects of the registrational trial design for Embolden, our registrational clinical trial designed to evaluate NGN-401 gene therapy in patients with Rett syndrome. Despite the registrational trial and even though our product candidate NGN-401 for Rett syndrome has been accepted into the START Pilot Program, this may not result in a faster approval process for NGN-401 as a product candidate.

In addition, the FDA may designate a product candidate for Breakthrough Therapy designation if the product candidate is intended, alone or in combination with one or more other products, to treat a serious or life threatening disease or condition has preliminary clinical evidence which indicates that the product may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. The benefits of Breakthrough Therapy designation include eligibility for Priority Review, rolling submission of sections of the BLA and the FDA’s organizational commitment to help determine an efficient route to approval. In February 2026, the FDA granted Breakthrough Therapy designation to NGN-401 for the treatment of Rett syndrome following review of interim clinical data as of October 30, 2025. and weWe may also seek Breakthrough Therapy designation for one or more of our other product candidates in the future.

Participation in the START Pilot Program, RMAT designation, Breakthrough Therapy designation and the designation of a product for Fast Track review are within the discretion of the FDA. In addition, the START Pilot Program is still relatively new, having been established in 2024, so there is little historical information on how that program is expected to be administered, and the stated intentions of the program may not be met, or the program may cease to have appropriate funding due to changes in the regulatory landscape. Moreover, neither participation in the START Pilot Program nor the receipt of either Fast Track designation, Breakthrough Therapy designation or RMAT designation for a product candidate is any guarantee that there will be faster development or a faster or more streamlined regulatory review or approval process compared to products considered for approval under conventional FDA procedures. Neither participation in the START Pilot Program nor any of Fast Track designation, Breakthrough Therapy designdesignation or RMAT designation will assure ultimate approval by the FDA. In addition, the FDA may later decide that the product candidates no longer meet the conditions to qualify for those programs, and we may not receive the benefits of those programs for the relevant product candidate, or decide that the time period for FDA review or approval will not be shortened. Additionally, changes in the leadership of the FDA and other actions taken by the Trump Administration, including mass layoffs within the federal government, may impose constraints on the FDA’s ability to engage in activities in the normal course and may result in reductions to the FDA’s budget, employees and operations, which may lead to slower response times and longer review periods, potentially affecting our ability to take advantage of the benefits for the START program or any of the other designations granted to NGN-401, and progress development of our product candidates or obtain regulatory approval for our product candidates may be delayed.

As with the Fast Track, RMAT and Breakthrough Therapy designations and selection for participation in the START Pilot Program, the Priority Review designation is within the discretion of the FDA. Even if we believe that one or more of our product candidates meets the criteria for thisthese designations, the FDA may not agree and instead determine to not make such a designation. Even if one or more of our product candidates qualifies for thisthese designations, the FDA may later decide that such product candidate no longer meets the conditions for that designation, and we may not receive the benefits of the designation for that product candidate. If a product candidate is awarded Priority Review designation by the FDA, it may not result in a faster or more streamlined regulatory review or approval process compared to products considered for approval under conventional FDA procedures, and it does not assureensure ultimate marketing approval of such product candidate by the FDA.

We have received orphan drug designation from the FDA and orphan drug designation and advanced therapy medicinal product designation from the European Medicines Agency (“EMA”) for NGN-401 for the treatment of Rett syndrome. Although we may seek orphan product designation for some or all of our other product candidates, we may never receive such designations. Under the Orphan Drug Act, the FDA may designate a drug or biological product as an orphan drug if it is intended to treat a rare disease or condition, defined as a patient population of fewer than 200,000 in the United States, or a patient population greater than 200,000 in the United States where there is no reasonable expectation that the cost of developing the drug will be recovered from sales in the United States. Orphan drug designation must be requested before submitting a BLA. In the EU, the EMA’s Committee for Orphan Medicinal Products grants orphan drug designation to promote the development of products that are intended for the diagnosis, prevention, or treatment of a life-threatening or chronically debilitating condition affecting not more than five in 10,000 persons in the EU. Additionally, designation is granted for products intended for the diagnosis, prevention, or treatment of a life-threatening, seriously debilitating or serious and chronic condition when, without incentives, it is unlikely that sales of the drug in the EU would be sufficient to justify the necessary investment in developing the drug or biological product or where there is no satisfactory method of diagnosis, prevention, or treatment, or, if such a method exists, the medicine must be of significant benefit to those affected by the condition.

Under the Rare Pediatric Disease Priority Review Voucher program, upon the approval of a qualifying BLA for the treatment of a rare pediatric disease, the sponsor of such an application would be eligible for a rare pediatric disease priority review voucher that can be used to obtain priority review for a subsequent BLA or NDA. If aA product candidate that received Rare Pediatric Disease designation is eligible to receive a voucher if it is approved beforeby September 30, 2029. While we have obtained Rare Pediatric Disease designation for NGN-401 for the treatment of Rett syndrome, in order to obtain a priority review voucher, NGN-401 must be approved by September 30, 2029. If approval is not obtained by then, we would not be in a position to obtain a priority review voucher, unless Congress further reauthorizes the program beyond the current sunset date. Additionally, designation of a biological product for a rare pediatric disease does not guarantee that a BLA will meet the eligibility criteria for a rare pediatric disease priority review voucher at the time the application is approved. Finally, a Rare Pediatric Disease designation does not lead to faster development or regulatory review of the product or increase the likelihood that it will receive marketing approval.

In connection with the Reverse Merger, we declared a dividend,dividend to each person who, as of immediately prior to the effective time of the Reverse Merger, was a stockholder of the Company or had the right to receive our common stock pursuant to an existing pre-funded warrant, of the right to receive one non-transferable contingent value right (each, a “CVR”) for each then outstanding share of our common stock (before giving effect to a 1-for-4 reverse stock split (the “Reverse Stock Split”) that was implemented immediately prior to the effective time), each representing the non-transferable contractual right to receive certain contingent payments from the Company upon the occurrence of certain events within agreed time periods. Holders of options to purchase our common stock outstanding immediately prior to the effective time of the merger will also receive four CVRs for each share of our common stock that may be issued upon exercise of such option, such that they will receive the same number of CVRs as they would have received if the option had been exercised before the Reverse Stock Split, subject to certain conditions set forth in the CVR Agreement.

Pursuant to the terms of the CVR Agreement, the holders of our common stock prior to the effective time of the Reverse Merger, including holders of existing pre-funded warrants and holders of options to purchase our common stock outstanding immediately prior to the effective time of the merger and exercised after the effective time of the merger, rather than all of our current holders of our common stock, are the primary recipients of any net proceeds of the disposition of the legacy assets related to the business of Neoleukin Therapeutics, Inc. as it existed prior to the effective time of the Reverse Merger, the mitigation of legacy lease obligations related the business of Neoleukin Therapeutics, Inc. as it existed prior to the effective time of the Reverse Merger or receipt of any sales tax refund from the State of Washington based on tax returns we filed prior to the effective time of the Reverse Merger. While we have entered into agreements for the disposition of certain legacy assets of Neoleukin, we are still pursuing a resolution of the legacy lease obligations of Neoleukin and expect that we will need to allocate resources, including payment of certain up-front costs, and time from employees and management to complete the resolution of such obligations and to administer the provisions of the CVR Agreement (as defined below) and distribution of any payments to holders of the CVRs.

If our existing stockholders sell, or indicate an intention to sell, substantial amounts of our common stock in the public market, the trading price of our common stock could decline. Based on shares outstanding as of MarchJune 31,30, 2026, there are approximately 22,408,34522,623,063 shares of our common stock outstanding or issuable on exercise of pre-funded warrants to purchase common stock. After giving effect to the July 2026 Offering, that number increased to approximately 27,414,728. All outstanding shares of common stock and any shares issuable on exercise of pre-funded warrants or vested options to purchase our common stock, other than shares held by our affiliates or otherwise subject to restrictions on vesting and exercise, are freely tradable, without restriction, in the public market. If a significant number of these shares are sold, the trading price of our common stock could decline.

We have also filed a shelf registration statement covering the sale of up to $300.0 million of any combination of our common stock, preferred stock, debt securities, warrants or units, and may conduct one or more sales of securities pursuant to such registration statement from time to time. On July 2, 2026, we closed the July 2026 Offering pursuant to which we sold 4,124,999 shares of our common stock and prefunded warrants to purchase an additional 666,666 shares of our common stock. In August 2025, we entered into the Sales Agreement with Leerink, pursuant to which we have sold $31.0$37.1 million in shares of our common stock as of MarchJune 31,30, 2026 in “at the market” offerings. We may from time to time offer and sell through Leerink up to an additional $119.0$112.9 million of the common stock registered under the shelf registration statement pursuant to one or more additional “at the market” offerings. Sales of our common stock under the Sales Agreement with Leerink could be subject to business, economic or competitive uncertainties and contingencies, many of which may be beyond our control, and which could cause actual results from the sale of our common stock to differ materially from expectations.

We may be exposed to increased litigation from stockholders, suppliers and other third parties, which may have an adverse impact on our business and results of operations or may cause disruptions to our operations. In the past, stockholders have initiated class action lawsuits against biotechnology companies following periods of volatility in the market prices of these companies’ stock or immaterial changes to trial protocols, and we may also be subject to threats of litigation based on our recent merger activity.protocols. Such litigation, if instituted against us, could cause us to incur substantial costs and divert management’s attention and resources, which could have a material adverse effect on our business, financial condition and results of operations.

You should read the following discussion and analysis of our financial condition and results of operations in conjunction with the unaudited interim condensed consolidated financial statements and notes thereto included elsewhere in this report and our audited consolidated financial statements and notes thereto included as part of our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the SEC on March 24, 2026 (“Annual Report on Form 10-K”). Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report on Form 10-Q, including information with respect to our plans and strategy for our business, include forward-looking statements that involve risks, uncertainties, and assumptions. As a result of many factors, including those factors set forth in the section entitled “Risk Factors,” our actual results or outcomes, or the timing of our results or outcomes, could differ materially from the results or outcomes described in or implied by these forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those discussed in the section of this report entitled “Risk Factors.” You should carefully read the “Cautionary Note About Forward-Looking Statements” and “Risk Factors” sections of the Annual Report on Form 10-K as well as the risk factors included in Part II, Item 1A of this Quarterly Report on Form 10-Q to gain an understanding of the important factors that could cause actual results to differ materially from the results described below.

Our firstlead clinical-stage program, NGN-401, is in development for the treatment of Rett syndrome, a severe and progressive neurodevelopmental disease with substantial neurological and physical impairments and significant unmet need. NGN-401 is purposefully designed to utilize the EXACT platform and adeno-associated virus (“AAV”) delivery via intracerebroventricular (“ICV”) administration, and to deliver the full-length MECP2 gene which preserves the complete set of endogenous regulatory elements to restore functional MeCP2 protein. OurWe believe ICV delivery is the most suitable route of administration to achieve optimal biodistribution in key regions of the brain and other parts of the nervous system that underlie Rett syndrome pathophysiology. We have completed dosing of 25 participants in our ongoing registrational trial of NGN-401, EmboldenTM, is a single-arm, open-label, baseline-controlled trial evaluating the 1E15 vg dose of NGN-401 gene therapy in females with Rett syndrome. The Embolden trial is designed to evaluate NGN-401 in females ages three and above with potential to support a broad label in a single study and enable an efficient path to market. ApproximatelyTop-line 90% of participants have been dosed in Embolden, and weresults are on track to complete dosingexpected in the second quarterhalf of 2026. We completed dosing in a Phase 1/2 open-label, multi-center clinical trial of NGN-401 gene therapy for Rett syndrome, with ten participants receiving the 1E15 vg dose. NGN-401 is delivered using a one-time ICV procedure, which we believe is the most suitable route of administration to achieve optimal biodistribution in key regions of the brain and other parts of the nervous system that underlie Rett syndrome pathophysiology. Clinical grade NGN-401 manufactured at our fully operational current good manufacturing practices (“cGMP”) facility in Houston, Texas was used for dosing in the Phase 1/2 clinical trial and is being used for the Embolden trial. We believe that our in-house manufacturing capabilities better enable control of product quality and development timelines, strategic pipeline and financial flexibility, and clinical-to-commercial continuity.2027.

We received clearance of our Investigational New Drug (“IND”) application by the U.S. Food and Drug Administration (“FDA”) in January 2023. We completed enrollmentdosing in the Phase 1/2 open-label, multi-center clinical trial evaluating NGN-401 for the treatment of female patients with classic Rett syndrome in the second quarter of 2025. The trial is assessing the safety, tolerability, and efficacy of NGN-401 at a dose of 1E15 vg in eight participants in an ages 4-10 years cohort and two participants in an ages 11 years and older cohort.

Based on research we conducted in 2025 related to hyperinflammatory syndromes and AAV gene therapy, HLH has only been reported following doses of AAV that are generally in the 1E14 vg/kg range or higher. The 1E15 vg dose used in the Phase 1/2 trial and in the Embolden registrational trial translates into the E13 vg/kg range, and we are not aware of any case of HLH ever being reported at this dose. HLH is an acute inflammatory reaction that, if it were to occur, would be expected to happen within days after dosing. Out of an abundance of caution, we incorporated enhanced monitoring into our Phase 1/2 and Embolden protocols for HLH markers, including ferritin, and a treatment algorithm thatthat, when administered early, has been used successfully to treat cases of HLH both in other AAV gene therapies and other known causes of HLH.

In June 2025, we first announced written agreement from the FDA on key elements of the NGN-401 Embolden registrational trial design, and we confirmed these elements and the trial design in September 2025. The primary endpoint is a responder-based composite endpoint that will assess an improvement in the Clinical Global Impression–Improvement Scale (“CGI-I”) with Rett syndrome anchors and the gain of a developmental milestone, compared to the participant’s own baseline. Responders are defined as participants who attain a CGI-I score less than or equal to three (“minimally improved”) and gain any one developmental milestone from a list of 28, as captured through standardized video recordings and independently verified by blinded central raters at the 12-month endpoint. The primary analysis to support the planned BLA is expected to occur after the first 24 participants have completed 12 months of follow-up. A response rate of 35%33% is the minimum threshold for success to reject the null hypothesis in the Embolden trial. We expect to report top-line data in the second half of 2027, and therefore we do not plan to share data updates from the trial before that time.

We previously reached alignment with the FDA on our potency assay strategy and chemistry, manufacturing and controlcontrols (“CMC”) planning for the program. We plan to initiateinitiated our Process Performance Qualification (“PPQ”) campaign in mid-2026July 2026 and confirmed our commercial manufacturing scale is the same as our current clinical manufacturing scale, removing the need for comparability studies. We expect to complete the PPQ runs by the end of 2026.

Since our inception, we have funded our operations primarily with outside capital (e.g., proceeds from the sale of preferred stock, common stock and pre-funded warrants) and have raised aggregate net proceeds of approximately $552.1$692.8 million.million, including net proceeds of approximately $134.8 million from the July 2, 2026 public offering. See “Liquidity and Capital Resources” for additional information. However, we have incurred significant recurring losses, including a net loss of $30.9$65.4 million and $22.6$44.7 million for the threesix months ended MarchJune 31,30, 2026 and 2025, respectively. In addition, as of MarchJune 31,30, 2026, we had an accumulated deficit of $383.6$418.1 million and cash, cash equivalents and short-term investments totaling $243.2$225.4 million. InFollowing orderthe tocompletion continueof our operations,July 2, 2026 public offering, we mustbelieve achieveour profitableexisting operationscash, cash equivalents and/or obtaininvestments additionalwill equitybe or debt financing. Until we achieve profitability, management planssufficient to fund our operations andinto the first quarter of 2029. We may seek additional capital expenditures with cash on hand andin the salefuture andto issuanceadvance ofour securities.pipeline, support our operations or pursue strategic opportunities. There can be no assurance that we will be successful in raising additional capital or that such capital, if available, will be on terms that are acceptable to us. If we are unable to raise sufficient additional capital, we may be compelled to consider actions such as reducing the scope of our operations and planned capital expenditures or selling certain assets, including intellectual property assets.

Research and development activities are central to our business model. Product candidates in later stages of clinical development generally have higher development costs than those in earlier stages of clinical development, primarily due to the increased size and duration of later-stage clinical trials. We expect our research and development expenses to increaseremain significantlysignificant over the next several years as we increasecontinue personnelpatient costs,monitoring includingactivities stock-basedfor compensation,our ongoing registrational trial, conduct clinical trials, including later-stage clinical trials for current and future product candidates, complete process performance qualification (PPQ) activities, and prepare regulatory filings for our product candidates.

Comparison of the Three and Six Months Ended MarchJune 31,30, 2026 and 2025

Research and development expenses were $25.2$25.5 million for the three months ended MarchJune 31,30, 2026, as compared to $17.8$19.4 million for the three months ended MarchJune 31,30, 2025.

Expenses related to the Rett syndrome program increased primarily due to a $5.1$2.9 million increase in clinical trial costs related to the Phaseongoing 1/2 and pivotalregistrational clinical trial offor NGN-401,NGN-401 and a $2.4$0.7 million increase in chemistry, manufacturing and controls (“CMC”) costs primarily related to CDMO support and PPQ runs for NGN-401NGN-401, andpartially offset by a $1.0$0.6 million decrease in preclinical costs. The decrease in expenses related to the Batten disease program was primarily driven by a $0.6$0.3 million decrease in clinical trial costs for the Phase 1/2 clinical trial of NGN-101, due to the de-prioritization of the program. The decrease in expenses related to the Early Discovery program was driven by a $0.6 million decrease in preclinical costs primarily due to lower costs of preclinical development for the Early Discovery program.

General and administrative expenses were $8.2$11.2 million for the three months ended MarchJune 31,30, 2026, as compared to $8.2$6.7 million for the three months ended MarchJune 31,30, 2025. GeneralThe andincrease administrative expenses were comparable to prior year, with increaseswas primarily attributable to: (i) a $3.3 million increase in stock-based compensation expense, driven by an increase in headcount as well as by an increase of approximately $2.7 million related to PSU expense as the second underlying performance condition was deemed probable of achievement and currently considered probable to vest, (ii) a $0.6 million increase in personnel-related expenses, reflecting higher headcount to support business operations, (iii) a $0.4 million increase in other expenses, primarily related to higher corporate costs and pre-commercial activities, and (iiiv) a $0.1 million increase in personnel-related expenses, reflecting higher headcount to support business operations, and (iii) a $0.1$0.3 million increase in professional and consultant fees,fees. primarilyThe dueincrease to higher patent and IT services costs. These increases werewas partially offset by a $0.6$0.1 million decrease in stock-based compensationoffice-related expense.

Interest income decreased by $0.9 million for the three months ended MarchJune 31,30, 2026, as compared to the three months ended MarchJune 31,30, 2025. The decrease was primarily due to a decrease in short-term investments and lower yields on cash, cash equivalents, and short-term investment balances.

The change in other expenses was not material for the three and six months ended MarchJune 31,30, 2026 as compared to the three and six months ended MarchJune 31,30, 2025.2025 respectively.

As of MarchJune 31,30, 2026, we had cash, cash equivalents and short-term investments totaling $243.2$225.4 million. Since inception and through the issuance of these financial statements,inception, we have funded our operations primarily throughwith outside capital (e.g., proceeds from the salessale of convertiblepreferred preferredstock, common stock and commonpre-funded stockwarrants) forand have raised aggregate net proceeds of approximately $552.1$692.8 million, including net proceeds of approximately $134.8 million from salethe ofJuly common2, stock2026, pursuantpublic tooffering ourdescribed ATM Sales Agreement.below.

For the threesix months ended MarchJune 31,30, 2026, we used $26.1$49.9 million of cash in operating activities. Cash used in operating activities reflected our net loss of $30.9$65.4 million, a $1.2$3.4 million decrease in our net operating assets and non-cash charges of $3.6$12.2 million, which consisted primarily of $3.6$11.5 million of stock-based compensation, $0.8$1.7 million in depreciation and impairment expense and $0.2$0.4 million in non-cash operating lease expense partially offset by $0.4$0.7 million in accretion on the held-to-maturity investments and $0.7 million change in the contingent value rights liability. The primary use of cash was to fund our operations related to the development of our product candidates.

For the threesix months ended MarchJune 31,30, 2025, we used $20.8$40.2 million of cash in operating activities. Cash used in operating activities reflected our net loss of $22.6$44.7 million, a $1.4$1.8 million net increase in our operating assets and liabilities, and non-cash charges of $3.3$6.2 million, which consisted primarily of $4.0$7.5 million in stock-based compensation, $0.7$1.5 million in depreciation and $0.2$0.4 million in non-cash operating lease expense, partially offset by $1.7$3.2 million in accretion on the held-to-maturity investments. The primary use of cash was to fund our operations related to the development of our product candidates.

For the threesix months ended MarchJune 31,30, 2026, net cash flows provided by investing activities consisted of proceeds from maturities of short-term investments of $130.0$249.1 million, partially offset by purchases of short-term investments of $83.5$196.2 million and purchases of property and equipment of $0.3$0.6 million.

For the threesix months ended MarchJune 31,30, 2025, net cash flows used in investing activities consisted of purchases of short-term investments of $89.0$149.4 million and purchases of property and equipment of $0.8$0.9 million, partially offset by proceeds from maturities of short-term investments of $44.7$112.7 million.

For the threesix months ended MarchJune 31,30, 2025, net cash flows provided by financing activities were insignificant.

We lease approximately 33,300 square feet of office space in Seattle, WashingtonWashington, that was previously used by Neoleukin for offices, a laboratory for research and development, and related uses. The lease expires on February 1, 2029, with the option to extend the lease for two additional five-year terms. The renewal periods were not included in the lease term for purposes of determining the lease liability.

Each contingent value right (“CVR”) distributed pursuant to the CVR Licensing Agreement, dated December 18, 2023, by and between us and the rights agent (the “CVR Agreement”) contains the contractual right to receive certain net savings, if any, realized by June 30, 2029 in connection with certain legacy lease obligations related to our business prior to the reverse merger with Neoleukin (the “Lease CVR”). As of MarchJune 31,30, 2026, approximately $0.4 million was recorded as a component of the contingent value rights liability arising from the Lease CVR on our condensed consolidated balance sheet. The commitment relates to Neoleukin’s sublease agreement, effective October 31, 2023, for one of its properties with an unrelated third party for the remainder of the lease term. For more information on the Lease CVR, see Note 9, Commitments and Contingencies—Lease CVR, in the notes to the financial statements included in Part I, Item 1 of this Quarterly Report on Form 10-Q.

The December 2023 CVR Licensing Agreement and April 2024 CVR Licensing Agreement collectively account for the total Intellectual Property CVR. As of MarchJune 31,30, 2026, no other development and sales milestones were achieved nor deemed probable of achievement under the December 2023 CVR Licensing Agreement. For more information on the Intellectual Property CVR, see Note 9, Commitments and Contingencies—Intellectual Property CVR, in the notes to the financial statements included in Part I, Item 1 of this Quarterly Report on Form 10-Q.

The following table summarizes the components of the contingent value rights liability as of MarchJune 31,30, 2026 and December 31, 2025 (in thousands):

In December 2020, we entered into a Master Collaboration Agreement (the “MCA”) with the University Court of the University of Edinburgh (the “University of Edinburgh”). Under the MCA, we and the University of Edinburgh agreed to collaborate on certain research and development projects (“Projects”), and we agreed to provide funding for such Projects for a 40-month initial term, which was extended in November 2023 for an additional 33 months and may be further extended by mutual agreement. Under the MCA, we are obligated to pay semi-annual installment payments relating to funding of costs for personnel and lab consumables for the duration of the MCA. Either party may terminate the MCA for convenience upon 90 days’ notice. If we were to terminate the MCA, we would be responsible for all non-cancellable costs and commitments related to any particular Project and any and all funding costs for any person working on such Project.

In January 2023, we entered into a Non-Exclusive License Agreement with Sigma-Aldrich Co. LLC, pursuant to which we have a license to certain patents and know-how on a non-exclusive basis related to certain cell lines used in our baculovirus process in exchange for a small annual fee on a product-by-product basis, payable once the first product candidate entersentered the clinic. In addition, on a product-by-product basis, we are obligated to pay up to $2.5 million in the aggregate for development-related milestones. This agreement remains in force for as long as we continue to possess and use the licensed technology. We may terminate this agreement for convenience upon 60 days’ notice.

Our financial statements are prepared in accordance with U.S. GAAP. The preparation of the financial statements and related disclosures requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, costs and expenses, and the disclosure of contingent assets and liabilities in our financial statements. We base our estimates on historical experience, known trends and events and various other factors that management believes are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Management evaluates estimates and assumptions on a periodic basis. Our actual results may differ from these estimates. A summary of our significant accounting policies is presented in Part II, Item 8 of our Annual Report on Form 10-K for the year ended December 31, 2025. There have been no material changes to our significant accounting policies during the threesix months ended MarchJune 31,30, 2026.