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

Since inception, we have incurred significant net losses. Our net losses were $124.7$174.3 million and $96.0$124.7 million for the years ended December 31, 20242025 and 2023,2024, respectively. As of December 31, 2024,2025, we had an accumulated deficit of $783.5$957.8 million. Prior to our acquisition of AavantiBio, Inc.,Inc. orin December 2022 (the Acquisition,“Acquisition”) we devoted substantially all of our efforts to research and development, including clinical development of SGT-001, which we are no longer developing, and preclinical development of SGT-003, as well as to building out our management team and infrastructure. Following the Acquisition, we alsohave begandevoted devotingour efforts to preclinicalthe research and development of our other Candidates, including clinical development of SGT-003,SGT‑003, SGT‑212 and SGT-501, as well as building out our management team. We expect that it could be several years before we have a commercialized product, and we may never have a commercialized product. We expect to continue to incur significant expenses and see continued operating losses for the foreseeable future. We anticipate that our expenses will increase substantially if, and as, we:

continue to enroll patientsparticipants in our INSPIRE DUCHENNEDUCHENNE, trialIMPACT DUCHENNE, FALCON and ARTEMIS trials and advance clinical development of SGT-003SGT-003, SGT-212 and SGT-501;

advance our other Candidates into clinical trials, including our planned Phase 1b clinical trial of SGT-212 in adult patients with FAtrials;

We may never achieve or maintain profitability. To become and remain profitable, we must develop and eventually commercialize one or more Candidates with significant market potential. This will require us to be successful in a range of challenging activities, and our expenses will increase substantially as we continue to enroll patientsparticipants in and conduct the INSPIRE DUCHENNEDUCHENNE, trial,IMPACT initiateDUCHENNE, enrollmentFALCON inand ourARTEMIS planned Phase 1b clinical trial of SGT-212,trials and continue to develop our pipeline and complete ongoing and planned preclinical studies and clinical trials of our Candidates, obtain marketing approval for our Candidates, develop adjacent technologies such as assays, develop and validate commercial-scale manufacturing processes, manufacture, market and sell any future Candidates for which we may obtain marketing approval and satisfy any post-marketing requirements. Moreover, the manufacturing process requires materials which may fluctuate in cost or be limited or unavailable to us, as well as relationships with contract development and manufacturing organizations (“CDMOs”) to facilitate the manufacturing process. We may never succeed in any of these activities and, even if we do, we may never generate revenue that is significant or large enough to achieve profitability. If we do achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would decrease the value of our company and could impair our ability to raise capital, maintain our research and development efforts, expand our business or continue our operations. A decline in the value of our company also could cause stockholders to lose all or part of their investment.

We expect our expenses to increase in connection with our ongoing activities, particularly as we continue the research and development of, conduct clinical trials of, and seek marketing approval for our Candidates. In addition, if we obtain marketing approval for our Candidates, we expect to incur significant expenses related to product sales, marketing, manufacturing and distribution. We also expect to continue to incur additional costs associated with operating as a public company. While we believe that our cash, cash equivalents and available-for-sale securities as of December 31, 2024,2025, together with the net proceeds from our underwrittenprivate offeringplacement that closed onin FebruaryMarch 19, 2025,2026, will be sufficient to fund our operating expenses and capital requirements into the first half of 2027,2028, we have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently anticipate. In order to continue to operate our business beyond that time, we will need to raise additional funds. However, there can be no assurance that we will be able to generate funds on terms acceptable to us, on a timely basis, or at all. In addition, we anticipate that we will need additional funding to complete the development of our Candidates.

the progress, costs and results of the INSPIRE DUCHENNEDUCHENNE, trial,IMPACT ourDUCHENNE, plannedFALCON Phaseand 1bARTEMIS clinical trial of SGT-212trials and any future clinical trials of our Candidates;

Identifying potential candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to submit a Biologics License Application (“BLA”) or obtain marketing approval and achieve product sales. In addition, our Candidates, if approved, may not achieve commercial success. Our product revenue, if any, will be derived from or based on sales of our Candidates that may not be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all, and may be impacted by the economic climate and market conditions. Our ability to raise additional funds may be adversely impacted by general economic conditions, both inside and outside the U.S., including disruptions to, and instability and volatility in, the credit and financial markets in the U.S. and worldwide, heightened inflation, interest rate and currency rate fluctuations, global trade programs, tariffs and economic slowdown or recession as well as concerns related to public health emergencies or pandemics and geopolitical events, including civil or political unrest. In addition, market instability and volatility, high levels of inflation and interest rate fluctuations may increase our cost of financing or restrict our access to potential sources of future liquidity. Alternatively, we may seek additional capital due to favorable market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans.

maintaining and enhancing a commercially viable, sustainable, scalable, reproducible and transferable manufacturing processesprocess for our Candidates that is compliant with cGMPs;

Our operations to date have been limited to organizing and staffing our company, business planning, raising capital, acquiring rights to our technology, conducting research and development activities, establishing research and development collaborations, identifying and acquiring Candidates, establishing manufacturing arrangements andarrangements, undertaking preclinical studies and clinical trials.trials, and licensing of our POLARIS-101TM capsid. As a company, we have limited experience in clinical development. We have not yet demonstrated the ability to complete clinical trials of any Candidate, obtain marketing approvals, manufacture at commercial-scale or conduct sales and marketing activities necessary for successful commercialization. Consequently, any predictions our stockholders make about our prospects may not be as accurate as they could be if we had a longer operating history or prior experience integrating acquired businesses into our existing business.

Our results of operations could be harmed by general conditions in the global economy and in the global financial markets. A severe or prolonged economic downturn, including the impact of increased interest rates and inflationinflation, (suchand asglobal thetrade recentprograms riseand in inflation in the United States),tariffs, could result in a variety of risks to our business, including weakened demand for our Candidates and our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could strain our manufacturers, possibly resulting in manufacturing disruption, or cause delays in payments for our services by third-party payors or our future collaborators. Any of the foregoing could harm our business and we cannot anticipate all of the ways in which the current economic climate and financial market conditions could harm our business.

We hold a portion of our cash and cash equivalents that we use to meet our working capital and operating expense needs in deposit accounts at multiple financial institutions. The balance held in these accounts may exceed the Federal Deposit Insurance Corporation,Corporation or FDIC,(“FDIC”) standard deposit insurance limit of $250,000. If a financial institution in which we hold such funds fails or is subject to significant adverse conditions in the financial or credit markets, we could be subject to a risk of loss of all or a portion of such uninsured funds or be subject to a delay in accessing all or a portion of such uninsured funds. Any such loss or lack of access to these funds could adversely impact our short-term liquidity and ability to meet our operating expense obligations, including payroll obligations.

For example, on March 10, 2023, Silicon Valley Bank,Bank or SVB,(“SVB”) and Signature Bank, were closed by state regulators and the FDIC was appointed receiver for each bank. The FDIC created successor bridge banks and all deposits of SVB and Signature Bank were transferred to the bridge banks under a systemic risk exception approved by the United States Department of the Treasury, the Federal Reserve and the FDIC. If financial institutions in which we hold funds for working capital and operating expenses were to fail, we cannot provide any assurances that such governmental agencies would take action to protect our uninsured deposits or investments in a similar manner.

Our pipeline of gene transfer Candidates utilize novel technology, which makes it difficult to predict the time and cost of development and of subsequently obtaining regulatory approval. To our knowledge, only a limited number of gene transfer products have been approved for commercialization in the United States and the European Union.

Our future success depends on our successful development of our Candidates. Our risk of failure is high. We havehad experienced problems and delays in developing SGT-001, which we are no longer developing, and may in the future experience problems or delays in developing our Candidates. Any such problems or delays would cause unanticipated costs, and any development problems may not be solved. For example, we or another party may uncover a previously unknown risk associated with our Candidates, the adeno-associated virus, or AAV,AAV capsid, construct or other issues resulting in toxicity or lack of efficacy that may be more problematic than we currently believe and this may prolong the period of observation required for obtaining, or result in the failure to obtain, regulatory approval or may necessitate additional clinical testing.

If we are unable to obtain all necessary animals and other supplies required for the conduct of our preclinical testing and studies, or the animal models do not perform as expected, we may be unable to complete such preclinical development testing and studies in a timely manner or at all. For example, some of our IND-enabling toxicology and other studies require certain non-human primates, or NHPs,NHPs that may be imported from countries in which trade relation with the U.S. are or may become challenging or through vendors who may not be able to timely source certain NHPs or at all, which may impair our ability to complete preclinical development testing and studies to support IND or similar applications or delay submission of such applications. Additionally, we may fail to demonstrate adequate Candidate efficacy and/or safety as required by regulatory authorities. We may fail to access relevant, adequate, or necessary animal models, including genetic models of disease and non-human primates in particular, for use in such studies as requested by regulatory authorities. We may also experience substantial delays as a result of our reliance on contract research organizations (“CROs”) to conduct all animal model experimentation necessary to assess the efficacy and safety of our Candidates. Any of these factors may result in delays to Candidate progression, inability to obtain regulatory approval, and/or substantial increases in Candidate development costs.

In addition, the product specifications and the clinical trial requirements of the FDA, the European Commission, the European Medicines Agency (the “EMA”) and other regulatory authorities and the criteria these regulators use to determine the safety and efficacy of a product candidate vary substantially according to the type, complexity, novelty and intended use and market of such product candidate. The regulatory approval process for novel product candidates such as ours is unclear and can be more expensive and take longer than for other, better known or more extensively studied product candidates. To our knowledge, only a limited number of gene transfer products have been approved for commercialization in the United States and the European Union. As a result, it is difficult to determine how long it will take or how much it will cost to obtain regulatory approvals for our gene transfer Candidates in either the United States or the European Union, if at all. Approvals by the European Commission may not be indicative of what the FDA may require for approval and vice versa.

Our gene transfer Candidates may cause undesirable side effects or have other properties that could delay or prevent their clinical development, regulatory approval, limit their commercial potential or result in significant negative consequences following any potential marketing approval.

In the second quarter of 2024, patient dosing commenced in our INSPIRE DUCHENNE trial. Our other current Candidates have not yet been studied in human patients. During the conduct of clinical trials, patientsparticipants may experience changes in their health, including illnesses, injuries, discomforts or a fatal outcome. Often, it is not possible to determine whether the Candidate being studied caused these conditions. For instance, we reported a serious adverse event in IGNITE DMD, which resulted in a clinical hold in November 2019, which has since been resolved. In April 2021, a patientparticipant treated with SGT-001 in IGNITE DMD experienced a systemic inflammatory response classified as a serious adverse event and considered by the investigator to be drug related. In addition, there has been one treatment-related serious adverse event reported in the INSPIRE DUCHENNE trial, identified as a Grade 3 immune-mediated myositis.

There have been several significant adverse side effects in gene therapy treatments in the past, including reported cases of leukemia and death seen in other clinical trials. The FDA convened the Cellular, Tissue, and Gene Therapies Advisory Committee in September 2021 to discuss toxicity risks of AAV based gene therapy products and discussed risks including oncogenicity risks due to capsid genome integration, hepatotoxicity, thrombotic microangiopathy, and neurotoxicity (especially related to dorsal root ganglion toxicity). While new recombinant capsids have been developed with the intent to reduce these side effects, gene therapy is still a relatively new approach to disease treatment and additional adverse side effects could develop. There have been reports of significant adverse side effects, including muscle weaknessweakness, myocarditis, and myocarditis,acute liver injury, in clinical trials of other gene therapy treatments for Duchenne that may be related to the type and location of the specific gene mutation causing the disease. OneIn clinicalanother trialgene sponsortherapy reportedtreatment, athere death,have precededbeen by hypovolemia and cardiogenic shock,reports of aAAV mediated acute liver failure leading to death in non-ambulatory Duchenne subjectboys with advancedDuchenne diseasein andthe cardiacsetting dysfunction.of commercially available product. There also is the potential risk of delayed adverse events following exposure to gene therapy products due to persistent biologic activity of the genetic material or other components of products used to carry the genetic material. Possible adverse side effects that may occur with treatment with gene therapy products include an immunologic reaction early after administration that could substantially limit the effectiveness of the treatment or represent safety risks for patients. Additionally, in previous clinical trials involving AAV capsids for gene therapy, some subjects experienced the development of a positive ELISPOT test associated with T‑cell responses, which is of unclear clinical translatability. If T-cells are activated, the cellular immune response system may trigger the removal of transduced cells. If our gene transfer Candidates demonstrate a similar effect or other undesirable side effects, we may decide or be required to halt or delay further clinical development of our Candidates involving AAV capsids for gene therapy.

Adverse side effects may be observed following administration of any AAV gene therapy, including SGT-003 or other Candidates. Not all contemplated AAV delivery systems have been validated in human clinical trials previously, such as AAV‑SLB101,POLARIS-101TM, which is a novel capsid. If a delivery system does not meet the safety criteria or cannot provide the desired efficacy results, then we may be forced to suspend or terminate our development of SGT-003 or other Candidates. If certain adverse side effects were to occur in the future and we are unable to demonstrate that they were not caused by the administration process or related procedures, the FDA, the European Commission, the EMA or other regulatory authorities could order us to cease further development of, or deny approval of, SGT-003 or other Candidates for any or all targeted indications. Even if we are able to demonstrate that any serious adverse events are not product-related, such occurrences could affect patientparticipant recruitment or the ability of enrolled patientsparticipants to complete the clinical trial. PatientsParticipants will also create antibodies to the AAV capsid and a second administration of gene transfer might not be safe or successful.

Additionally, if one or more of our Candidates receive marketing approval, the FDA could require us to adopt a Risk Evaluation and Mitigation Strategy,Strategy or REMS,(“REMS”) to ensure that the benefits outweigh the risks, which may include, among other things, a medication guide outlining the risks of the product for distribution to patients and a communication plan to health care practitioners. Furthermore, if we or others later identify undesirable side effects caused by our Candidates, several potentially significant negative consequences could result, including:

In November 2019, the FDA placed a clinical hold on our clinical trial of SGT-001 following a serious adverse event in IGNITE DMD. The third patientparticipant in the 2E14 vg/kg cohort of IGNITE DMD, dosed in late October 2019, experienced a serious adverse event deemed related to the study drug that was characterized by complement activation, thrombocytopenia, decrease in red blood cell count, acute kidney injury, and cardio-pulmonary insufficiency. In April 2021, an eighth patientparticipant was treated with SGT-001. The patientparticipant experienced a systemic inflammatory response which has since fully resolved. The event was classified as a serious adverse event and considered by the investigator to be drug related. While SGT-003 utilizes POLARIS-101TM , a different capsid than SGT-001was utilized in SGT-001, and includes other changes to the construct and manufacturing process to help avoid or mitigate any such events, we cannot guarantee that similar serious adverse events or clinical holds will not happen in ongoing and future clinical trials of SGT-003. We also cannot guarantee that similar serious adverse events or clinical holds will not happen in planned and future clinical trials of any of our other Candidates.

We have never completed a clinical trial and may be unable to do so for any Candidate, including SGT-003SGT-003, SGT-212, SGT-501 and other Candidates.

We are early in our development efforts and we have never completed a clinical trial. InWe theare second quarter of 2024, patient dosing commenced inconducting our INSPIRE DUCHENNE trial.trial Weof anticipateSGT-003, initiatingour aIMPACT PhaseDUCHENNE 1btrial clinicalof SGT-003, our FALCON trial of SGT-212 inand adultsour withARTEMIS FA in the second halftrial of 2025.SGT-501. Our other current Candidates are still in the preclinical and discovery stages of development. Preclinical studies involve a lengthy and expensive process with an uncertain outcome. There are many potential preclinical models to test for different disease states, and we could fail to choose the best or a predictive preclinical model to determine proof of concept and potential safety and efficacy of our Candidates. We may decide to suspend further testing on our Candidates or technologies if, in the judgment of our management and advisors, the preclinical test results do not support further development.

We will need to successfully initiate our planned clinical trials and complete our ongoing clinical trials in order to obtain FDA approval to market SGT-003, SGT-212SGT-212, SGT-501 and other Candidates. We have limited experience in preparing, submitting and prosecuting regulatory submissions, and have not previously submitted a BLA for any Candidate. We cannot be sure that submission of an IND will result in the FDA allowing clinical trials to begin or to begin as proposed, or that, once begun, issues will not arise that suspend or terminate such clinical trials. Carrying out later-stage clinical trials and the submission of a successful BLA is a complicated process. This may be particularly true for design of a pivotal trial for the treatment of Duchenne as the FDA has not given clear guidance as to the necessary endpoints for approval of a treatment for Duchenne. In addition, we cannot be certain how many clinical trials of SGT-003, SGT-212SGT-212, SGT-501 or other Candidates will be required or how such trials should be designed. Consequently, we may be unable to successfully and efficiently execute and complete necessary clinical trials in a way that leads to BLA submission and approval of SGT-003, SGT-212SGT-212, SGT-501 or other Candidates. We may require more time and incur greater costs than our competitors and may not succeed in obtaining regulatory approvals of Candidates that we develop. Failure to commence or complete, or delays in, clinical trials,trials could prevent us from or delay us in commercializing SGT-003, SGT-212SGT-212, SGT-501 and other Candidates.

From time to time, we may announce or publish preliminary or interim data from clinical trials. Positive preliminary or interim data may not be predictive of such trial’s subsequent or overall results. Preliminary or interim data are subject to the risk that one or more of the outcomes may materially change as more data becomes available. Additionally, preliminary or interim data are subject to the risk that one or more of the biologic or clinical outcomes may materially change as patientparticipant enrollment continues and more patientparticipant data becomes available. Therefore, positive preliminary or interim data in any ongoing clinical trial, including the INSPIRE DUCHENNE trial, may not be predictive of such results in the completed trial. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully evaluate all data. As a result, preliminary or interim data that we report may differ from future results from the clinical trials, or different conclusions or considerations may qualify such results,results once additional data have been received and fully evaluated. Preliminary or interim data also remain subject to audit and verification procedures that may result in the final data being materially different from the preliminary or interim data we previously published. As a result, preliminary or interim data should be viewed with caution until the final data are available. Material adverse changes in the final data compared to preliminary or interim data could significantly harm our business prospects.

delays in enrolling patientsparticipants in clinical trials;

delays in recruiting suitable subjects to participate in our clinical trials, including because such trials have restrictive eligibility criteria or may be placebo-controlled trials and patientsparticipants are not guaranteed to receive treatment with our Candidates, or as a result of alternative therapies or competing trials;

failure to perform in accordance with FDA good clinical practices,practices or GCPs,(“GCPs”) or applicable regulatory guidelines in the European Union and other countries;

be sued and held liable for harm caused to patientsparticipants; or experience damage to our reputation.

We do not have the personnel capacity to conduct or manage the clinical trials that will be necessary for the development of our Candidates. ForWe are relying on third parties to manage, monitor and conduct our INSPIRE DUCHENNEDUCHENNE, trialIMPACT weDUCHENNE, are relying,FALCON and forARTEMIS any plannedtrials and future clinical trials we expect we will relyrely, on third parties to assist us in managing, monitoring and conducting ourany planned or future clinical trials. If these third parties fail to comply with applicable regulations or do not adequately fulfill their obligations under the terms of our agreements with them, we may not be able to enter into alternative arrangements without undue delay or additional expenditures and, therefore, clinical trials for SGT-003SGT-003, SGT-212, SGT-501 or other Candidates may be delayed or unsuccessful.

We may find it difficult to enroll patientsparticipants in our clinical trials, which could delay or prevent us from proceeding with clinical trials of SGT-003, SGT-212SGT-212, SGT-501 or our other Candidates.

Identifying and qualifying patientsparticipants to participate in any clinical trials of SGT-003, SGT-212SGT-212, SGT-501 and our other Candidates are critical to our success. Because of our primary focus on rare diseases, we may have difficulty enrolling a sufficient number of eligible patients.participants. The timing of any clinical trials depends on our ability to recruit patientsparticipants to participate as well as complete required follow-up periods. If patientsparticipants are unwilling or unable to participate in our gene therapy clinical trials, including because of negative publicity from adverse events related to our Candidates, other approved therapies, or due to competitive clinical trials or approvals for similar patientparticipant populations, clinical trials in products employing our capsid or our platform or for other reasons, the timeline for recruiting patients,participants, conducting clinical trials and obtaining regulatory approval of SGT-003, SGT-212SGT-212, SGT-501 or other Candidates may be delayed. We may also experience delays if patientsparticipants withdraw from the clinical trial or do not complete the required monitoring period. Furthermore, we may face difficulties in recruiting patientsparticipants to enroll in, or once enrolled, retaining patientsparticipants in future clinical trials if they or their caretakers are affected by public health emergencies or pandemics or are fearful of traveling to, or are unable to travel to, our clinical trial sites because of public health emergencies or pandemics or other unforeseen events. These delays could result in increased costs, delays in advancing SGT-003SGT-003, SGT-212, SGT-501 or other Candidates, delays in testing the effectiveness of our Candidates or termination of clinical trials altogether.

We may not be able to identify, recruit and enroll a sufficient number of patients,participants, or those with required or desired characteristics, to complete any clinical trials in a timely manner. PatientParticipant enrollment and trial completion is affected by many factors, including:

size of the patientparticipant population and the process for identifying subjects;

ability to monitor subjects adequately during and after treatment; and in the case of pivotal trials, the risk that patientsparticipants may opt not to enroll because they are not assured treatment with our Candidate.

If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials, our development plans may be impacted. For example, in December 2022, with the passage of FDORA,the Food and Drug Omnibus Reform Act (“FDORA”), Congress required sponsors to develop and submit a diversity action plan for each Phase 3 clinical trial or any other “pivotal study” of a new drug or biological product. These plans are meant to encourage the enrollment of more diverse patientparticipant populations in late-stage clinical trials of FDA-regulated products. In June 2024, as mandated by FDORA, the FDA issued draft guidance outlining the general requirements for DAPs. Unlike most guidance documents issued by the FDA, the DAP guidance when finalized will have the force of law because FDORA specifically dictates that the form and manner for submission of DAPs are specified in FDA guidance. InOn January 27, 2025, in response to an executive order issued by the President Trumpearlier in January 2025 on Diversity, Equity and Inclusion programs, the FDA removed thisthe draft DAP guidance from its website. TheThat implicationsaction, along with similar actions by the current U.S. presidential administration to remove many other healthcare webpages, is currently the subject of ongoing litigation. In late July 2025, the FDA restored the draft DAP guidance to its website with a statement that “information on this page may be modified and/or removed in the future subject to the terms of the court’s order and implemented consistent with applicable law.” Accordingly, in light of these ongoing actions, there is considerable uncertainty surrounding the draft DAP guidance and how the FDA will consider diversity action areplans notin yetconnection known.with its review of marketing applications.

We plan to conduct clinical trials, including the INSPIRE DUCHENNE, IMPACT DUCHENNE trial,and ARTEMIS trials, with one or more trial sites that are located outside the United States. Although the FDA may accept data from clinical trials conducted at sites outside the United States, acceptance of these data is subject to conditions imposed by the FDA. For example, where data from foreign clinical trial sites are not intended to serve as the sole basis for approval in the United States, the FDA will not accept the data as support for a marketing application unless the clinical trial was well designed and conducted in accordance with GCP requirements. The FDA must also be able to validate the data from the trial through an onsite inspection, if necessary. Where data from foreign clinical trial sites are intended to serve as the sole basis for marketing approval in the United States, the FDA will generally not approve the application on the basis of foreign data alone unless (i) the data are applicable to the U.S. population and U.S. medical practice; (ii) the trials were performed by clinical investigators of recognized competence and pursuant to GCP regulations; and (iii) the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. In addition, these clinical trials are subject to the applicable local laws of the jurisdictions where the trials are conducted. There can be no assurance that the FDA will accept data from trials conducted outside of the United States. If the FDA does not accept the data from any trial that we conduct outside the United States, it would likely result in the need for additional trials, which would be costly and time-consuming and could delay or permanently halt our development of the applicable product candidates.

The EU Clinical Trials Regulation,Regulation or CTR,(“CTR”) which was adopted in April 2014 and repeals the EU Clinical Trials Directive, became applicable on January 31, 2022. The CTR aims to simplify and streamline the authorization, conduct and transparency of clinical trials in the EU.European Union. We have notonly previouslyrecently secured authorization to conduct clinical trials in the European Union pursuant to the CTR and, accordingly, there is a risk that we may be delayed in commencing any such studies. If we are slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies governing clinical trials, our development plans may be impacted.

Even if we complete the necessary clinical trials, we cannot predict when, or if, we will obtain regulatory approval to commercialize our Candidates and the approval may be for a narrower indication than we seek.

In addition, manufacturers of approved products and those manufacturers’ facilities are required to comply with extensive FDA requirements, including ensuring that quality control and manufacturing procedures conform to cGMPs applicable to drug manufacturers or quality assurance standards applicable to medical device manufacturers, which include requirements relating to quality control and quality assurance as well as the corresponding maintenance of records and documentation and reporting requirements. We, any contract manufacturers we may engage in the future, our future collaborators and their contract manufacturers will also be subject to other regulatory requirements, including submissions of safety and other post-marketingpost‑marketing information and reports, registration and listing requirements, requirements regarding the distribution of samples to clinicians, recordkeeping, and costly post-marketing studies or clinical trials and surveillance to monitor the safety or efficacy of the product such as the requirement to implement a REMS.

Finally, our ability to develop and market new drug products may be impacted by litigation challenging the FDA’s approval of another company’s drug product. In April 2023, the U.S. District Court for the Northern District of Texas invalidated the approval by the FDA of mifepristone, a drug product which was originally approved in 2000 and whose distribution is governed by various measures adopted under a REMS. The Court of Appeals for the Fifth Circuit declined to order the removal of mifepristone from the market but did hold that plaintiffs were likely to prevail in their claim that changes allowing for expanded access of mifepristone, which the FDA authorized in 2016 and 2021, were arbitrary and capricious. In June 2024, the Supreme Court reversed that decision after unanimously finding that the plaintiffs did not have standing to bring this legal action against the FDA. On October 11, 2024, the Attorneys General of three states filed an amended complaint in the U.S. District Court for the Northern District of Texas challenging the FDA’s actions. On January 16, 2025, the District Court agreed to allow these states to file an amended complaint and continue to pursue this challenge. Thereafter, on September 30, 2025, the District Court declined to dismiss the case and, instead, transferred it to federal District Court in the Eastern District of Missouri. Depending on the outcome of this litigation our ability to develop new drug Candidates and to maintain approval of existing drug products could be delayed, undermined or subject to protracted litigation.

Non-compliance with European Union requirements regarding safety monitoring or pharmacovigilance, and with requirements related to the development of products for the pediatric population, can also result in significant financial penalties. Similarly, failure to comply with the European Union’s requirements regarding the protection of personal information can also lead to significant penalties and sanctions. Further, similar restrictions apply to approved products in the EU.European Union. The holder of a marketing authorization is required to comply with a range of requirements applicable to the manufacturing, marketing, promotion and sale of medicinal products. These include: compliance with the EU’s stringent pharmacovigilance or safety reporting rules, which can impose post-authorization studies and additional monitoring obligations; the manufacturing of authorized medicinal products, for which a separate manufacturer’s license is mandatory; and the marketing and promotion of authorized drugs, which are strictly regulated in the EUEuropean Union and are also subject to EU Member State laws.

The regulations relating to the promotion of products for unapproved uses are complex and subject to substantial interpretation by the FDA, EMA, Medicines and Healthcare products Regulatory Agency,Agency or MHRA,(“MHRA”), and other government agencies. In September 2021, the FDA published final regulations which describe the types of evidence that the agency will consider in determining the intended use of a drug product. Physicians may nevertheless prescribe our products off-label to their patients in a manner that is inconsistent with the approved label. We intend to implement compliance and training programs designed to ensure that our sales and marketing practices comply with applicable regulations. Notwithstanding these programs, the FDA or other government agencies may allege or find that our practices constitute prohibited promotion of our products for unapproved uses. We also cannot be sure that our employees will comply with company policies and applicable regulations regarding the promotion of products for unapproved uses.

In addition, we could be adversely affected by several significant administrative law cases decided by the U.S. Supreme Court in 2024. In Loper Bright Enterprises v. Raimondo, for example, the court overruled Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., which for 40 years required federal courts to defer to permissible agency interpretations of statutes that are silent or ambiguous on a particular topic. The Supreme Court stripped federal agencies of this presumptive deference and held that courts must exercise their independent judgment when deciding whether an agency, such as the FDA, acted within its statutory authority under the Administrative Procedure Act,Act or (the APA.“APA”). Additionally, in Corner Post, Inc. v. Board of Governors of the Federal Reserve System, the court held that actions to challenge a federal regulation under the APA can be initiated within six years of the date of injury to the plaintiff, rather than the date the rule is finalized. The decision appears to give prospective plaintiffs a personal statute of limitations to challenge longstanding agency regulations. Another decision, Securities and Exchange Commission v. Jarkesy, overturned regulatory agencies’ ability to impose civil penalties in administrative proceedings. These decisions could introduce additional uncertainty into the regulatory process and may result in additional legal challenges to actions taken by federal regulatory agencies, including the FDA and CMS,Centers for Medicare & Medicaid Services (the “CMS”), that we rely on. In addition to potential changes to regulations as a result of legal challenges, these decisions may result in increased regulatory uncertainty and delays and other impacts, any of which could adversely impact our business and operations.

In recent years, a significant number of pharmaceutical and biotechnology companies have been the target of inquiries and investigations by various federal and state regulatory, investigative, prosecutorial and administrative entities in connection with the promotion of products for unapproved uses and other sales practices, including the Department of Justice and various U.S. Attorneys’ Offices, the Office of Inspector General of the Department of Health and Human Services,Services or HHS,(“HHS”), the FDA, the Federal Trade Commission,Commission or the FTC,(“FTC”), and various state Attorneys General offices. These investigations have alleged violations of various federal and state laws and regulations, including claims asserting antitrust violations, violations of the Federal Food, Drug, and Cosmetic Act, the False Claims Act, the Prescription Drug Marketing Act and anti-kickback laws and other alleged violations in connection with the promotion of products for unapproved uses, pricing and Medicare and/or Medicaid reimbursement. Many of these investigations originate as “qui tam” actions under the False Claims Act. Under the False Claims Act, any individual can bring a claim on behalf of the government alleging that a person or entity has presented a false claim or caused a false claim to be submitted to the government for payment. The person bringing a qui tam suit is entitled to a share of any recovery or settlement. Qui tam suits, also commonly referred to as “whistleblower suits,” are often brought by current or former employees. In a qui tam suit, the government must decide whether to intervene and prosecute the case. If it declines, the individual may pursue the case alone.

Even if we receive FDA approval of one or more of our Candidates in the United States, approval of a Candidate in the United States by the FDA does not ensure approval of such Candidate by regulatory authorities in other countries or jurisdictions, and approval by one foreign regulatory authority does not ensure approval by regulatory authorities in other foreign countries or by the FDA. Future sales of our Candidates outside of the United States will be subject to foreign regulatory requirements governing clinical trials, manufacturing and marketing approval. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from, and more onerous than, those in the United States, including additional preclinical studies or clinical trials. In many countries outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that country. If we submit a marketing authorization application,application or MAA,(“MAA”) to the EMA for approval of SGT-003, SGT-212SGT-212, SGT-501 or other Candidates in the European Union, obtaining such approval from the European Commission following the opinion of the EMA is a lengthy and expensive process. Regulatory authorities in countries outside of the United States and the European Union also have requirements for approval of product candidates with which we must comply prior to marketing in those countries. Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs for us and could delay or prevent the introduction of our Candidates in certain countries.

Additionally, we could face heightened risks with respect to obtaining marketing authorization in the United Kingdom as a result of the withdrawal of the United Kingdom from the European Union, commonly referred to as Brexit. The United Kingdom is no longer part of the European Single Market and EU Customs Union. As of January 1, 20252025, the MHRA is responsible for approving all medicinal products destined for the UK market (i.e., Great Britain and Northern Ireland), and the EMA will no longer have any role in approving medicinal products destined for Northern Ireland. On April 28, 2025, the United Kingdom Parliament adopted amendments to improve and strengthen the United Kingdom’s clinical trials regulatory regime, which are scheduled to take effect on April 28, 2026. Any delay in obtaining, or an inability to obtain, any marketing authorizations, as a result of Brexit or otherwise, may force us to restrict or delay efforts to seek regulatory approval in the United Kingdom for our Candidates, which could significantly and materially harm our business.

In addition, foreign regulatory authorities may change their approval policies and new regulations may be enacted. For instance, the EU pharmaceutical legislation is currently undergoing a complete review process, in the context of the Pharmaceutical Strategy for Europe initiative, launched by the European Commission in November 2020. The European Commission’s proposal for revision of several legislative instruments related to medicinal products (including potentially reducing the duration of regulatory data protection, revising the eligibility for expedited pathways, etc.) was published on April 26, 20232023, with several amendments requested in April 2024. TheIn proposedDecember revisions remain to be agreed and adopted by2025, the European Parliament and European Council andreached a provisional political agreement on the proposalsrevision mayof thereforeEU bepharmaceutical substantially revised before adoption,legislation, which is notexpected anticipatedto beforebe earlyadopted 2026.by Themid-2026. revisionsKey may,changes however,include updating regulatory data exclusivity to a new system with a regulatory data protection period of eight years and a reduced market exclusivity period of one year (which can be extended if specific conditions are fulfilled), adding launch/supply obligations, incentivizing antibiotic innovation with transferable vouchers, and streamlining approval procedures in the EU. If the legislation is finalized in line with the provisional political agreement, it will have a significant impact on the pharmaceutical industry and our business in the long term.industry.

Regulatory requirements governing gene therapy products have changed frequently and will likely continue to change in the future. Moreover, there is substantial, and sometimes uncoordinated, overlap in those responsible for regulation of gene therapy products. For example, in the United States, the FDA has established the Office of Therapeutic Products within the Center for Biologics Evaluation and Research,Research or the CBER,(“CBER”) to consolidate the review of gene therapy and related products, and the Cellular, Tissue and Gene Therapies Advisory Committee to advise CBER on its review. Gene therapy clinical trials may also be subject to review and oversight by an institutional biosafety committee, a local institutional committee that reviews and oversees basic and clinical research conducted at the institution participating in the clinical trial. 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.

The FDA has granted orphan drug designation to SGT-003 for the treatment of DuchenneDuchenne, andSGT-212 for the FDAtreatment of FA and EMA have granted orphan drug designation to SGT-501 for the treatment of CPVT.

The FDA Reauthorization Act of 2017,2017 or FDARA,(“FDARA”) requires that a drug sponsor demonstrate the clinical superiority of an orphan drug that is otherwise the same as a previously approved drug for the same rare disease in order to receive orphan drug exclusivity. FDARA reverses prior precedent holding that the Orphan Drug Act unambiguously requires that the FDA recognize the orphan exclusivity period regardless of a showing of clinical superiority.

We may seek a breakthrough therapy designation for one or more of our Candidates; however, we cannot assure our stockholders that one or more of our Candidates will meet the criteria for that designation. A breakthrough therapy is defined as a therapy that is intended, alone or in combination with one or more other therapies, to treat a serious condition, and preliminary clinical evidence indicates that the therapy may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints, such as substantial treatment effects observed early in clinical development. For therapies and biologics that have been designated as breakthrough therapies, interaction and communication between the FDA and the sponsor of the trial can help to identify the most efficient path for clinical development while minimizing the number of patientsparticipants placed in ineffective control regimens. Therapies designated as breakthrough therapies by the FDA may also be eligible for priority review if supported by clinical data at the time the BLA is submitted to the FDA.

We may seek approval of one or more of our Candidates using the FDA’s accelerated approval pathway. A product may be eligible for accelerated approval if it treats a serious or life-threatening condition and generally provides a meaningful advantage over available therapies. In addition, it must demonstrate an effect on a surrogate or intermediate endpoint that is reasonably likely to predict clinical benefit or on a clinical endpoint that can be measured earlier than irreversible morbidity or mortality,mortality or IMM,(“IMM”) that is reasonably likely to predict an effect on IMM or other clinical benefit. The FDA or other applicable regulatory agency makes the determination regarding whether a surrogate or intermediate endpoint is reasonably likely to predict long-term clinical benefit. Given that expression of microdystrophin has not yet been established to predict long-term clinical benefit, it is not currently accepted, and it is possible the FDA and/or other applicable regulatory agencies could decide never to accept it, as a surrogate endpoint for the accelerated approval pathway for the treatment of Duchenne.

We are a life sciences company focused on advancing a portfolio of current and future gene therapy candidates, which we refer to collectively as our Candidates, including SGT-003 for the treatment of Duchenne muscular dystrophy,dystrophy or Duchenne,(“Duchenne”), SGT-212 for the treatment of Friedreich'sFriedreich’s ataxia,ataxia or FA,(“FA”), SGT-501 for the treatment of Catecholaminergiccatecholaminergic polymorphic ventricular tachycardia,tachycardia or CPVT,(“CPVT”), SGT-601 for the treatment of TNNT2-mediated dilated cardiomyopathy,cardiomyopathy or (“TNNT2 DCM,DCM”), and additional assets for the treatment of genetic cardiac and otherneuromuscular diseases, at different stages of development, with varying levels of investment. We are advancing our diverse pipeline across rare neuromuscular and cardiac diseases, bringing together experts in science, technology, disease management and care. Patient-focused and founded by those directly impacted by Duchenne, our mission is to improve the daily lives of patients living with these devastating diseases.

build innovative libraries of delivery capsids and other enabling technologies with the potential to have broad impact on the gene therapy field at large:;

PatientParticipant dosing in the Phase 1/2 INSPIRE DUCHENNE trial of SGT-003 began in the second quarter of 2024. The INSPIRE DUCHENNE trial is a Phase 1/2 first-in-human, open-label, single-dose, multicenter trial designed to evaluate the safety, tolerability and efficacy of SGT-003 in pediatric patients with Duchenne at a dose of 1E14vg/kg. SGT-003 is administered as a one-time intravenous infusion. InSince Septemberinitiation 2024,of the INSPIRE DUCHENNE clinical trial, we amended the INSPIRE DUCHENNE clinical trial protocol to increase the anticipated participant enrollment size, expand the participant cohort age groups, and extend the timepointstime points of certain secondary objective measurements. In connection with the expanded clinical trial, we have initiated work for additional Good Manufacturing Practices (“GMP”) batches of SGT-003.SGT‑003.

SGT-003 was well-tolerated in the first six participants dosed as of February 11, 2025. For a full description of the initial results from the INSPIRE DUCHENNE trial, see Part I, Item I, “Business” appearing in this Annual Report on Form 10-K.

We are currently developing a preclinical stage product candidate, SGT-601, for the treatment of TNNT2 DCM. Efficacy studies in mice suggest that SGT-601 treatment resulted in a restoration of ejection fraction function and a stabilization in cardiac function over time. We anticipate submitting an IND to the FDA for SGT-601 for the treatment of TNNT2 DCM in the second half of 2026.

CapsidCapsids

We are focused on developing transformative treatments to improve the lives of patients with rare neuromuscular and cardiac diseases. The majority of our current programs are designed to treat these diseases with gene transfer products. Gene transfer, a type of gene therapy, is designed to address diseases caused by mutated genes through the delivery of functional versions of those genes, called transgenes. The transgenes are then utilized by the body to produce desired proteins that act therapeutically to treat the condition. In addition to a transgene, our gene transfer Candidates include a viral capsid or vector (a protein shell utilized as a vehicle to deliver a transgene to cells in the body) and a promoter (a specialized DNA sequence that directs cells to produce the protein in specific tissues). The capsid is modified to no longer self-replicate yet still retainretains its ability to introduce new genetic material directly into patients’ cells. Adeno-associated virus,virus or AAV,(“AAV”) capsids have been approved for use to deliver transgenes to patients, including via systemic delivery as well as stereotactic neurosurgical administration to the brain. The use of AAV capsids to deliver gene therapies has also been extensively studied by third parties in human clinical trials for multiple disease indications, and in certain of these trials AAV was delivered systemically to the patient.participant.

As we seek to develop and commercialize our Candidates, we anticipate that our expenses will increase significantly and that we will need substantial additional funding to support our continuing operations. Until such time as we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity financings,financing, debt financings or other sources, which may include licensing agreements or strategic collaborations. We may be unable to raise additional funds or enter into such agreements or arrangements when needed on favorable terms, if at all. If we fail to raise capital or enter into such agreements as and when needed, we may have to significantly delay, scale back or discontinue the development or commercialization of our Candidates.

As of December 31, 2024,2025, we had cash, cash equivalents, and available-for-sale securities of $148.9$187.9 million, excluding restricted cash of $2.0 million. In FebruaryMarch 2025,2026, we issued and sold in ana underwrittenprivate offering,placement or (the February“March 20252026 Offering,Private 35,739,810Placement”), 14,973,257 shares of our common stock at a price per share of $4.03,$5.61, and, to certain investors in lieu of shares of common stock, pre-funded warrants to purchase 13,888,34027,807,482 shares of our common stock at a price per warrant of $4.029.$5.609. We received net proceeds of approximately $187.5$226.4 million, after deducting underwriting discounts and commissions and estimated offering costs. We believe that our cash, cash equivalents, and available-for-sale securities as of December 31, 2024,2025, together with the net proceeds from the FebruaryMarch 20252026 Offering,Private Placement, will enable us to fund our operating expenses and capital expenditure requirements into the first half of 2027.2028. We have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently anticipate.

We have not generated any commercial product revenue to date and do not expect to generatedo any product revenue from the sale of our productsso for the foreseeable future, if ever. If our development efforts for our Candidates are successful and result in marketing approval, we may generate commercial product revenue in the future from product sales.future.

expenses incurred under agreements with third parties, including contract research organizations,organizations or CROs,(“CROs”) that conduct research, preclinical and clinical activities on our behalf, as well as contract development and manufacturing organizations,organizations or CMOs,(“CDMOs”) that manufacture SGT-003, SGT-212, SGT-501, and other Candidates for use in our preclinical studies and clinical trials;

costs of outside consultants,consultants engaged to assist in our research and development activities, including their fees, equity-based compensation and related travel expenses;

Research and development activities are central to our business model. We are still in the early stages of development for most of our Candidates. Candidates in later stages of clinical development generally have higher development costs than those in preclinical development or in earlier stages of clinical development, primarily due to the increased size and duration of later-stagelater‑stage clinical trials. We expect that our research and development expenses will continue to increase for the foreseeable future if and as we continue to conduct clinical trials for SGT-003, initiate clinical trials for our otherINSPIRE Candidates,DUCHENNE, includingIMPACT ourDUCHENNE, plannedFALCON Phaseand 1bARTEMIS clinical trial of SGT-212,trials and continue to identifydevelop our pipeline and developcomplete additionalongoing and planned preclinical studies and clinical trials of our Candidates.

We cannot determine with certainty the duration, costs, and timing of ongoing and planned clinical trials of ongoing and planned SGT-003, SGT-212, SGT-501,SGT-501 or our other Candidates, or if, when, or to what extent we will generate revenue from the commercialization and sale of any of our Candidates for which we obtain marketing approval or our other research and development expenses. We may never succeed in obtaining marketing approval for any of our Candidates. The duration, costs, and timing of clinical trials and development of our Candidates will depend on a variety of factors, including:

uncertainties in clinical trial design and patientparticipant enrollment or drop out or discontinuation rates;

We expect that our general and administrative expenses will increase in the future as we support our research and development activities and activities related to our INSPIRE DUCHENNE trial, our plannedIMPACT PhaseDUCHENNE 1btrial, clinicalour FALCON trial, our ARTEMIS trial of SGT-212, and any other planned or future clinical trials for and potential commercialization of our Candidates.

Our management’s discussion and analysis of our financial condition and results of operations is based on our consolidated financial statements, which have been prepared in accordance with generally accepted accounting principles in the United States. The preparation of our consolidated financial statements and related disclosures requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities, costs and expenses and the disclosure of contingent assets and liabilities in our consolidated financial statements. We base our estimates on historical experience, known trends and events and various other factors that we believe 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. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ materially from these estimates.

We have equity plans under which we makegrant equity awards to employees, directors and non-employees. We measure all stock options and other stock-based awards granted to employees, directors and non-employees based on the fair value on the date of the grant and recognize compensation expense of those awards, over the requisite service period, which is generally the vesting period of the respective award. Forfeitures are accounted for as a reduction of equity based compensation as they occur. We apply the straight-line method of expense recognition to all awards with only service-based vesting conditions. For performance-based restricted stock unit awards, which are subject to the achievement of performance milestones, the fair value is recognized as expense over the requisite service periods when the achievement of such performance milestones is determined to be probable. If a performance milestone is not determined to be probable or is not met, no equity-based compensation expense is recognized, and any previously recognized expense is reversed. For stock-based awards granted to non-employees, compensation expense is recognized over the period during which services are rendered by such non-employeesnon‑employees until completed.

The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes option-pricing model. InWe use the first quartervolatility of 2024,our we determined that we have adequateown historical stock price data to utilize solely our stock for historical volatility purposes.price. The expected term of stock options with service-based vesting conditions and options granted to non-employees has been determined utilizing the “simplified” method for awards that qualify as “plain-vanillaplain‑vanilla” options. The risk-free interest rate is determined by reference to the U.S. Treasury yield curve in effect at the time of grant of the award for time periods approximately equal to the expected term of the award. We use a 0% expected dividend yield in our determination of fair value based on the fact that we have never paid cash dividends and do not expect to pay any cash dividends in the foreseeable future, if ever.

In connection with the asset purchase agreement with FA212 LLC,LLC or FA212,(“FA212”), certain development milestone payments to FA212 are payable in either cash, equity, or a combination of both, at our discretion. Such contingent payments were determined to be derivative liabilities.

Research and development expenses for the year ended December 31, 20242025 were $96.4$140.3 million, compared to $76.6$96.4 million for the year ended December 31, 2023.2024. The increase of $19.9$43.9 million in research and development expenses was primarily relateddue to a $14.0$43.8 million increase in costs for SGT-501SGT-003 fromprimarily increasedrelated to manufacturing and study relatedclinical costs, a $4.6$10.3 million increase in personnel related expenses, a $5.0 million increase in costs for SGT-212SGT-601 primarily related to the entry into the asset purchase agreement with FA212, and a $6.7 million increase in license feesmanufacturing and research and consulting costs for other development programs,costs, partially offset by a $5.7net decrease of $7.6 million in costs for SGT-501 related to lower manufacturing and study costs partially offset by an increase in clinical, regulatory and licensing fees, and a $6.0 million decrease in costs for SGT-003other relateddevelopment to manufacturing and study related costs.programs.

General and administrative expenses were $38.9 million for the year ended December 31, 2025, compared to $33.3 million for the year ended December 31, 2024, compared to $27.8 million for the year ended December 31, 2023.2024. The increase of $5.5$5.6 million was primarily related to a $4.1$6.1 million increase in personnel related costs and a $1.4$0.6 million increase in information technology support and services, partially offset by a $1.1 million decrease in general legal fees.

Other income, net was $5.0$4.9 million and $8.2$5.0 million for the years ended December 31, 20242025 and 2023,2024, respectively. The decrease of $3.2$0.2 million was primarily related to a $4.8 million expense for athe change in fair value of derivative liabilities, partiallyliabilities offset by a $1.9 million increase in interest income primarily related to available-for-sale securities included within our portfolio.income.

To date, we have financed our operations primarily through the sale of redeemable preferred units and member units, the sale of securities in private placements and follow-on offerings, the sale of common stock in our initial public offering, and sales of common stock under our “at-the-market offering” sales agreement with Jefferies LLC,LLC or(“Jefferies”) Jefferies, or (the “ATM Sales Agreement.Agreement”). Through December 31, 2024,2025, we raised an aggregate of $144.6 million of gross proceeds from our sales of preferred units prior to the completion of our initial public offering, and an aggregate of $668.9$863.7 million of net proceeds from the sale of our common stock through public offerings, including our IPO and follow-on public offering,offerings, private placements, the ATM Sales Agreement, and pursuant to the stock purchase agreements.

On January 11, 2024, we issued and sold 16,973,103 shares of our common stock at a price per share of $5.53 and, to one investor in lieu of shares of common stock, pre-funded warrants to purchase 2,712,478 shares of common stock at a price of $5.529 per pre-funded warrant, in a private placement,placement which we refer to as (the “January 2024 Private Placement.Placement”). We received $103.7 million of net proceeds from the January 2024 Private Placement after deducting offering costs.

On February 19, 2025, we issued and sold in an underwritten offering (the “February 2025 Offering”), 35,739,810 shares of our common stock at a price of $4.03 per share,share and, to certain investors in lieu of shares of common stock, pre-funded warrants to purchase 13,888,340 shares of our common stock at a price of $4.029 per pre-funded warrant. We received approximately $187.5$188.0 million of net proceeds from the February 2025 Offering, after deducting underwriting discounts and commissions and estimated offering costs.

During the year ended December 31, 2024,2025, operating activities used $100.0$156.3 million of cash, primarily resulting from our net loss of $124.7$174.3 million offset by non-cash charges of $21.8$24.9 million due primarily to equity-based compensation of $10.5$16.9 million, an increase in the fair value of the derivative liabilities of $4.8 million, non-cash acquired in-process research and development of $3.4 million, depreciation expense of $2.5$6.1 million, non-cash lease expense of $2.4 million, and adepreciation non-cash up-front equity payment for a collaboration and license agreementexpense of $2.0$1.6 million, partially offset by amortization of discount on available-for sale-securities of $3.6$1.9 million. Net cash providedused by changes in our operating assets and liabilities was $2.9$6.8 million which included an increase in prepaid expenses of $4.8$8.0 million, a decrease in operating lease liability of $1.8 million, and a decrease in accounts payable of $1.1 million, partially offset by an increase of $4.1 million in accrued expenses and other current and non-current liabilities, and an increase in accounts payable of $2.2 million, partially offset by an increase in prepaid expenses and other current and non-current assets of $2.4 million and a decrease in operating lease liability of $1.7 million.liabilities.

During the year ended December 31, 2023,2024, operating activities used $94.2$100.0 million of cash, primarily resulting from our net loss of $96.0$124.7 million offset by non-cash charges of $10.7$21.8 million due primarily to equity-based compensation of $7.6$10.5 millionmillion, an increase in the fair value of the derivative liabilities of $4.8 million, non-cash acquired in-process research and development of $3.4 million, depreciation and impairment expense of $2.6$2.5 million, non-cash lease expense of $2.5$2.4 million, and a non-cash upfront equity payment for a collaboration and license agreement of $2.0 million, partially offset by amortization of discount on available-for sale-securities of $2.4$3.6 million. Net cash usedprovided by changes in our operating assets and liabilities was $8.9$2.9 million which included aan decreaseincrease of $6.9$4.8 million in accrued expenses and other current and non-current liabilities, and an increase in accounts payable of $2.2 million, partially offset by an increase in prepaid expenses and other current and non‑current assets of $2.4 million and a decrease in operating lease liability of $1.7 million, and a decrease in accounts payable of $0.8 million, partially offset by a decrease in prepaid expenses and other current and non-current assets of $0.6 million.

During the year ended December 31, 2024,2025, investing activities used $16.1$58.5 million of cash, resulting from the purchases of available-for sale securities of $204.3$235.9 million and the purchases of property and equipment of $0.7$1.2 million, partially offset by the maturitysales and maturities of available-for sale securities of $188.9$178.5 million.

During the year ended December 31, 2023,2024, investing activities providedused cash$16.1 million of $9.7cash, million,resulting consistingfrom primarilythe purchases of theavailable-for sale of available-for-sale securities of $128.6 million, partially offset by net purchases of available-for-sale securities of $117.4$204.3 million and the purchasepurchases of property and equipment of $1.5$0.7 millionmillion, primarilypartially relatedoffset toby the corporatematurities headquartersof lease.available-for sale securities of $188.9 million.

During the year ended December 31, 2024,2025, financing activities provided $122.4$194.4 million of cash, primarily resulting from the net proceeds from the issuance and sale of common stock and pre-funded warrants to purchase shares of common stock in the January 2024 Private Placement of $103.7 million and net proceeds from the sale of common stock under the ATM Sales Agreement of $18.4 million, proceeds from the exercise of common stock options of $0.5$194.7 million, and proceeds from the issuance of shares of $0.4 million under the Company'sour Amended and Restated 2021 Employee Stock Purchase Plan,Plan or ESPP, of $0.3 million, partially(“ESPP”), offset by payments of the principal portion of finance lease obligations of $0.5$0.7 million.

continue to enroll patientsparticipants in our INSPIRE DUCHENNEDUCHENNE, trialIMPACT DUCHENNE, FALCON and ARTEMIS trials and advance clinical development of SGT-003SGT-003, SGT-212 and SGT-501;

advance our other Candidates into clinical trials, including our planned Phase 1b clinical trial of SGT-212trials;

Since inception, we have incurred significant net losses. Our net losses were $56.7$111.5 million and $39.3$78.8 million for the threesix months ended MarchJune 31,30, 2026 and 2025, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $1.0$1.1 billion. Prior to our acquisition of AavantiBio, Inc. in December 2022 (the “Acquisition”) we devoted substantially all of our efforts to research and development, including clinical development of SGT-001, which we are no longer developing, and preclinical development of SGT‑003, as well as to building out our management team and infrastructure. Following the Acquisition, we have devoted our efforts to the research and development of our other Candidates, including clinical development of SGT‑003, SGT‑212 and SGT-501, as well as building out our management team. We expect that it could be several years before we have a commercialized product, and we may never have a commercialized product. We expect to incur significant expenses and operating losses for the foreseeable future. We anticipate that our expenses will increase substantially if, and as, we:

We expect our expenses to increase in connection with our ongoing activities, particularly as we continue the research and development of, conduct clinical trials of, and seek marketing approval for our Candidates. In addition, if we obtain marketing approval for our Candidates, we expect to incur significant expenses related to product sales, marketing, manufacturing and distribution. We also expect to continue to incur additional costs associated with operating as a public company. While we believe that our cash, cash equivalents and available-for-sale securities as of MarchJune 31,30, 2026 will be sufficient to fund our operating expenses and capital requirements into the first half of 2028,mid-2028, we have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently anticipate. In order to continue to operate our business beyond that time, we will need to raise additional funds. However, there can be no assurance that we will be able to generate funds on terms acceptable to us, on a timely basis, or at all. In addition, we anticipate that we will need additional funding to complete the development of our Candidates.

In addition, our ability to conduct and complete our preclinical development testing and studies is contingent on our ability to source animals and other supplies required for the conduct of such testing and studies and the performance of animal models. If we are unable to obtain all necessary animals and other supplies required for the conduct of our preclinical testing and studies, or the animal models do not perform as expected, we may be unable to complete such preclinical development testing and studies in a timely manner or at all. For example, some of our IND-enabling toxicology and other studies require certain non-human primates ("NHPs") that may be imported from countries in which trade relation with the U.S. are or may become challenging or through vendors who may not be able to timely source certain NHPs or at all, which may impair our ability to complete preclinical development testing and studies to support IND or similar applications or delay submission of such applications. Additionally, we may fail to demonstrate adequate Candidate efficacy and/or safety as required by regulatory authorities. We may fail to access relevant, adequate, or necessary animal models, including genetic models of disease and non-human primatesNHPs in particular, for use in such studies as requested by regulatory authorities. We may also experience substantial delays as a result of our reliance on contract research organizations (“CROs”) to conduct all animal model experimentation necessary to assess the efficacy and safety of our Candidates. Any of these factors may result in delays to Candidate progression, inability to obtain regulatory approval, and/or substantial increases in Candidate development costs.

During the conduct of clinical trials, participants may experience changes in their health, including illnesses, injuries, discomforts or a fatal outcome. Often, it is not possible to determine whether the Candidate being studied caused these conditions. For instance, we reported a serious adverse event in IGNITE DMD, which resulted in a clinical hold in November 2019, which has since been resolved. In April 2021, a participant treated with SGT-001 in IGNITE DMD experienced a systemic inflammatory response classified as a serious adverse event and considered by the investigator to be drug related. In addition, there hashave been onetwo previously disclosed treatment-related serious adverse eventevents in the INSPIRE DUCHENNE trialtrial. asBoth events were reviewed by the data and safety monitoring board with the recommendation to continue dosing without interruption, and both events have resolved; however, we cannot guarantee that similar events will not happen in ongoing and future clinical trials of May 11, 2026, identified as a Grade 3 immune‑mediated myositis.SGT-003.

Additionally, we could face heightened risks with respect to obtaining marketing authorization in the United Kingdom as a result of the withdrawal of the United Kingdom from the European Union, commonly referred to as Brexit. The United Kingdom is no longer part of the European Single Market and EU Customs Union. As of January 1, 2025, the MHRA is responsible for approving all medicinal products destined for the UK market (i.e., Great Britain and Northern Ireland), and the EMA will no longer have any role in approving medicinal products destined for Northern Ireland. On April 28, 2025, the United Kingdom Parliament adopted amendments to improve and strengthen the United Kingdom’s clinical trials regulatory regime, which are scheduled to taketook effect on April 28, 2026. Any delay in obtaining, or an inability to obtain, any marketing authorizations, as a result of Brexit or otherwise, may force us to restrict or delay efforts to seek regulatory approval in the United Kingdom for our Candidates, which could significantly and materially harm our business.

In addition, foreign regulatory authorities may change their approval policies and new regulations may be enacted. For instance, the EU pharmaceutical legislation is currently undergoing a complete review process, in the context of the Pharmaceutical Strategy for Europe initiative, launched by the European Commission in November 2020. The European Commission’s proposal for revision of several legislative instruments related to medicinal products (including potentially reducing the duration of regulatory data protection, revising the eligibility for expedited pathways, etc.) was published on April 26, 2023, with several amendments requested in April 2024. In December 2025, the European Parliament and European Council reached a provisional political agreement on the revision of EU pharmaceutical legislation, which is expected to be adopted by mid-2026.late-2026. Key changes include updating regulatory data exclusivity to a new system with a regulatory data protection period of eight years and a reduced market exclusivity period of one year (which can be extended if specific conditions are fulfilled), adding launch/supply obligations, incentivizing antibiotic innovation with transferable vouchers, and streamlining approval procedures in the EU. If the legislation is finalized in line with the provisional political agreement, it will have a significant impact on the pharmaceutical industry.

In 2025, the Trump Administration imposed a series of tariffs against U.S. trading partners pursuant to the International Emergency Economic Powers Act. On February 20, 2026, the U.S. Supreme Court ruled these tariffs unlawful. The Trump Administration immediately imposed new global tariffs pursuant to Section 122 of the Trade Act of 1974, which allows for tariffs of up to 15% for a period of up to 150 days. Pursuant to the statute, these tariffs expired on July 24, 2026. However, on July 23, 2026, the Office of the U.S. Trade Representative announced final action under Section 301 of the Trade Act of 1974 imposing new tariffs on imports from 60 trading partners based on findings that those countries had failed to adopt and effectively enforce prohibitions on imports of goods produced with forced labor. The new tariffs, set at either 10% or 12.5% depending on the country’s level of commitment to forced-labor import restrictions, took effect on July 24, 2026, and replaced the tariffs that had been imposed under Section 122.

Separately, in April 2025, the Department of Commerce announced an investigation under Section 232 of the Trade Expansion Act of 1962 into imports of pharmaceuticals and pharmaceutical ingredients, including finished products, medical countermeasures, critical inputs such as active pharmaceutical ingredients, and key starting materials, and derivative products of those items. OnU.S. Septembertrade 25,policy 2025,remains viasubject to uncertainty and, accordingly, a post on Truth Social, President Trump announced that, beginning October 1, 2025, all branded or patented drugs imported in the United States would face a 100% tariff. At the same time, President Trump indicated that these tariffs could be avoided by building pharmaceutical manufacturing facilities in the United States. Thereafter, President Trump delayed the October 1, 2025 effective date of the tariffs on branded or patented pharmaceutical products announcing that the Trump Administration had now “begun preparing” tariffs on manufacturers that do not build in the United States or enter into a most-favored-nation drug pricing agreement with the Trump Administration. A host of other U.S. tariff actions remain possible, including additional 25% tariffs on products from countries that do certain business with Iran or Cuba.possible.

We are a life sciences company focused on advancing a portfolio of current and future gene therapy candidates, which we refer to collectively as our Candidates, including SGT-003 for the treatment of Duchenne muscular dystrophy (“Duchenne”), SGT-212 for the treatment of Friedreich’s ataxia (“FA”), SGT-501 for the treatment of catecholaminergic polymorphic ventricular tachycardia (“CPVT”), SGT-601 for the treatment of TNNT2-mediated dilated cardiomyopathy (“TNNT2 DCM”), and additional assets for the treatment of genetic cardiac and neuromuscular diseases, at different stages of development, with varying levels of investment. The Company is also focused on developing innovative libraries of genetic regulators and other enabling technologies with promising potential to significantly impact gene therapy delivery cross-industry. We are advancing our diverse pipeline across rare neuromuscular and cardiac diseases, bringing together experts in science, technology, disease management and care. Patient-focused and founded by those directly impacted by Duchenne, our mission is to improve the daily lives of patients living with these devastating diseases.

Solid was purpose-built to advance the best science and accelerate the discovery and development of treatments that may benefit all patients with Duchenne. As we expand to bring meaningful treatments to patients living with other neuromuscular and cardiac diseases, the values and guiding principles that drive us continue. Our corporate vision is to build an innovation platform enabling the discovery and development of high-value genetic medicines for neuromuscular and cardiac diseases by integrating internal capabilities, including a vector core, use of validated animal models, optimized expression cassettes, novel platform technologies including capsids and regulatory expertise, and collaborations with leaders in related clinical and research fields. Our mission, which guides our operations, is to treat and change the course of neuromuscular and cardiac diseases at all stages. Underscoring this mission, our disease-focused business model is founded on the following fundamental principles:

We are continuing to advance our pipeline of Candidates. The U.S. Food and Drug Administration (the “FDA”) has granted Fast Track, Orphan Drug,Drug and Rare Pediatric Disease designations for SGT-003 for Duchenne, and SGT-003 has also been awarded Orphan Drug designation from the European Commission for the treatment of Duchenne, in addition to an Innovation Passport by the new UK Innovative Licensing and Access Pathway, which aims to accelerate time to market and facilitate patient access to new medicines in the United Kingdom. The FDA has granted Fast Track, Orphan Drug and Rare Pediatric Disease designations to SGT-212 for the treatment of FA and SGT-501 for the treatment of CPVT.

Participant dosing in the Phase 1/2 INSPIRE DUCHENNE trial of SGT-003 began in the second quarter of 2024. The INSPIRE DUCHENNE trial is a Phase 1/2 first-in-human, open-label, single-dose, multicenter trial designed to evaluate the safety, tolerability and efficacy of SGT-003 in pediatric patients with Duchenne at a dose of 1E14vg/kg. SGT-003 is administered as a one-time intravenous infusion. Since initiation of the INSPIRE DUCHENNE clinical trial, we amended the clinical trial protocol to increase the anticipated participant enrollment size, expand the participant cohort age groups,groups and extend the time points of certain secondary objective measurements. In connection with the expanded clinical trial, we have initiated work for additional Good Manufacturing Practices (“GMP”) batches of SGT‑003.

SGT-003 has been generally well tolerated in the 4753 participants dosed in the Phase 1/2 INSPIRE DUCHENNE clinical trial as of MayAugust 11,4, 2026. One study participant withdrew consent after the Day 60 follow-up visit. No treatment-related adverse events were seen in this participant. The safety and tolerability profile observed in the INSPIRE DUCHENNE trial continued to be promising; SGT-003 is administered using a low-burden, steroid-only prophylactic immunomodulation regimen. As of MayAugust 11,4, 2026, there waswere onetwo previously disclosed treatment-related serious adverse eventevents reported in the INSPIRE DUCHENNE trial. This serious adverse event was identified as a Grade 3 immune-mediated myositis which, importantly, was not associated with muscle pain or weakness, and occurred in a participant who had a large deletion in a region coded for by SGT-003’s microdystrophin. The trial participant promptly responded to steroid treatment and the event has resolved. This serious adverse event was reviewed by the data and safety monitoring board with the recommendation to continue dosing without interruption.

Enrollment and dosing in theThe INSPIRE DUCHENNE trial is ongoing and being conducted at 15 clinical sites across the United States, Canada, Italy and the United Kingdom. We believe we have aligned with the FDA on SGT-003's potency assay strategy and will continue commercial-readiness CMC activities, with our process performance qualification manufacturing batches to be completed in 2026.

In October 2025, we activated the first clinical trial site and began screening participants for IMPACT DUCHENNE, a Phase 3 randomized, double-blind, placebo-controlled trial evaluating SGT-003. In February 2026, we announced positive feedback from a Type C meeting with the FDA where we reached alignment on the IMPACT DUCHENNE trial design, including: the patient population of ambulant participants 7 to <12 years of age, the primary endpoint of change from baseline in Time to Rise (TTR) velocity from supine position evaluated at 18 months and other key secondary endpoints. Clinical trial sites for IMPACT DUCHENNE are currently active in Australia and CanadaCanada, andwith additional clinical site activations in the UK and US are expected in the second half of 2026, with sites in the EU anticipatedsubject to follow,site subjectinitiation toactivities and regulatory clearances. Participant screening is underway and we dosed our first participant in the IMPACT DUCHENNE trial in April 2026.

We expectplan to continue discussionsmeet with the FDA aslate wein the fourth quarter of 2026 to discuss the INSPIRE DUCHENNE SGT-003 data package and to seek guidance on a potential accelerated approval pathway for SGT-003 and; we expect to provide an update as regulatory discussions progress.

The FDA has granted Fast Track, Orphan Drug,Drug and Rare Pediatric Disease designations for SGT-003 and the European Commission has granted Orphan drug designation for SGT-003 for the treatment of Duchenne. SGT-003 has been awarded an Innovation Passport by the new UK Innovative Licensing and Access Pathway, which aims to accelerate time to market and facilitate patient access to new medicines in the United Kingdom.

In January 2025, we announced that the FDA cleared our IND for SGT-212 for the treatment of FA. In October 2025, we activated the first clinical trial site and began screening participants for FALCON, an open-label, multi-center Phase 1b clinical trial of SGT-212, and in January 2026, we dosed the first participant in the trial. Two participants have been dosed in the FALCON clinical trial and SGT-212 has been well tolerated with no treatment related serious adverse events observed as of MayAugust 11,4, 2026.

The trial is expected to enroll approximately 10 non-ambulatory and ambulatory adult participants (aged 18-40) living with FA in up to three cohorts and is designed to evaluate the safety and tolerability of contemporaneous IDN and systemic IV infusion of SGT-212, with initial data anticipated byin the endfirst quarter of 2026,2027, subject to participant enrollment. The FDA has granted Fast Track, Orphan Drug and Rare Pediatric Disease designations to SGT-212 for the treatment of FA.

The Company is also focused on developing innovative enabling technologies, including next-generation capsids. In March of 2026, we began using the mark POLARIS-101TM to represent our AAV-SLB101 capsid (“POLARIS-101TM”). POLARIS‑101TM is our rationally designed, proprietary capsidcapsid, which is used in SGT-003 for Duchenne,Duchenne whichand has been generally well tolerated as of MayAugust 11,4, 2026 (N=4753), in the INSPIRE DUCHENNE clinical trial, and was also well tolerated in nonclinical NHP and mouse models. We aim to license POLARIS-101TM broadly to corporations, institutions and academic labs pursuing neuromuscular and cardiac rare disease research, with more than 50 agreements, including licenses, executed.

We are building additional cardiac and neuromuscular next-generation capsid and promoter libraries with capsid selection from the first library anticipated in the second half of 2026.

Due to our significant research and development expenditure, licensing and patent investment, and general and administrative costs associated with our operations, we have generated substantial operating losses in each period since our inception. Our net losses were $56.7$54.8 million and $39.3$111.5 million for the three and six months ended MarchJune 31,30, 20262026, respectively, and $39.5 million and $78.8 million for the three and six months ended June 30, 2025, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $1.0$1.1 billion. We expect to incur significant expenses and operating losses for the foreseeable future.

As we seek to develop and commercialize our Candidates, we anticipate that our expenses will increase significantly and that we will need substantial additional funding to support our continuing operations. Until we can generate significant revenue from product sales, if ever, we expect to finance our operations through a combination of public or private equity financing, debt financingsfinancing or other sources, which may include licensing agreements or strategic collaborations. We may be unable to raise additional funds or enter into such agreements or arrangements when needed on favorable terms, if at all. If we fail to raise capital or enter into such agreements as and when needed, we may have to significantly delay, scale back or discontinue the development or commercialization of our Candidates.

As of MarchJune 31,30, 2026, we had cash, cash equivalents, and available-for-sale securities of $380.7$377.7 million, excluding restricted cash of $1.3 million. We believe that our cash, cash equivalents, and available-for-sale securities as of MarchJune 31,30, 2026 will enable us to fund our operating expenses and capital expenditure requirements into the first half of 2028.mid-2028. We have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently anticipate.

During the threesix months ended MarchJune 31,30, 2026, there were no material changes to our critical accounting policies. Our critical accounting policies are described under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Use of Estimates” in our Annual Report on Form 10-K for the year ended December 31, 2025 and the notes to the unaudited condensed consolidated financial statements included in Part I, Item 1, “Financial Statements (unaudited),” of this Quarterly Report on Form 10-Q. We believe that of our critical accounting policies, the following accounting policies involve the most judgment and complexity:

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

Research and development expenses for the three months ended MarchJune 31,30, 2026 were $46.1$44.3 million, compared to $30.9$32.4 million for the three months ended MarchJune 31,30, 2025. The increase of $15.2$11.9 million in research and development expenses was primarily due to a $13.6$12.2 million increase in costs for SGT-003 primarily related to manufacturing and clinical costs, a $3.3$3.2 million increase in personnel related expenses, and a $2.5$1.2 million increase in costs for SGT-212 primarily related to clinical costs and licenseresearch and milestone payments, and a $0.4 million increase in external expenses primarily related to consulting and professional services,costs, partially offset by a $3.1 million decrease in costs for SGT-501 primarily related to lower manufacturing and research costs, and a $1.7$2.2 million decrease in costs for SGT-601 related to lower manufacturing and research costs, a $1.4 million decrease in external expenses primarily related to laboratory supplies, and a $1.3 million decrease in costs for SGT-501 primarily related to lower license payments and research costs.

General and administrative expenses were $11.2$13.1 million for the three months ended MarchJune 31,30, 2026, compared to $9.1$9.3 million for the three months ended MarchJune 31,30, 2025. The increase of $2.0$3.8 million was primarily related to a $1.5$2.6 million increase in personnel related costs, a $0.5 million increase in consultingbusiness services,development andcosts, a $0.4 million increase in equipment costs, partially offset byand a $0.5$0.3 million decreaseincrease in legalconsulting fees.services.

Other income, net was $0.6$2.6 million for the three months ended MarchJune 31,30, 2026 compared to $0.8$2.2 million for the three months ended MarchJune 31,30, 2025. The decreaseincrease of $0.2$0.4 million was primarily related to lowerhigher interest income from our available-for-sale securities.

To date, we have financed our operations primarily through the sale of securities in private placements and follow-on offerings, the sale of common stock in our initial public offering, and sales of common stock under our “at-the-market offering” sales agreement with Jefferies LLC (“Jefferies”) (the “ATM Sales Agreement”). Through MarchJune 31,30, 2026, we raised an aggregate of $144.6 million of gross proceeds from our sales of preferred units prior to the completion of our initial public offering, and an aggregate of $1.1$1.2 billion of net proceeds from the sale of our common stock through public offerings, including our IPO and follow-on public offerings, private placements, the ATM Sales Agreement, and pursuant to the stock purchase agreements.

On March 13, 2019, we entered into the ATM Sales Agreement, which was amended and restated in March 2024, under which we may offer and sell, from time to time, shares of our common stock through Jefferies as sales agent. Any such sales being made by any method that is deemed an “at-the-market offering” as defined in Rule 415 promulgated under the Securities Act. We will pay Jefferies a commission of up to 3% of the gross proceeds of any sales of common stock pursuant to the ATM Sales Agreement. During the year ended December 31, 2025, we sold 891,414 shares pursuant to the ATM Sales Agreement resulting in net proceeds of $5.1 million. During the threesix months ended MarchJune 31,30, 2026, we sold 1,937,6238,515,987 shares pursuant to the ATM Sales Agreement resulting in net proceeds of $11.9$60.8 million. In July 2026, the Company sold 2,012,500 shares of its common stock, pursuant to its ATM Sales Agreement for net proceeds of $15.7 million.

As of MarchJune 31,30, 2026, we had cash, cash equivalents, and available-for-sale securities of $380.7$377.7 million, excluding restricted cash of $1.3 million, and had no debtoutstanding outstanding.debt.

During the threesix months ended MarchJune 31,30, 2026, operating activities used $47.2$99.8 million of cash, primarily resulting from our net loss of $56.7$111.5 million partially offset byand changes in our operating assets and liabilities of $2.3$1.6 millionmillion, andpartially offset by non-cash charges of $7.2$13.4 million. Net cash used by changes in our operating assets and liabilities during the threesix months ended MarchJune 31,30, 2026 consisted of an increase in accounts payable of $2.3 million and a decrease in prepaid expenses and other assets of $1.0 million, offset by a decrease in accrued expenses and other liabilities of $0.5$1.4 million andmillion, a decrease in the operating lease liability of $0.5$1.0 million, and an increase in prepaid expenses and other assets of $0.3 million, offset by an increase in accounts payable of $1.1 million. Non-cash activities were driven by equity-based compensation of $5.2$10.8 million, a change in the fair value of derivative liabilities of $1.7$2.5 million, non-cash lease expense of $0.6$1.3 million, and depreciation and amortization expense of $0.4$0.8 million, partially offset by amortization of discount on available-for-sale securities of $0.6$2.0 million.

During the threesix months ended MarchJune 31,30, 2025, operating activities used $31.9$69.3 million of cash, primarily resulting from our net loss of $39.3$78.8 million partially offset by changes in our operating assets and liabilities of $1.8$0.7 million and non-cash charges of $5.6$10.2 million. Net cash used by changes in our operating assets and liabilities during the threesix months ended MarchJune 31,30, 2025 consisted of aan decrease of $2.0 millionincrease in prepaid expenses and other assets and an increase in accounts payable of $0.5$2.1 million, offset by a decrease in the operating lease liability of $0.4$0.8 millionmillion, andoffset aby decreasean increase in accrued expenses and other liabilities of $0.3$1.7 million, and an increase in accounts payable of $0.5 million. Non-cash activities were driven by equity-based compensation of $3.3$6.5 million, depreciation and amortization expense of $0.4 million, non-cash lease expense of $0.6 million, and a change in the fair value of derivative liabilities of $1.7$2.6 million, non-cash lease expense of $1.2 million, and depreciation and amortization expense of $0.8 million, partially offset by amortization onof available-for-sale securities of $0.3$0.8 million.

During the threesix months ended MarchJune 31,30, 2025,2026, investing activities used $27.5$88.8 million of cash, resulting from the purchases of available-for saleavailable-for-sale securities of $65.3$235.4 million and the purchases of property plant and equipment of $0.1$0.3 million, partially offset by the maturitymaturities of available-for saleavailable-for-sale securities of $38.0$146.9 million.

During the threesix months ended MarchJune 31,30, 2026, financing activities provided $239.0$287.5 million of cash, primarily resulting from the net proceeds from the issuance and sale of common stock and pre-funded warrants to purchase shares of common stock in the March 2026 Private Placement.Placement of $226.3 million, the sale of common stock in the ATM of $60.8 million, and proceeds from the issuance of $0.3 million of shares of common stock under the Company’s Amended and Restated 2021 Employee Stock Purchase Plan ("ESPP").

During the threesix months ended MarchJune 31,30, 2025, financing activities provided $189.7$188.1 million of cash, resulting from the net proceeds from the issuance and sale of common stock and pre-funded warrants to purchase shares of common stock inof $188.2 million, and proceeds from the February 2025 Offering, offset by paymentsissuance of the$0.2 principal portionmillion of finance lease obligationsshares of $0.1common million.stock under the Company's ESPP.

As of MarchJune 31,30, 2026, we had cash, cash equivalents and available-for-sale securities of $380.7$377.7 million, excluding restricted cash of $1.3 million. Based on our current operating plan, we believe that our cash, cash equivalents and available-for-sale securities as of MarchJune 31,30, 2026 will be sufficient to fund our operating expenses and capital requirements into the first half of 2028.mid-2028. As a result, in order to continue to operate our business beyond that time, we will need to raise additional funds. However, there can be no assurance that we will be able to generate funds on terms acceptable to us, on a timely basis, or at all. In addition, we have based this estimate on assumptions that may prove to be wrong, and we could use our available capital resources sooner than we currently anticipate.

During the threesix months ended MarchJune 31,30, 2026, there were no material changes to our contractual obligations and commitments from those described in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025.