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

Investing in our common stock involves a high degree of risk. You should carefully read and consider all of the risks described below, as well as the other information in this Form 10-K, including our financial statements and the related notes and the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and in other documents we file with the SEC when evaluating our business. The occurrence of any of the events or developments described below could harm our business, financial condition, results of operations and growth prospects. Unless otherwise indicated, references to our business being harmed in these risk factors will include harm to our business, reputation, financial condition, results of operations and future prospects. In such an event, the market price of our common stock could decline, and you may lose all or part of your investment. The risks described below are not intended to be exhaustive and are not the only risks that we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations and the market price of our common stock.

Since inception, we have incurred significant operating losses. Our net losses were $90.0$89.7 million and $78.6$90.0 million for the years ended December 31, 20242025 and December 31, 2023,2024, respectively. As of December 31, 2024,2025, we had an accumulated deficit of $271.5$361.1 million. To date, we have financed our operations primarily with the proceeds raised from the sale of our convertible preferred stock in private placements and common stock in our IPO and our equity offerings in early2024 2024,and 2025, described below. We have devoted substantially all of our financial resources and efforts to research and development activities, manufacturing, business planning, establishing and maintaining our intellectual property portfolio, acquiring and developing product and technology rights, hiring personnel, leasing premises and associated capital expenditures, raising capital, and providing general and administrative support for these operations. We are still in the early stages of development of our programs and havecurrently only advancedhave twoone product candidatescandidate advancing into clinical development. We expect to continue to incur significant expenses and operating losses for the foreseeable future. Our operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially if and as we:

establish manufacturing sources for our product candidates and secure supply chain capacity to provide sufficient quantities for preclinical and clinical development and commercial supply as well as other CMC activities which support registration, particularly as we scale for an anticipate Phase 3 pivotal trial and look to secure secondary source suppliers for our drug substance;

Even if we obtain regulatory approval of, and are successful in commercializing,commercializing oneour product candidate or moreany of ourfuture product candidates, we will continue to incur substantial research and development and other costs to develop and market additional product candidates. We may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. The size of our future net losses will depend, in part, on the rate of future growth of our expenses and our ability to generate revenue.

While we have completedinitiated oura Phase 1 clinical trial for PGN-EDO51 and initiated two Phase 2 clinical trials for PGN-EDO51 as well as an additional Phase 1 clinical trial for PGN-EDODM1 and more recently, a Phase 2 clinical trial for PGN-EDODM1, we expect that it will be many years, if ever, before we have a product candidate ready for commercialization. In December 2024, the FDA issued a clinical hold on the initiationAll of our Phaseother 2research CONNECT2programs, trialwhich ofare PGN-EDO51currently inpaused, DMDare nevertheless in the U.S.research Itor preclinical stage of development, and their risk of failure is unknowntherefore whetherparticularly we may be successful in resolving this hold. More recently, Health Canada has requested additional information from us to address safety concerns before any further dose escalation or enrollment of any additional participants at the current dose levels may proceed in our CONNECT1 study of PGN-EDO51. It is unknown whether Health Canada will allow us to dose escalate or enroll additional participants in this study. Moreover, even if we are successful in removing the FDA clinical hold, it is unknown whether the FDA may require the conduct of additional preclinical studies or clinical trials beyond those which we had planned to conduct.high. To become and remain profitable, we must succeed in developing, obtaining the necessary regulatory approvals for and eventually commercializing a product or products that generate significant revenue. The ability to achieve this success will require us to be effective in a range of challenging activities, including:

If we are successful in obtaining regulatory approval to market one or more of our product candidates, our revenue will be dependent, in part, upon the size of the markets in the territories for which we gain regulatory approval, the accepted price for the product, the ability to obtain coverage and reimbursement, the nature of the competition in such market, and whether we own the commercial rights for that territory. If the number of our addressable patients is not as significant as we estimate, the indication approved by regulatory authorities is narrower than we expect, or the treatment population is narrowed by competition, physician choice or treatment guidelines, we may not generate significant revenue from sales of such products, even if approved.

We will need to raise substantial additional funding. If we are unable to raise capitalsubstantial additional funding when needed, we could be forced to delay, scale back or discontinue our product development programs or future commercialization efforts.

We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we identify, continue the research and development of, continue preclinical testing and initiate clinical trials of, arrange for the manufacturing of, and potentially seek marketing approval for any product candidates that successfully completes clinical testing. To date, we have only completed a Phase 1 clinical trial for our first product candidate, PGN-EDO51, initiated one additional Phase 1 clinical trial for PGN-EDODM1, two Phase 2 clinical trials for PGN-EDO51 and more recently, one Phase 2 clinical trial for PGN-EDODM1. The resolution of the clinical hold in the U.S. on the initiation of the Phase 2 CONNECT2 clinical trial of PGN-EDO51, assuming resolution is reached with the FDA, may require additional capital beyond that we had planned to allocate to this program, and the amount of such capital could be considerable. In addition,Further, if we obtain marketing approval for PGN-EDODM1 or any other product candidate, we expect to incur significant commercialization expenses related to product manufacturing, marketing, sales and distribution. Furthermore, we expect to continue to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed, on attractive terms or at all, we may be forced to delay, reduce or eliminate our research and development programs or future commercialization efforts.

As of December 31, 2024,2025, we had cash, cash equivalents, and marketable securities of $120.2$148.5 million. Prior to our IPO in May 2022, we raised aggregate gross proceeds of $133.5 million from the private placement of convertible preferred stock. We raised aggregate gross proceeds of $122.9 million from our IPO. Subsequent to our IPO, in February 2024 we received net proceeds from our ATM program and 2024 Offering, after deducting underwriters' fees and costs of the offerings, of $86.3 million. In September 2025, we completed a public offering, or the 2025 Offering, which resulted in net proceeds of $107.6 million after deducting underwriters' fees and offering expenses.

the scope, progress, including continued momentum of enrollment in our FREEDOM2 trial, costs and results of preclinical and clinical development for ourPGN-EDODM1, productincluding candidatesthe nature and size of a Phase 3 pivotal trial, and any additional product candidates we may develop or any new indications we may pursue;

the scope, costs, timing and outcome of regulatory review of our product candidatesPGN-EDODM1 and any additional product candidates we may develop or any new indications we may pursue;

the revenue, if any, received from commercial sales of our clinical stage product candidatescandidate if marketing approval is received;

IdentifyingDeveloping our lead product candidate PGN-EDODM1, identifying other potential product candidates and conducting preclinical testing and clinical trials are time-consuming, expensive and uncertain processes requiring years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve product sales. In addition, even if we successfully develop product candidates and those are approved, we may not achieve commercial success. Our commercial revenues, if any, may not be sufficient to sustain our operations. 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.

Any additional fundraising efforts may divert our management from their day-to-day activities, which may adversely affect our operations. We cannot be certain that additional funding will be available on acceptable terms, when needed or at all. We have no committed source of additional capital and, if we are unable to raise additional capital in sufficient amounts, when needed or on terms acceptable to us, we may be required to significantly curtail, delay or discontinue one or more of our research or development programsprograms, including PGN-EDODM1 or the commercialization of any such product candidate, or be unable to expand our operations or otherwise capitalize on our business opportunities, as desired, and we may be required to initiate steps to cease operations, which could materially affect our business, financial condition and results of operations. We could be required to seek collaborators for product candidates at an earlier stage than otherwise would be desirable or on terms that are less favorable than might otherwise be available or relinquish or license on unfavorable terms our rights to product candidates in markets where we otherwise would seek to pursue development or commercialization ourselves. Any of the above events could significantly harm our business, prospects, financial condition and results of operations and cause the price of our common stock to decline.

We commenced operations in 2018, have no products approved for commercial sale and have not generated any revenue from product sales. To date, our operations have been limited to organizing and staffing our company, business planning, executing collaborations, raising capital, licensing, conducting research activities, conducting preclinical studies of our programs and clinical trials of our product candidates, manufacturing drug substance and drug product for our clinical programs, filing and prosecuting patent applications and providing general and administrative support for these operations. OneWe ofhave our product candidates, PGN-EDO51, completedinitiated a Phase 1 clinical trial and we have initiated one additional Phase 1 clinical trial for PGN-EDODM1 and two Phase 2 clinical trials for PGN-EDO51 and more recently, a Phase 2 clinical trial for PGN-EDODM1. In December 2024, the FDA issued a clinical hold on the initiation of our Phase 2 CONNECT2 trial of PGN-EDO51 in DMD in the U.S. It is unknown whether we may be successful in resolving this hold. Moreover, even if we are successful in removing the hold, it is unknown whether the FDA may require the conduct of additional preclinical studies or clinical trials beyond those which we had planned to conduct. More recently, Health Canada has requested additional information from us to address safety concerns before any further dose escalation or enrollment of any additional participants at the current dose levels may proceed in our CONNECT1 Phase 2 study of PGN-EDO51 in DMD. It is unknown whether Health Canada will allow us to dose escalate or enroll additional participants in this study.  All of our other research programs are stillpaused and, nevertheless, are in the research or preclinical stage of development, and their risk of failure is high. We have not yet demonstrated our ability to successfully complete clinical trials consistently, obtain marketing approvals, manufacture product on a commercial scale or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history or a history of successfully developing and commercializing products Our limited operating history may make it difficult to evaluate our technology and industry and predict our future performance. Our limited history as an operating company makes any assessment of our future success or viability subject to significant uncertainty. We will encounter risks and difficulties frequently experienced by early-stage companies in rapidly evolving fields. If we do not address these risks successfully, our business will suffer.

We are early in our development efforts.efforts, Wehaving haveconducted only completed atwo Phase 1 and three Phase 2 clinical trialtrials forsince our lead product candidate and initiated several additional clinical trials,inception and as a result it will be years before we commercialize a product candidate, if ever. If we are unable to advance our product candidates through preclinical studies and clinical trials, obtain marketing approval and ultimately commercialize them, or experience significant delays in doing so, our business will be materially harmed.

We are evaluatingprimarily additionalfocusing productour candidatesefforts inon preclinicalthe studies,clinical butdevelopment of PGN-EDODM1 and, accordingly, have not completed IND- or CTA-enabling activities for any of our other product candidates or advanced any of our otheradditional product candidates into clinical trials. Our ability to generate product revenue, which we do not expect will occur for many years, if ever, will depend heavily on the successful clinical development and eventual commercialization of our product candidates, which may never occur. We currently generate no revenue from sales of any product, and we may never be able to develop or commercialize a marketable product.

Commencing clinical trials in the U.S. is subject to authorization by the FDA of an IND and finalizing the trial design based on discussions with the FDA and other regulatory authorities. In the event that the FDA requires us to complete additional preclinical studies, or we are required to satisfy other FDA or other regulator requests prior to commencing clinical trials, the start of our clinical trials may be delayed. AsFor noted above, in December 2024, we announced that FDA had placed a clinical hold on the initiation of our planned Phase 2 CONNECT2 trial in the U.S. In addition, previously,instance, in May 2023, we announced that FDA had placed a clinical hold on our planned Phase 1 FREEDOM clinical trial of PGN-EDODM1 in the U.S. We submitted a response to the FDA and in October 2023, we announced that the FDA had lifted the clinical hold, allowing us to initiate FREEDOM in the U.S. EvenHowever, afterwe initiatingrecently received notice of a partial clinical hold from the FDA based on previously submitted preclinical pharmacology and toxicology studies. As part of our ongoing dialogue with the FDA, we are submitting additional analyses, including the recently unblinded Phase 1 FREEDOM data, and are committed to working with the FDA to address their questions as quickly as possible. We may not be able to resolve the issues related to such partial clinical hold in a timely manner, or at all, which may negatively impact the PGN-EDODM1 program, including the FREEDOM2 enrollment timelines. Furthermore, in the U.S.,future, the FDA or other regulatory authorities could disagree that we have satisfied their requirements to commence any clinical trial, including our FREEDOM2 study of PGN-EDODM1, or disagree with or change their position on the acceptability of our trial design or the clinical endpoints selected, which may require us to complete additional preclinical studies or clinical trials or impose stricter approval conditions than we currently expect. There are equivalent processes and risks applicable to CTAs in other countries, including Canada and countries in Europe. Moreover, regulatory authorities in other countries could request that we pause dosing or further enrollment in one or more of our ongoing studies based in whole or in part on a clinical hold or partial clinical hold in the U.S.

successful initiation, enrollment and completion of clinical trials, including under the FDA’s Good Clinical Practice, or GCP, GLP,Good Laboratory Practice, and any additional regulatory requirements from foreign regulatory authorities;

Our lead product candidatescandidate areis currently in clinical-stage development, while ourother otherpast product candidatescandidate areprograms stillwere in the research or preclinical stage of developmentdevelopment. andThus, our approach to treating muscle disease is unproven.unproven; Ourfor example past efficacy and safety results observed in the PGN-EDODM1 program may not result in a favorable safety profile or efficacy results as future clinical studies readout. In the future, our research programs may fail to identify potential product candidates for clinical development for a number of reasons. Our research methodology may be unsuccessful in identifying potential product candidates and our potential product candidates may be shown to have harmful side effects in preclinical in vitro experiments or in vivo animal model studies, or in future clinical studies. In addition, our potential product candidates may not show promising signals of therapeutic effect in such experiments or studiesstudies, as was the case with PGN-EDO51, or they may have other characteristics that may make the product candidates impractical to manufacture, unmarketable or unlikely to receive marketing approval. Further, because all of our development programs are based on our EDO platform, adverse developments with respect to one of our programs may have a significant adverse impact on the actual or perceived likelihood of success and value of our other programs. In addition, we may be negatively impacted by the decision of other companies to discontinue development of products using technology similar to our technology. For example, recently,during 2024, Sarepta Therapeutics, Inc., or Sarepta, announced that it was discontinuing its SRP-5051 peptide-linked PMOphosphorodiamidate morpholino, or PMO, development program, based on the risk-benefit of the program, including some patients experiencing hypomagnesemia even after treatment with SRP-5051 was discontinued, feedback from the FDA, and the evolving therapeutic landscape for DMD.

We have advanced our first two product candidates, PGN-EDO51 and PGN-EDODM1, into the clinic, and have completed a Phase 1 trial of PGN-EDO51 in HVs.healthy volunteers. However, the positive results we have observed in our preclinical studies and in the completed Phase 1 trial of PGN-EDO51 were not repeated at the same level in our CONNECT1 Phase 2 clinical trials, and we decided to discontinue development of PGN-EDO51. Accordingly, the results observed in our preclinical and Phase 1 clinical studies of PGN-EDODM1 may not be repeated in futureour ongoing Phase 2 clinical trials,study. including in patients with DMD amenable to an exon-51 skipping approach, andMoreover, regulatory authorities may disagree with the interpretation of data from our trials.

Although we are advancingcontinuing to focus the majority of our initialefforts programson the advancement of our program in DMD and DM1, our EDO platform may fail to yield additional product candidates for clinical development for a number of reasons, including those discussed in these risk factors. In addition:

The risk of failure in developing product candidates is high. It is impossible to predict when or if any product candidate would prove effective or safe in humans or will receive regulatory approval. Before obtaining marketing approval from regulatory authorities for the sale of any product candidate, we must complete preclinical development, obtain regulatory clearance to commence clinical trials, and then conduct extensive clinical trials to demonstrate the safety and efficacy of product candidates in humans. To date, we have only completedinitiated a Phase 1 clinical trial of PGN-EDO51 and initiated an additional Phase 1 clinical trial offor PGN-EDODM1, two Phase 2 clinical trials of PGN-EDO51 and more recently, a Phase 2 clinical trial offor PGN-EDODM1.

Clinical trials may fail to demonstrate that our product candidates are safe for humans and effective for indicated uses, and earlier results, both preclinical and clinical, may not be indicative of future clinical trial results. For example, in the case of PGN-EDO51, our product candidate for DMD, based on the levels of dystrophin protein measured in the 10 mg/kg cohort of CONNECT1, despite a favorable emerging safety profile, we decided to voluntarily discontinue development of PGN-EDO51 and are working to complete the wind-down of DMD-related research and development activities, including our research efforts in DMD relating to exons 44, 45 and 53. Even if theour clinical trials are successful, changes in marketing approval policies during the development period, changes in or the enactment or promulgation of additional statutes, regulations or guidance, varying interpretations of clinical data or changes in regulatory review for each submitted product application may cause delays in the approval or rejection of an application.

Before we can commence clinical trials for a product candidate, we must complete extensive preclinical testing and studies that support clearance of our INDs, CTAs and other similar regulatory filings. We cannot be certain if the outcome of our preclinical studies and clinical trials will ultimately support further development of our product candidatescandidates, as was the case with PGN-EDO51 or future programs, or future regulatory approval and commercialization. Although we have completed a Phase 1 study of our lead product candidate, PGN-EDO51, initiated two Phase 2 studies of PGN-EDO51 and initiated an additional Phase 1 and a Phase 2 clinical trial of our second candidate, PGN-EDODM1, we cannot be certain of the completion or outcome of our preclinical testing and studies for PGN-EDODM1 or any of our other product candidates and cannot predict whether the FDA, European Medicines Agency, or EMA, or comparable foreign regulatory authorities will accept our proposed clinical programsprogram for PGN-EDO51 or PGN-EDODM1, or whether the outcome of our preclinical testing and studies will ultimately support the further development of ourPGN-EODM1 or any other product candidates. For example, Health Canada has recently requested additional information from us to address safety concerns before any further dose escalation or enrollment of any additional participants at the current dose levels may proceed in our Phase 2 CONNECT1 study of PGN-EDO51 in DMD. It is unknown whether Health Canada will allow us to dose escalate or enroll additional participants in this study. In addition, in December 2024, the FDA issued a clinical hold on the initiation of our Phase 2 CONNECT2 trial of PGN-EDO51 in DMD planned to be initiated in the U.S. It is unknown whethercandidates we may be successful in resolving this hold. Moreover, even if we are successful in removing the hold, it is unknown whether the FDA may require the conduct of additional preclinical studies or clinical trials beyond those which we are conducting or plan to conduct.develop. Conducting preclinical testing is a lengthy, time-consuming and expensive process. The length of time may vary substantially according to the type, complexity and novelty of the program, and often can be several years or more per program. In addition, the progress and timing of our preclinical studies, including pharmacology and toxicology studies, may be impacted by the limited supply of NHPs needed for such studies. As a result, we cannot be sure that we will be able to submit INDs, CTAs and other similar regulatory filings for our programs on the timelines we expect, if at all, and we cannot be sure that submission of such regulatory filings will result in the FDA, EMAEuropean Medicines Agency, or EMA, or comparable foreign regulatory authorities allowing clinical trials to begin, including in the case of our CONNECT2 clinical study for PGN-EDO51 and our FREEDOM2 clinical study for PGN-EDODM1. For example, we recently received notice of a partial clinical hold from the FDA based on previously submitted preclinical pharmacology and toxicology studies. Furthermore, in May 2023, we announced that we received a clinical hold notice from the FDA regarding our IND application to initiate our Phase 1 FREEDOM study, and in June 2023, we provided an update on our plans with respect to this program. In October 2023, we announced that the FDA lifted the clinical hold on our Phase 1 FREEDOM study, allowing this study to proceed in the U.S.

delays in reaching agreement on acceptable terms with prospective clinical research organizations, or CROs,CROs and clinical trial sites;

delays in opening clinical trial sites or obtaining required institutional review board, or IRB, or independent ethics committee approval, or the equivalent review groups for sites outside the U.S., at each clinical trial site;

You should read the following discussion and analysis of our financial condition and results of operations together with our financial statements and the related notes included elsewhere in this Form 10-K. Some of the information contained in this discussion and analysis or set forth elsewhere in this Form 10-K, including information with respect to our plans, strategies, objectives, expectations and intentions for our business and related financing, includes forward-looking statements that involve risks and uncertainties. As a result of many factors, including those factors set forth in the “Risk Factors” section of this Form 10-K, our actual results could differ materially from the results described in or implied by these forward-looking statements. Please also see the section titled “Special Note Regarding Forward-Looking Statements.”

PepGen Inc., also referred to as “PepGen,” “we,” “our” or “us”, is a clinical-stage biotechnology company advancing the next-generation of oligonucleotide therapies with the goal of transforming the treatment of severe neuromuscular and neurological diseases. Our proprietary EDOEnhanced Delivery Oligonucleotide, or EDO, platform is founded on over a decade of research and development and leverages CPPscell-penetrating peptides, or CPPs, to improve the uptake and activity of conjugated oligonucleotide therapeutics. Using these EDO peptides, weour aregoal generatingis to develop a research and development pipeline of oligonucleotide therapeutic candidates that are designed to target the root cause of serious diseases.

We are also developing PGN-EDODM1 for the treatment of DM1 and are utilizing what we believe to be a unique mechanism of action and a different delivery approach compared to other approaches in more advanced stages of clinical development. We have conducted extensive preclinical studies of our product candidate, and these preclinical data form the basis of our clinical development plan for PGN-EDODM1. Our clinical development program for PGN-EDODM1 includes twothree studies, FREEDOM-DM1, or FREEDOM, a multinational, randomized, double-blind, placebo-controlled Phase 1 SADsingle ascending dose, or SAD, study, andFREEDOM2-DM1, or FREEDOM2, a multinational, randomized, double blind, placebo-controlled Phase 2 MAD study.study and FREEDOM-OLE, which is an open label extension study open to participants who meet its eligibility criteria and have completed either the FREEDOM or FREEDOM2 studies. In the FREEDOM study, we are enrolling adult participants with DM1 in multiple geographies including the U.S., U.K. and Canada, to evaluate the safety and tolerability of PGN-EDODM1, as well as oligonucleotide muscle concentrations, splicing correction and functional outcome measures at day 28 and at week 16 following a single dose of PGN-EDODM1. On February 24, 2025, we reported initial data from the 5 mg/kg and 10 mg/kg dose cohorts in this study.study where PGN-EDODM1 was observed to have a favorable emerging safety profile and robust splicing correction in a dose-dependent manner in the 5 and 10 mg/kg dose cohorts. WeAdditionally, expecton toSeptember report24, data2025, we reported topline results from the 15 mg/kg cohort ofin the FREEDOM study of PGN-EDODM1, demonstrating a mean splicing correction of 53.7% following a single 15 mg/kg dose, noting that PGN-EDOM1 was generally well tolerated at this dose, with all drug-related adverse events mild or moderate in severity. Based on the positive splicing correction observed in the secondFREEDOM halftrial and the totality of 2025.the blinded safety data to date, we have decided to conclude dose escalation in the FREEDOM trial with the 15 mg/kg cohort.

The safety data from the ongoing FREEDOM study has informed the design of FREEDOM2, which ishas received regulatory clearance in Canada, the United Kingdom, South Korea, Australia, and New Zealand and we are currently openenrolling patients in Canada and the U.K. We alsorecently planreceived tonotice openthat the FDA has placed a partial clinical hold on the FREEDOM2 study otherbased geographies,on previously submitted preclinical pharmacology and toxicology studies. The partial clinical hold did not cite any questions regarding the blinded clinical data from the FREEDOM Phase 1 study previously submitted to the FDA in order to initiate the FREEDOM2 study in the U.S. As part of our ongoing dialogue with the FDA, we are submitting additional analyses, including the U.S.,recently subjectunblinded FREEDOM data, and are preparing to regulatorywork authorizations.with the FDA to answer the questions as quickly as possible. FREEDOM2 is a Phase 2 randomized, double-blind, placebo-controlled MAD study of PGN-EDODM1 in DM1 patients. FREEDOM2 is designed to assess PGN-EDODM1’s safety and tolerability, splicing correction and functional outcome measures in DM1 patients. This study has concluded enrollment of the 5 mg/kg dose cohort and all participants have completed dosing. We expect to report data from this cohort at the 5 mg/kg cohortend of the FREEDOM2 study in the  first quarter of 2026. The study is currently dosing the 10 mg/kg dose cohort and we expect to report data from this cohort in the second half of 2026.

The FDA has granted both orphan drug designation and Fast Track designation for PGN-EDODM1 for the treatment of DM1.DM1 and the EMA has also granted orphan medicinal product designation to PGN-EDODM1.

Initial Public Offering, ATM Program, Follow-on OfferingOfferings and Liquidity

In May 2022, we closed our initial public offering, or IPO, in which we sold an aggregate of 9,000,000 shares of common stock at a public offering price of $12.00 per share for gross proceeds of $108.0 million. In connection with the IPO, we granted the underwriters a 30-day option to purchase 1,350,000 additional shares of common stock, which they exercised in part to purchase 1,238,951 additional shares of common stock for gross proceeds of $14.9 million. We received approximately $122.9 million in gross proceeds and $110.2 million in net proceeds in the IPO, after deducting underwriters’ fees and offering expenses.

On February 5, 2024, we issued and sold 1,000,000 shares of common stock shares at a purchase price of $10.00 per share under our at-the-market offering program, or ATM program, pursuant to thean At-the-Market Equity Offering Sales AgreementAgreement, or Sales Agreement, with Stifel, Nicolaus & Company, Incorporated, or Stifel, resulting in net proceeds of $9.9 million. On February 9, 2024, we issued and sold 7,530,000 shares of common stock at a purchase price of $10.635 per share, which was the closing sale price of our common stock on the Nasdaq Global Select Market on February 6, 2024, in an underwritten follow-on offering, or the Follow-on2024 Offering. The Follow-on2024 Offering resulted in net proceeds of $76.4 million after deducting underwriters' fees of $3.7 million. Net proceeds from the ATM program and Follow-on2024 Offering, after deducting underwriters’ fees and costs of the offerings, were $86.3 million.

Since our inception, we have not generated any revenue from product sales or other sources and have incurred significant operating losses and negative cash flows from our operations. Our primary uses of cash to date have been to fund our research and development activities, business planning, establishing and maintaining our intellectual property portfolio, acquiring and developing product and technology rights, hiring personnel, leasing premises and associated capital expenditures, raising capital, and providing general and administrative support for these operations. To date, we have funded our operations primarily through private placements of our convertible preferred stock and proceeds from our IPO, the ATM programprogram, the 2024 Offering, and the Follow-on2025 Offering.

We have incurred operating losses in each year since our inception. Our net losses were $90.0$89.7 million and $78.6$90.0 million for the years ended December 31, 20242025 and December 31, 2023,2024, respectively. As of December 31, 2024,2025, we had cash, cash equivalents, and marketable securities of $120.2$148.5 million. As of December 31, 2024,2025, we had an accumulated deficit of $271.5$361.1 million. WeNotwithstanding our decision to cease our research and development efforts in DMD, which we announced on May 28, 2025, we expect our expenses and operating losses will continue as we conduct our ongoing preclinical studies and current and planned clinical trials,trials of PGN-EDODM1, continue our research and development activities, utilize third parties to manufacture our product candidates and related raw materials, hire additional personnel, protect our intellectual property and incur additional costs associated with being a public company, including audit, legal, regulatory, and tax-related services associated with maintaining compliance with an exchange listing and SEC requirements, director and officer insurance premiums, and investor relations costs. In addition, we have several development, regulatory and commercial milestone payment obligations under our licensing arrangements. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies, current and planned clinical trials, manufacturing campaigns and our expenditures on other research and development activities.

Based on our currently planned operations, weWe believe that our existing cash, cash equivalents and marketable securities will be sufficient to fund our currently planned operations for at least 12 months frominto the datesecond half of the filing of this 10-K.2027. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which will not be for at least the next several years, if ever. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, until such time as we can generate significant revenue from sales of our product candidates, if ever, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, including potential collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such other arrangements when needed would have a negative impact on our financial condition and could force us to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

external expenses, including expenses incurred under arrangements with third parties, such as clinical research organizations, or CROs, contract development manufacturing organizations, or CDMOs, consultants and our scientific advisors;

The following table (in thousands) summarizes our research and development expenses for the years ended December 31, 20242025 and December 31, 2023.2024. The direct external development program expenses reflect external costs attributable to our clinical development candidates and preclinical candidates selected for further development. Our internal resources, personnel and infrastructure are not directly tied to any one research or drug discovery program and are deployed across multiple programs. As such, we do not track internal expenses on a program-specific basisbasis.

We expect that our research and development expenses will increase in 2025, as comparedcontinue to 2024, as we conduct our ongoing Phase 2 clinical trialstrial forof our investigational drug candidate, PGN-EDODM1. We have decided to conclude dose escalation in the FREEDOM trial with the 15 mg/kg cohort, based on the positive splicing correction observed and the totality of the blinded safety data to date. As stated above, on May 28, 2025, we announced that we have decided to voluntarily discontinue development of PGN-EDO51 and ourare ongoingworking Phaseto 1complete andthe Phase 2 clinical trialswind-down of PGN-EDODM1. We also continue to increase ourDMD-related research and development headcount to support these programs.activities. Research and development expenses for our lead programsprogram can be variable quarter-over-quarter due to the timing of manufacturing campaigns, which are accounted for under the percentage of completion method. The process of conducting preclinical studies and clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for anyour ofremaining ourclinical stage product candidates.candidate or any new product candidates we develop.

The timelines and costs associated with research and development activities are uncertain and can vary significantly for eachour product candidate and development program due to the inherently unpredictable nature of preclinical and clinical development. We anticipatepreviously weannounced willour decision to focus our development efforts on PGN-EDODM1, and to cease development of our DMD-related programs, and may make further determinations as to which programs in our research and development pipeline to pursue and how much funding to direct to each program on an ongoing basis in response to preclinical and clinical results, regulatory developments, and ongoing assessments as to each program’s commercial potential.program. We will need to raise substantial additional capital in the future.

the status of clinical trials, the timing and costs, if any, associated with resolving aclinical or partial clinical hold,holds, animal and other preclinical studies and IND- or clinical trial application, or CTA-enabling studies;

We anticipate that our general and administrative expenses will increase in 2025 as compared to 2024 primarily due to personnel costs, including stock-based compensation expense. Other general and administrative expenses will remain consistent to support our public company operating expenses associated with audit, legal, regulatory, and tax-related services associated with maintaining compliance with our exchange listing and SEC requirements, director and officer insurance premiums, and investor relations.

We record tax expense for state taxes on interest income generated from the Company's cash equivalents and marketable securities. We recognized a tax benefit for the year ended December 31, 2024 due to the derecognition of an unrecognized tax benefit of $0.7 million upon the dissolution of our U.K.-based entity, PepGen Limited on December 10, 2024. Additionally, we recorded $0.1 million in state taxes on interest income generated from the Company's cash equivalents and marketable securities. We have not recorded a U.S. provision for federal or state income taxes as we have no revenue and have incurred losses since inception.

Other income (expense), net was income of $4.0 million for the year ended December 31, 2025, compared to income of $7.1 million for the year ended December 31, 2024, compared to income of $6.2 million for the year ended December 31, 2023.2024. The increasedecrease was primarily driven by interestlower earnedcash frombalances in our money market fund accounts and U.S. treasury holdings.holdings prior to the 2025 Financing.

Income tax expense was $0.1 million for the year ended December 31, 2025 for state taxes on interest income generated from the Company's cash equivalents and marketable securities. Income tax benefit was a net benefit of $0.6 million for the year ended December 31, 2024 related the derecognition of an unrecognized tax benefit of $0.7 million upon the dissolution of our U.K.-based entity, PepGen Limited in December 2024. This is partially offset by $0.1 million in state taxes on interest income generated from the Company's cash equivalents and marketable securities. Income tax expense was $0.1 million for the year ended December 31, 2023.

FromSince our inception in January 2018 through December 31, 2024,2018, we have funded our operations primarily through the sale of our common stock and convertible preferred stock. We received aggregate gross proceeds of $163.9 million from these sales prior to our IPO. Additionally, in May 2022, we received gross proceeds from our IPO of $122.9 million.

On February 9, 2024, we issued and sold 7,530,000 shares of common stock in the Follow-on2024 Offering at a purchase price of $10.635 per share, resulting in net proceeds of $76.4 million after deducting underwriters’ fees and offering costs of $3.7 million.

As of December 31, 2024,2025, we had cash, cash equivalents, and marketable securities of $120.2$148.5 million. Based on our currently planned operations, weWe believe that our existing cash, cash equivalents, and marketable securities will be sufficient to fund our currently planned operations for at least 12 months frominto the datesecond half of the filing of this 10-K.2027. However, our forecast of the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. We have based this estimate on assumptions that may prove to be wrong, and we could deplete our capital resources sooner than we expect. Additionally, the process of conducting preclinical studies and testing product candidates in clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain.

the scope, progress, costs and results of preclinical and clinical development for our product candidates,PGN-EDODM1, any additional product candidates we may develop and any new indications we may pursue;

the scope, costs, timing and outcome of regulatory review of our product candidates,PGN-EDODM1, any additional product candidates we may develop and any new indications we may pursue;

the associated costs in connection with any acquisition of in-licensed products, intellectual property and technologies; and the ongoing costs of operating as a public company.

For the year ended December 31, 2024,2025, net cash used in operating activities was $82.4$81.6 million resulting from our net loss of $90.0$89.7 million and by cash provided by changes in our operating assets and liabilities of $5.3$6.2 million partially offset by non-cash charges of $12.9$14.2 million. The net changes in our operating assets and liabilities were primarily due to ana increasedecrease in prepaids and other current assets of $1.3$1.1 million, a decrease in accrued expenses of $1.7$3.3 million, and a $3.0$3.1 million decrease in operating lease liabilities.liabilities, These changes were partially offset byand a $0.7$0.9 million increasedecrease in accounts payable. Non-cash charges included $11.5$10.6 million in stock-based compensation expense, $3.9$2.2 million of accretion of discounts on our marketable securities, net, $3.7 million of amortization and interest accretion on our operating lease, and $1.5$1.4 million in depreciation expense. Additionally, there was a non-cash adjustment of $0.7 million related to the impairment of unused lab equipment.

For the year ended December 31, 2023,2024, net cash used in operating activities was $69.0$82.4 million resulting from our net loss of $78.6$90.0 million partially offsetand by cash provided by changes in our operating assets and liabilities of $2.0$5.2 million andpartially offset by non-cash charges of $7.7$12.9 million. The net changes in our operating assets and liabilities were primarily due to an increase in accrued expenses of $1.4 million and an increase in prepaids and other current assets of $2.0$1.3 million.million, a decrease in accrued expenses of $1.7 million, and a $3.0 million decrease in operating lease liabilities. These increaseschanges were partially offset by a $1.2$0.7 million decreaseincrease in operatingaccounts lease liabilities related to cash paid towards tenant improvements on our new office and lab lease.payable. Non-cash charges included $7.0$11.5 million in stock-based compensation expenseexpense, $3.9 million of accretion of discounts on our marketable securities, net, $3.7 million of amortization and $1.2interest accretion on our operating lease, and $1.5 million in depreciation expense.

Net cash provided by financing activities was $88.7$108.0 million for the year ended December 31, 2024,2025, resulting from $76.9$108.1 million in proceeds from the Follow-on2025 Offering,Offering $9.9and $0.3 million in proceeds from sales under the Sales Agreement, and $2.5 million fromof proceeds from the purchase of shares under employee equity plans, partially offset by $0.5$0.4 million in the payment of deferred offering costs.

Net cash usedprovided inby financing activities was $0.2$88.7 million for the year ended December 31, 2023,2024, whichresulting wasfrom primarily the result of $0.4$76.9 million in paymentsproceeds towardsfrom offeringthe costs2024 relatedOffering, to$9.9 ourmillion Formin S-3proceeds from sales under the Sales Agreement, and Sales Agreement filings in May and August 2023, respectively. These payments were partially offset by $0.3$2.5 million offrom proceeds from the purchase of shares under employee equity plans.plans, partially offset by $0.5 million in the payment of deferred offering costs.

While our significant accounting policies are more fully described in Note 2, “Summary of Significant Accounting Policies” to our consolidated financial statements appearing elsewhere in this Form 10-K, we believe that the following accounting policies are the most critical for fully understanding and evaluating our financial condition and results of operations.

The Black-Scholes option pricing model requires the use of subjective assumptions, including the risk-free interest rate, the expected stock price volatility, the expected term of stock options, the expected dividend yield, and the fair value of the underlying common stock on the date of grant. Changes in the assumptions can materially affect the fair value and ultimately how much stock-based compensation expense is recognized. Prior to our IPO, there was no public market for our common stock, and consequently, the estimated fair value of our common stock was determined by our board of directors as of the date of each stock option grant, with input from management, considering third-party valuations of our common stock as well as our board of directors’ assessment of additional objective and subjective factors that it believed were relevant and which may have changed from the date of the most recent third-party valuation through the date of the grant. These third-party valuations were performed in accordance with the guidance outlined in the American Institute of Certified Public Accountants’ Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation, or Practice Aid. The Practice Aid identifies various available methods for allocating the enterprise value across classes of series of capital stock in determining the fair value of our common stock at each valuation date. Since our IPO, we have determined the fair market value of our common stock using the closing price of our common stock as reported on the Nasdaq Global Select Market.

Since inception, we have incurred significant operating losses. Our net losses were $17.8$35.6 million and $30.2$53.3 million for the threesix months ended MarchJune 31,30, 2026 and MarchJune 31,30, 2025, respectively. As of MarchJune 31,30, 2026, we had an accumulated deficit of $378.9$396.7 million. To date, we have financed our operations primarily with the proceeds raised from the sale of our convertible preferred stock in private placements and common stock in our IPO and our equity offerings in 2024 and 2025, described below. We have devoted substantially all of our financial resources and efforts to research and development activities, manufacturing, business planning, establishing and maintaining our intellectual property portfolio, acquiring and developing product and technology rights, hiring personnel, leasing premises and associated capital expenditures, raising capital, and providing general and administrative support for these operations. We are still in the early stages of development of our programs and currently only have one product candidate advancing into clinical development. We expect to continue to incur significant expenses and operating losses for the foreseeable future. Our operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year. We anticipate that our expenses will increase substantially if and as we:

We expect our expenses to increase substantially in connection with our ongoing activities, particularly as we identify, continue the research and development of, continue preclinical testing and initiate clinical trials of, arrange for the manufacturing of, and potentially seek marketing approval for our product candidates that successfully complete clinical testing. To date, we have completed a Phase 1 clinical trial for PGN-EDODM1, and are conducting a Phase 2 clinical trial as well as an open label extension study for PGN-EDODM1. We will require significant additional funding to advance PGN-EDODM1 beyond the initial FREEDOM2 data readouts in 2026 to sustain our operations. We may be unable to raise additional funds, on favorable terms, if at all. If we are unable to raise such capital when needed, we will need to delay, reduce or terminate some or all planned activities to reduce costs and we may be required to initiate steps to cease operations and settle our liabilities. The failure to obtain sufficient additional funds on commercially acceptable terms to fund our operations and satisfy our obligations to creditors may have a material adverse effect on our business, results of operations and financial condition and jeopardize our ability to continue operations in the near-term.

As of MarchJune 31,30, 2026, we had cash, cash equivalents, and marketable securities of $132.3$117.2 million. Prior to our IPO in May 2022, we raised aggregate gross proceeds of $133.5 million from the private placement of convertible preferred stock. We raised aggregate gross proceeds of $122.9 million from our IPO. Subsequent to our IPO, in February 2024 we received net proceeds from our ATM program and 2024 Offering, after deducting underwriters' fees and costs of the offerings, of $86.3 million. In September 2025, we completed a follow-on public offering, or the 2025 Offering, which resulted in net proceeds of $107.6 million after deducting underwriters' fees and offering expenses. During the threesix months ended MarchJune 31,30, 2026, we sold 237,500 shares of common stock under the Sales Agreement resulting in net proceeds of $1.5 million.

We commenced operations in 2018, have no products approved for commercial sale and have not generated any revenue from product sales. To date, our operations have been limited to organizing and staffing our company, business planning, executing collaborations, raising capital, licensing, conducting research activities, conducting preclinical studies of our programs and clinical trials of our product candidates, manufacturing drug substance and drug product for our clinical programs, filing and prosecuting patent applications and providing general and administrative support for these operations. We have completed a Phase 1 clinical trial and are conducting a Phase 2 clinical trial as well as an open label extension for PGN-EDODM1. All of our other research programs are paused and, nevertheless, are in the research or preclinical stage of development, and their risk of failure is high. We have not yet demonstrated our ability to successfully complete clinical trials consistently, obtain marketing approvals, manufacture product on a commercial scale or arrange for a third party to do so on our behalf, or conduct sales, marketing and distribution activities necessary for successful product commercialization. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer operating history or a history of successfully developing and commercializing products.

We are early in our development efforts and have invested our research efforts to date in developing our EDO platform. Until May 2025, we had two product candidates in clinical trials —PGN-EDODM1 for DM1 and PGN-EDO51 for DMD. We have since voluntarily discontinued development of PGN-EDO51 and have substantially completed the wind-down of DMD-related research and development activities. We initiated a Phase 1 clinical trial, designated FREEDOM, for our product candidate, PGN-EDODM1, in December 2023 which was completed earlier this year. We are also conducting a Phase 2 clinical trial, FREEDOM2, in Canada, the U.K, South Korea, Australia and New Zealand.Zealand, which has concluded dosing of the 5 mg/kg cohort,cohort andwith seven of eight patients having completed enrollmentdosing ofin the 10 mg/kg cohort.

Commencing clinical trials in the U.S. is subject to authorization by the FDA of an IND and finalizing the trial design based on discussions with the FDA and other regulatory authorities. In the event that the FDA requires us to complete additional preclinical studies, or we are required to satisfy other FDA or other regulator requests prior to commencing clinical trials, the start of our clinical trials may be delayed. For instance, in May 2023, we announced that FDA had placed a clinical hold on our planned Phase 1 FREEDOM clinical trial of PGN-EDODM1 in the U.S. We submitted a response to the FDA and in October 2023, we announced that the FDA had lifted the clinical hold, allowing us to initiate FREEDOM in the U.S. However, in March 2026, we announced that we received notice of a partial clinical hold from the FDA based on previously submitted preclinical pharmacology and toxicology studies.studies As part of our ongoing dialogue with the FDA,and we submitted additional analyses, including the recently unblinded Phase 1 FREEDOM data, and are committedcontinue to workingwork with the FDA to address theirquestions questionsraised by the FDA as quickly as possible. We may not be able to resolve the issues related to such partial clinical hold in a timely manner, or at all, which may negatively impact the PGN-EDODM1 program, including the FREEDOM2 enrollment timelines. Furthermore, in the future, the FDA or other regulatory authorities could disagree that we have satisfied their requirements to commence any clinical trial, including our FREEDOM2 study of PGN-EDODM1, or disagree with or change their position on the acceptability of our trial design or the clinical endpoints selected, which may require us to complete additional preclinical studies or clinical trials or impose stricter approval conditions than we currently expect. There are equivalent processes and risks applicable to CTAs in other countries, including Canada and countries in Europe. Moreover, regulatory authorities in other countries could request that we pause dosing or further enrollment in one or more of our ongoing studies based in whole or in part on a clinical hold or partial clinical hold in the U.S.

Commercialization of our product candidates will require preclinical and clinical development; regulatory approval; manufacturing supply, capacity and expertise; a commercial organization; and significant marketing efforts. The success of our current and future product candidates will depend on many factors, including the following:

Clinical trials may fail to demonstrate that our product candidates are safe for humans and effective for indicated uses, and earlier results, both preclinical and clinical, may not be indicative of future clinical trial results. For example, in the case of PGN-EDO51, our product candidate for DMD, based on the levels of dystrophin protein measured in the 10 mg/kg cohort of CONNECT1, despite a favorable emerging safety profile, we decided to voluntarily discontinue development of PGN-EDO51 and arehave workingsubstantially to completecompleted the wind-down of DMD-related research and development activities, including our research efforts in DMD relating to exons 44, 45 and 53. Even if our clinical trials are successful, changes in marketing approval policies during the development period, changes in or the enactment or promulgation of additional statutes, regulations or guidance, varying interpretations of clinical data or changes in regulatory review for each submitted product application may cause delays in the approval or rejection of an application.

Before we can commence clinical trials for a product candidate, we must complete extensive preclinical testing and studies that support clearance of our INDs, CTAs and other similar regulatory filings. We cannot be certain if the outcome of our preclinical studies and clinical trials will ultimately support further development of our product candidates, as was the case with PGN-EDO51 or future programs, or future regulatory approval and commercialization. Although we have completed a Phase 1 trial and are conducting a Phase 2 clinical trial of our second candidate, PGN-EDODM1, we cannot be certain of the outcome of our preclinical testing, and clinical studies for PGN-EDODM1 or any of our other product candidates and cannot predict whether the FDA, or comparable foreign regulatory authorities will accept our proposed clinical program for PGN-EDODM1, or whether the outcome of our preclinical testing and clinical studies will ultimately support the further development of PGN-EODM1 or any other product candidates we may develop. Conducting preclinical testing is a lengthy, time-consuming and expensive process. The length of time may vary substantially according to the type, complexity and novelty of the program, and often can be several years or more per program. In addition, the progress and timing of our preclinical studies, including pharmacology and toxicology studies, may be impacted by the limited supply of NHPs needed for such studies. As a result, we cannot be sure that we will be able to submit INDs, CTAs and other similar regulatory filings for our programs on the timelines we expect, if at all, and we cannot be sure that submission of such regulatory filings will result in the FDA, competent authorities of the EU member states, or comparable foreign regulatory authorities allowing clinical trials to begin, including in the case of our FREEDOM2 clinical study for PGN-EDODM1. For example, in March 2026, we announced that we received notice of a partial clinical hold from the FDA based on previously submitted preclinical pharmacology and toxicology studies. As part of our ongoing dialogue with the FDA, we submitted additional analyses, including the recently unblinded Phase 1 FREEDOM data, andWe are committed to working with the FDA to address their questions; ashowever, quickly as possible. Wewe may not be able to resolve the issues related to such partial clinical hold in a timely manner, or at all, which may negatively impact the PGN-EDODM1 program, including the FREEDOM2 enrollment timelines. Furthermore, in May 2023, we announced that we received a clinical hold notice from the FDA regarding our IND application to initiate our Phase 1 FREEDOM study, and in June 2023, we provided an update on our plans with respect to this program. In October 2023, we announced that the FDA lifted the clinical hold on our Phase 1 FREEDOM study, allowing this study to proceed in the U.S.

We are in the early stages of our programs and have completed a Phase 1 clinical trial and are conducting a Phase 2 clinical trial for our PGN-EDODM1 product candidate. We reported data from three cohorts of our Phase 1 trial, and from one cohort of our Phase 2 trial of PGN-EDODM1, but we have not completed IND- or CTA-enabling activities or advanced any other product candidates (except PGN-EDO51) into clinical development. As a result, our belief in the capabilities of our platform is based on early research, preclinical studies, and early data from our early-stage studies and clinical trials. However, the results of preclinical studies may not be predictive of the results of later preclinical studies or clinical trials, and the results of any early-stage clinical trials may not be predictive of the results of later clinical trials. For example, since PGN-EDO51 did not achieve target dystrophin levels in the CONNECT1 trial, we made the decision to discontinue development of our DMD programs.

If PGN-EDODM1, or any of our future product candidates, cause undesirable side effects or have other unexpected adverse properties, such side effects or properties could delay or prevent the initiation or completion of clinical trialstrials, prejudice regulatory approval, limit the commercial potential of such candidate or result in significant negative consequences following any potential marketing approval.

For example, following the recent unblinding of the single-ascending dose portion of the FREEDOM trial, analysis of a kidney safety composite measure biomarker was conducted, and, at the 10 and 15 mg/kg dose levels, transient biomarkers associated with tubular insult were noted, as well as the observation of a DLT being identified at the 15 mg/kg dose level. Furthermore, we continue to observe transient increases in albuminuria in certain patients. Although these laboratory findings resolved without medical treatment or intervention and were not associated with clinical symptoms, the clinical significance of these findings is not yet fully understood. As we continue dose escalation and multi-dose administration in the FREEDOM2 study, with seven of eight patients having completed dosing doses in the 10 mg/kg cohort, we are monitoring safety results, including notingcontinuing to note transient or sustained increases in certain kidney function biomarkers, with a goal of determining the optimal dose in multi-dose cohorts in future clinical studies. Accordingly, we may observe additional renal effects, including more pronounced or persistent laboratory abnormalities, clinically symptomatic renal events, or other safety signals as the study continues. Given the stage of clinical development of PGN-EDODM1, there can be no assurance that PGN-EDODM1 will not cause undesirable side effects in patients with further dosing and dose escalation, including, for example, safety events similar to those observed in our studies with PGN-EDO51. If such events occur, we may be required to modify, suspend, or terminate clinical trials, reduce dosing, implement additional monitoring, or conduct additional preclinical studies, which could delay development, increase costs, or adversely affect the commercial prospects of PGN-EDODM1.

We conducted our first clinical trial in Canada, and we intend to continue to conduct one or more of our subsequent clinical trials for our product candidates outside the U.S., including our FREEDOM and FREEDOM2 clinical trials, each of which has or will have sites in multiple countries outside of the U.S. Currently, there are no U.S. sites opened in the FREEDOM2 trial as we await a determination from FDA with respectdue to the partial clinical hold of the FREEDOM2 trial in the U.S.U.S to begin site initiation.. Although the FDA may accept data from clinical trials conducted outside the U.S., acceptance of this data is subject to certain conditions imposed by the FDA. Where data from foreign clinical trials are intended to serve as the basis for marketing approval in the U.S., the FDA will not approve the application on the basis of foreign data alone unless those data are applicable to the U.S. population and U.S. medical practice; the studies were performed by clinical investigators of recognized competence; and the data are considered valid without the need for an on-site inspection by the FDA or, if the FDA considers such an inspection to be necessary, the FDA is able to validate the data through an on-site inspection or other appropriate means. For studies that are conducted only at sites outside of the U.S. and not subject to an IND, the FDA generally does not provide advance comment on the clinical protocols for the studies, and therefore there is an additional potential risk that the FDA could determine that the study design or protocol for a non-U.S. clinical trial was inadequate, and require us to conduct additional clinical trials. In addition, even where the foreign study data are not intended to serve as the sole basis for approval, the FDA will not accept the data as support for an application for marketing approval unless the study is well-designed and well-conducted in accordance with GCP and the FDA is able to validate the data from the study through an onsite inspection if deemed necessary. Many foreign regulatory authorities have similar approval requirements. There can be no assurance the FDA will accept data from clinical trials conducted outside of the U.S. If the FDA does not accept data from our clinical trials of our product candidates, we would likely need to conduct additional clinical trials, which would be costly and time consuming and delay or permanently halt our development of our product candidates. Additionally, recent policy proposals in the U.S., if enacted in the future, may make acceptance by the FDA or inclusion in a marketing application of foreign data more difficult or costly.

We rely, and expect to continue to rely, on third parties to conduct some or all aspects of our product manufacturing, research and preclinical and clinical testing, and these third parties may not perform satisfactorily. If we need to replace one or more of these third parties, our development plans may be significantly delayed and we may expend more funds thenthan currently planned.

Finally, in December 2025, the National Defense Authorization Act for Fiscal Year 2026, or the NDAA, was enacted, which includes Section 851, commonly referred to as the “BIOSECURE Act.” The BIOSECURE Act restricts U.S. government agencies from procuring biotechnology equipment or services from, or entering into contracts with, entities that use biotechnology equipment or services from, designated “biotechnology companies of concern,” or BCCs, and from expending federal loan or grant funds for such equipment or services. We currently rely on third-party contract manufacturing organizations and other vendors located outside the United States, including entitiesWuXi thatAppTec operatewhich operates in China,China and manufactures our active pharmaceutical ingredient, or API, for the manufacturer of certain clinical trial materials and the provision of certain development-related services.PGN-EDODM1. While none of our vendors are currently listed as a BCC, therein June 2026, WuXi AppTec was added to the Department of Defense’s Section 1260H list of Chinese military companies, which is aone riskof theytwo maystatutory pathways to BCC designation under the BIOSECURE Act; this means that WuXi AppTec is expected to be included in theOMB’s future,initial particularlyBCC withlist, respectdue tono ourlater Chinesethan vendors.December 2026. WuXi AppTec has publicly challenged its 1260H designation, and that challenge remains pending. If our current or future vendors with which we work are designated as BCCs in the future, or if our collaborators, customers, investors, or future commercial partners become subject to BIOSECURE-related restrictions as a result of their relationships with such vendors, we could be required to terminate or restructure existing arrangements, transition manufacturing or other services to alternative suppliers, or delay or suspend development activities, subject to a grace period of 5 years during which time a company could continue to work with such restricted vendor. AnyAlthough we currently have ongoing workstreams to secure a secondary source supplier of our API, any such transition could involve significant cost, operational complexity, regulatory risk, and delays, and alternative suppliers may not be available on acceptable terms or at all.

Many of the suppliers for components and materials used in our product candidates, including the manufacturer for active pharmaceutical ingredient and finishfinished product for PGN-EDODM1, are single-sourced. We cannot ensure that these suppliers or service providers will remain in business, have sufficient capacity or supply to meet our needs or that they will not be purchased by one of our competitors or another company that is not interested in continuing to work with us. Our use of single-source suppliers of raw materials, components, key processes, active pharmaceutical ingredients and finished goods could expose us to several risks, including disruptions in supply, price increases or late deliveries. There are, in general, relatively few alternative sources of supply for substitute components. These vendors may be unable or unwilling to meet our future demands for our clinical trials or commercial sales. Establishing additional or replacement suppliers for these components, materials and processes could take a substantial amount of time and it may be difficult to establish replacement suppliers who meet regulatory requirements. Any disruption in supply from any single-source supplier or service provider could lead to supply delays or interruptions which would damage our business, financial condition, results of operations and prospects.

Although we completed a Phase 1 clinical trial for PGN-EDO51 and havea, completed onea Phase 1 clinical trial,trial for PGN-EDODM1, and have twoa Phase 2 clinical trialstrial ongoing for PGN-EDODM1, we have not completed any additional clinical trials, and have limited experience as a company in preparing, submitting and prosecuting regulatory filings. In addition, we have had limited interactions with the FDA, the EMA and comparable foreign regulatory authorities and cannot be certain how many clinical trials of PGN-EDODM1, or any other product candidates will be required or how such trials should be designed. The FDA has previously provided feedback on our clinical trials for PGN-EDODM1, and we have addressed their feedback in our clinical trial designs.PGN-EDODM1. We may be unable to efficiently execute and complete necessary clinical trials for our product candidates in a way that leads to regulatory submission and approval of any of our product candidates, including potentially any accelerated approval. We may require more time and incur greater costs than our competitors and may not succeed in obtaining regulatory approvals of product candidates that we develop. Failure to commence or complete, or delays in, our current or planned clinical trials, could prevent us from or delay us in submitting NDAs for and commercializing our product candidates.

We plan to seek approval from the FDA or comparable foreign regulatory authorities, where applicable, under the accelerated approval pathways. We may fail to obtain approval under such accelerated approval pathways. Moreover, these pathways may not lead to a faster development, regulatory review or approval process and do not increase the likelihood that our product candidates will receive marketing approval.

Prior to seeking accelerated approval for PGN-EDODM1, we intend to seek feedback from the FDA or similar foreign regulatory authorities and will otherwise evaluate our ability to seek and receive accelerated approval. There can be no assurance that after our evaluation of the feedback and other factors we will decide to pursue or submit an NDA or similar application for accelerated approval or any other form of expedited development or review. Similarly, there can be no assurance that after subsequent FDA or similar foreign regulatory authorities feedback we will continue to pursue or apply for accelerated approval or any other form of expedited development or review, even if we initially decide to do so. Furthermore, if we decide to submit an application for accelerated approval or other expedited development or review, there can be no assurance that such submission or application will be accepted or that any expedited development or review will be granted on a timely basis, or at all.all, due, for example, to the fact that there may be newly approved therapeutic products on the market addressing DM1 at the time of submission of our application. The FDA or other comparable foreign regulatory authorities could also require us to conduct further studies prior to considering our application or granting approval of any type. A failure to obtain accelerated approval or any other form of expedited development or review for PGN-EDODM1 or any other product candidates would result in a longer time period to commercialization of such product candidate, would increase the cost of development of such product candidate, and would harm our competitive position in the marketplace.

The process of obtaining marketing approvals, both in the U.S. and abroad, is expensive, may take many years if additional clinical trials are required, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Of the large number of products in development, only a small percentage successfully complete the FDA, EMA or foreign regulatory approval processes and are commercialized. Even if our product candidates demonstrate safety and efficacy in clinical trials, the regulatory agencies may not complete their review processes in a timely manner, or we may not be able to obtain regulatory approval. Additional delays may result if an FDA Advisory Committee or other regulatory authority recommends non-approval or restrictions on approval. Changes in marketing approval policies during the development period, changes in or the enactment of additional statutes or regulations, or changes in regulatory review for each submitted product application, may cause delays in the approval or rejection of an application. In February 2026, the former FDA Commissioner publicly indicated that a single adequate and well-controlled pivotal clinical trial supported by confirmatory evidence willwould be the FDA’s default standard moving forward for novel products, rather than two such trials; this statement was not a formal agency action,action. In June 2026, FDA issued revised draft guidance clarifying how sponsors can rely on one scientifically rigorous adequate and well-controlled clinical investigation with confirmatory evidence to satisfy the scope,statutory implementationsubstantial evidence of effectiveness standard. Additionally, in July 2026, in response to congressional inquiries, FDA indicated that informal statements, issued through journals or means other than formal notice and durabilitycomment rule-making, are not reflective of thisofficial FDA policy positionand remainshould uncertain.not be interpreted as regulatory guidance. FDA retains broad discretion to require additional clinical data for any product candidate, including a second adequate and well-controlled clinical trial. The FDA, the EMA and comparable foreign regulatory authorities in other countries have substantial discretion in the approval process and may refuse to accept any application or may decide that our data is insufficient for approval and require additional preclinical, clinical or other studies. In addition, varying interpretations of the data obtained from preclinical and clinical testing could delay, limit or prevent marketing approval of a product candidate. Moreover, the U.S. Supreme Court’s July 2024 decision to overturn prior established case law giving deference to regulatory agencies’ interpretations of ambiguous statutory language has introduced uncertainty regarding the extent to which FDA’s regulations, policies, and decisions may become subject to increasing legal challenges, delays, and/or changes. If we experience delays in obtaining approval or if we fail to obtain approval of our product candidates, the commercial prospects for those product candidates may be harmed, and our ability to generate revenues will be materially impaired.

If the FDA determines that a product candidate offers a treatment for a serious or life-threatening condition and, if approved, the product would provide a significant improvement in safety or effectiveness, the FDA may designate the product candidate for priority review. A priority review designation means that the goal for the FDA to review and take action on ana marketing application for a new molecular entity is six months, rather than the standard review period of ten months. We may request priority review for our product candidates. The FDA has broad discretion with respect to whether or not to grant priority review status to a product candidate, so even if we believe a particular product candidate is eligible for such designation or status, the FDA may decide not to grant it. Moreover, a priority review designation does not necessarily result in an expedited regulatory review or approval process or necessarily confer any advantage with respect to approval compared to conventional FDA procedures. Receiving priority review from the FDA does not guarantee approval within the six-month review cycle or at all.

In September 2023, the FDA granted orphan drug designation to PGN-EDODM1 for the treatment of DM1. We may seek orphan drug designation for any other product candidates we develop; however, we may never receive such designations. Under the Orphan Drug Act, the FDA may designate a product as an orphan drug if it is a drug or biologic intended to treat a rare disease or condition, defined as a patient population of fewer than 200,000 in the U.S., or a patient population greater than 200,000 in the U.S. where there is no reasonable expectation that the cost of developing the drug will be recovered from sales in the U.S. Orphan drug designation must be requested before submitting an NDA. A similar regulatory scheme governs orphan products in the EU.

The FDA, the EMA or a comparable foreign regulatory authority may not approve our current product candidate or any new product candidates derived from our platform. However, if the FDA, EMA or comparable foreign regulatory authority approves any of our product candidates, the manufacturing processes, labeling, packaging, distribution, adverse event reporting, storage, advertising, promotion and record keeping for the product will be subject to extensive and ongoing regulatory requirements. These requirements include submissions of safety and other post-marketing information and reports, conformance with applicable product tracking and tracing requirements, establishment registration and listing, as well as continued compliance with cGMPs and GCPs for any clinical trials that we conduct post-approval. Any regulatory approvals that we receive for our product candidates may also be subject to limitations on the approved indicated uses for which the product may be marketed or to the conditions of approval, or contain requirements for potentially costly post-marketing studies, and surveillance to monitor the safety and efficacy of the product. Additionally, under FDORA, sponsors of approved drugs and biologics must provide six months’ notice to the FDA of any changes in marketing status, or for discontinuing or interrupting supply of certain drugs, including the withdrawal of a drug, and failure to do so could result in a letter citing such failure to comply and public posting of such letter and redacted company response which could damage the company’s reputation. Later discovery of previously unknown problems with a product, including adverse events of unanticipated severity or frequency, or with our third-party manufacturers or manufacturing processes, or failure to comply with regulatory requirements, may result in, among other things:

Disruptions at the FDA and other federal agencies, including substantial leadership departures, personnel cuts, and policy changes, may also slow the time necessary for proposed clinical studies to obtain clearance or new drugs to be reviewed and/or approved, which wouldcould harm our business. Changes and cuts in FDA staffing have been reported as resulting in delays in the FDA’s responsiveness or in its ability to review submissions or marketing applications, issue regulations or guidance, or implement or enforce regulatory requirements in a timely fashion or at all.

With the changecurrent in the U.S. presidential administration in 2025,administration, there have been numerous legislative and regulatory changes, and there continues to be substantial uncertainty as to the extent and manner in which the Trump administration will continue to modify or revise the requirements and policies of the FDA and other regulatory agencies with jurisdiction over our product candidates and any products for which we obtain approval. This uncertainty could present new challenges and/or opportunities as we navigate development and approval of our product candidates. Additionally, the administration could issue or promulgate executive orders, regulations, policies or guidance that adversely affect us or create a more challenging or costly environment in which to pursue the development of new therapeutic candidates. Also, state governments may seek to address or react to changes at the federal level with changes to their regulatory frameworks in a manner that could impact our operations.

We are exposed to the risk of fraud or other misconduct by our employees, consultants and partners, and in our clinical trials, our principal investigators. Misconduct by these parties could include intentional or unintentional failures to comply with FDA regulations or the regulations applicable in the EU and other jurisdictions, provide accurate information to the FDA, the European Commission and other regulatory authorities, comply with healthcare fraud and abuse laws and regulations in the U.S. and abroad, report financial information or data accurately, or disclose unauthorized activities to us. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Such misconduct also could involve the improper use of information obtained in the course of clinical trials or interactions with the FDA, the European Commission and other regulatory authorities, which could result in regulatory sanctions and cause serious harm to our reputation. It is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting us from government investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, financial condition, results of operations and prospects, including the imposition of significant fines or other sanctions.

We expect to face competition from existing products and product candidates in development for our programs. For our sole clinical-stage product candidate, PGN-EDODM1, there are currently no approved therapies to treat the underlying cause of the disease. Pipeline candidates currently in development to treat DM1 include several approaches that target DMPK RNA. These include AOC 1001, an antibody linked siRNA in Phase 3 clinical development by Avidity Biosciences, Inc., or Avidity, which has agreed to bebeen acquired by Novartis, subject to various closing conditionsNovartis; DYNE-101, an antibody conjugated antisense oligonucleotide in Phase 2 clinical development by Dyne, with an ongoing registrational expansion cohort reportedly intended to support a potential submission for accelerated approval in the U.S. and witha plansrecently by Dyne to initiate ainitiated confirmatory Phase 3 clinical trial of DYNE-101 in Q1 2026; VX-670, a peptide conjugated PMO in Phase 2 originally developed by Entrada Therapeutics, Inc., or Entrada, and Vertex; and ARO-DM1, a conjugated siRNA in Phase 1/2 clinical development by Sarepta, originally developed by Arrowhead Pharmaceuticals, Inc., or Arrowhead. There are additional approaches under development such as ATX-01, a microRNA that modulates expression of MBNL1 by Arthex Biotech S.L., that is in Phase 1/2a clinical development. Another small molecule, tideglusib, which is a GSK3-ß inhibitor is in clinical development by AMO for the congenital phenotype of DM1.

We will also compete more generally with other companies developing alternative scientific and technological approaches, including other companies working to develop conjugates with oligonucleotides for extra-hepatic delivery, including Alnylam Pharmaceuticals, Inc., Aro Biotherapeutics Co., Arrowhead, Avidity (which has agreed to bebeen acquired by Novartis), Dicerna Pharmaceuticals, Inc. (acquired by Novo Nordisk), Dyne, Entrada, Ionis Pharmaceuticals, Inc., PYC Therapeutics Limited and Sarepta, as well as gene therapy and gene editing approaches.

Factors that may inhibit our effortsefforts, or third-party efforts, to commercialize our products on our own include:

our inabilityability to recruit, train and retain adequate numbers of effective sales, marketing, coverage or reimbursement, customer service, medical affairs and other support personnel;

the inabilityability of sales personnel to educate adequate numbers of physicians on the benefits of any future products;

the inabilityability of reimbursement professionals to negotiate arrangements for formulary access, reimbursement and other acceptance by payors;

the inabilityability to price our productsfuture products, if approved, at a sufficient price point to ensure an adequate and attractive level of profitability;

In addition, our trade secrets may otherwise become known or be independently discovered by competitors or other third parties. Competitors or third parties could purchase our product candidates or our technology and attempt to replicate some or all of the competitive advantages we derive from our development efforts, willfully infringe our intellectual property rights, design around our intellectual property rights or develop their own competitive technologies that fall outside the scope of our intellectual property rights. If any of our trade secrets were to be lawfully obtained or independently developed by a competitor or other third party, we would have no right to prevent them, or those to whom they communicate such trade secrets, from using that technology or information to compete with us. If our trade secrets are not adequately protected so as to protect our market against competitors’ products, our business, financial condition, results of operations and prospects could be materially and adversely affected.

As of MarchJune 31,30, 2026, we had 5957 full-time employees. As our development progresses including possibly commencing a pivotal Phase 3 clinical study and related NDA filing for PGN-EDODM1, we expect to experience growth in the number of our employees and the scope of our operations, particularly in the areas of drug development, clinical, regulatory affairs and, if any product candidate receives marketing approval, sales, marketing, distribution and coverage and reimbursement capabilities. To manage our potential future growth, we must continue to implement and improve our managerial, operational and financial systems, and continue to recruit and train necessary qualified personnel and longer-term, may need to expand our facilities. Due to our limited financial resources and the limited experience of our management team in managing a company with such anticipated growth, we may not be able to effectively manage the expansion of our operations or recruit and train additional qualified personnel. The expansion of our operations may lead to significant costs and may divert our management and business development resources. Any inability to manage growth could delay the execution of our business plans or disrupt our operations.

Based upon our common stock outstanding as of MarchJune 31,30, 2026, our executive officers, directors, greater than five percent shareholders and their affiliates beneficially own approximately 46.5%47.7% of our outstanding common stock. As a result, if these stockholders were to choose to act together, they would be able to significantly influence all matters submitted to our stockholders for approval, as well as our management and affairs, even though some of these persons or entities may have interests that are different than those of yours. For example, these stockholders, if they choose to act together, could significantly influence the election of directors and approval of any merger, consolidation or sale of substantially all of our assets.

As a company that carries out extensive research and development activities, we sought to benefit from the U.K. research and development tax relief programs, being the Small and Medium-sized Enterprises R&D tax relief program, or SME Program, and, to the extent that our projects are grant funded or relate to work subcontracted to the company by third parties, the Research and Development Expenditure Credit program, or RDEC Program. Under the SME Program, we may be able to surrender the trading losses that arise from our qualifying research and development activities for a cash rebate of approximately 33.4% of the surrenderable losses. The majority of our research and development activities during 2021 were eligible for inclusion within these tax credit cash rebate claims. We may not be able to continue to claim payable research and development tax credits in the future if we cease to qualify as an SME, based on size criteria concerning employee headcount, turnover and gross assets or if we no longer conduct qualifying research and development activities through our wholly-owned subsidiary PepGen Limited. The U.K. Finance Act of 2021 introduced a cap on payable credit claims under the SME Program in excess of £20,000 with effect from April 2021 by reference to, broadly, three times the total PAYE and NICs liability of the company, subject to an exception which prevents the cap from applying. That exception requires the company to be creating, taking steps to create or managing intellectual property, as well as having qualifying research and development expenditure in respect of connected parties which does not exceed 15% of the total qualifying expenditure. If such exception does not apply, this could restrict the amount of credit that we are able to claim. For the threesix months ended MarchJune 31,30, 2026, our research and development tax credits from the U.K. government were not material as the intellectual property was transferred from our wholly-owned U.K. subsidiary, PepGen Limited, to the parent company, PepGen Inc. in January 2022.

The safety data from the FREEDOM study informed the design of FREEDOM2, which has received regulatory clearance in Canada, the United Kingdom, South Korea, Australia, and New Zealand and we are currently enrolling patients in Canada and the U.K. and other geographies.Zealand. The FREEDOM2 study remains on partial clinical hold in the U.S. and we continue to work with the FDA to address questions raised by the FDA as quickly as possible. FREEDOM2 is a Phase 2 randomized, double-blind, placebo-controlled MAD study of PGN-EDODM1 in DM1 patients. FREEDOM2 is designed to assess PGN-EDODM1’s safety and tolerability, splicing correction and functional outcome measures in DM1 patients. We recently reported topline results from the 5 mg/kg cohort in the FREEDOM2 study where PGN-EDODM1 was generally well-tolerated, with no serious adverse events (SAEs), all related treatment emergent adverse events (TEAEs) reported as mild, all non-related TEAEs reported as mild or moderate, and no signs of cumulative toxicity. Such results also demonstrated a mean splicing correction of 7.3%, compared to 6.8% in placebo-treated patients. However, excluding one outlier patient, patients showed a mean splicing correction of 22.9% as the outlier patient exhibited a worsening in splicing correction (70.8%), reducing the overall group mean to 7.3%. Middle finger vHOT in the treatment group in this cohort showed a positive trend of improvement versus a worsening observed in the placebo group with both returning to baseline at the last assessment. The FREEDOM2 study ishas currently dosing completed enrollment of the 10 mg/kg dose cohort with seven of eight patients having completed dosing, and we expect to report data from this cohort in November, 2026. Furthermore, based on the secondreview of available safety data from the 10 mg/kg dose cohort of the FREEEDOM2 study, an independent Data and Safety Monitoring Board, or DSMB, recommended advancing the FREEDOM2 trial into the third and highest dose cohort at 12.5 mg/kg; results from the 12.5 mg/kg cohort of FREEDOM2 are expected in the first half of 2026.2027. The DSMB also approved dose escalation in the open-label extension study, or OLE, from 5 mg/kg to 10 mg/kg dosing.

On February 5, 2024, we issued and sold 1,000,000 shares of common stock at a purchase price of $10.00 per share under our at-the-market offering program, or ATM program, pursuant to an At-the-Market Equity Offering Sales Agreement, or Sales Agreement, with Stifel, Nicolaus & Company, Incorporated, or Stifel, resulting in net proceeds of $9.9 million. On February 9, 2024, we issued and sold 7,530,000 shares of common stock at a purchase price of $10.635 per share, which was the closing sale price of our common stock on the Nasdaq Global Select Market on February 6, 2024, in an underwritten follow-on offering, or the 2024 Offering. The 2024 Offering resulted in net proceeds of $76.4 million after deducting underwriters' fees of $3.7 million. Net proceeds from the ATM program and 2024 Offering, after deducting underwriters’ fees and costs of the offerings, were $86.3 million. During the threesix months ended MarchJune 31,30, 2026, the Company sold 237,500 shares of common stock under the Sales Agreement resulting in net proceeds of $1.5 million.

We have incurred operating losses in each year since our inception. Our net losses were $17.8$35.6 million and $30.2$53.3 million for the threesix months ended MarchJune 31,30, 2026 and MarchJune 31,30, 2025, respectively. As of MarchJune 31,30, 2026, we had cash, cash equivalents, and marketable securities of $132.3$117.2 million. As of MarchJune 31,30, 2026, we had an accumulated deficit of $378.9$396.7 million. Notwithstanding our decision to cease our research and development efforts in DMD, which we announced on May 28, 2025, we expect our expenses and operating losses will continue as we conduct our ongoing preclinical studies and current and planned clinical trials of PGN-EDODM1, continue our research and development activities, utilize third parties to manufacture our product candidates and related raw materials, hire additional personnel, protect our intellectual property and incur additional costs associated with being a public company, including audit, legal, regulatory, and tax-related services associated with maintaining compliance with an exchange listing and SEC requirements, director and officer insurance premiums, and investor relations costs. In addition, we have several development, regulatory and commercial milestone payment obligations under our licensing arrangements. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies, current and planned clinical trials, manufacturing campaigns and our expenditures on other research and development activities.

We believe that our existing cash, cash equivalents and marketable securities will be sufficient to fund our currently planned operations into the secondfourth halfquarter of 2027. We do not expect to generate any revenues from product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our product candidates, which will not be for at least the next several years, if ever. If we obtain regulatory approval for any of our product candidates, we expect to incur significant commercialization expenses related to product sales, marketing, manufacturing and distribution. Accordingly, until such time as we can generate significant revenue from sales of our product candidates, if ever, we expect to finance our cash needs through equity offerings, debt financings or other capital sources, including potential collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. Our failure to raise capital or enter into such other arrangements when needed would have a negative impact on our financial condition and could force us to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

The following table (in thousands) summarizes our research and development expenses for the three and six months ended MarchJune 31,30, 2026 and MarchJune 31,30, 2025. The direct external development program expenses reflect external costs attributable to our clinical development candidates and preclinical candidates selected for further development. Our internal resources, personnel and infrastructure are not directly tied to any one research or drug discovery program and are deployed across multiple programs. As such, we do not track internal expenses on a program-specific basis.

The Phase 1 FREEDOM clinical trial of our investigational drug candidate, PGN-EDODM1PGN-EDODM1, has completed and we continue to conduct the ongoing Phase 2 FREEDOM2 and Open Label Extension clinical trial.trials. On May 28, 2025, we announced that we decided to voluntarily discontinue development of PGN-EDO51 and arehave workingrecently tosubstantially completecompleted the wind-down of DMD-related research and development activities. Research and development expenses for our lead program can be variable quarter-over-quarter due to the timing of manufacturing campaigns, which are accounted for under the percentage of completion method. The process of conducting preclinical studies and clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for our remaining clinical stage product candidate or any new product candidates we develop.

Interest income consists of interest earned on our moneycash market mutual fundsequivalents and short-termmarketable U.S. treasury holdings.securities.

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

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

General and administrative expenses remainedincreased flatby $0.9 million from $5.9$5.5 million for the three months ended MarchJune 31,30, 2025, to $5.9$6.4 million for the three months ended MarchJune 31,30, 2026. The increase was primarily driven by an increase of $0.7 million in personnel-related costs, including $0.6 million in stock-based compensation expense.

Other income (expense), net was $1.2 million for the three months ended March 31, 2026 and $1.1 million for the three months ended MarchJune 31,30, 2026 and $0.8 million for the three months ended June 30, 2025. Interest income is earned throughon ourthe Company's cash depositsequivalents and U.S.marketable Treasury-backed money market funds.securities.

Income tax expense was $15,000$16,000 for the three months ended MarchJune 31,30, 2026 for state taxes on interest income generated from the Company's cash equivalents and marketable securities. Income tax expense was nil for the three months ended MarchJune 31,30, 2025.

On August 8, 2023, we filed a prospectus supplement and entered into the Sales Agreement with Stifel, as sales agent, which provides for the issuance and sale by us of up to $100.0 million of shares of common stock from time to time under the ATM program. On February 5, 2024, we issued and sold 1,000,000 shares of common stock at a purchase price of $10.00 per share under the ATM program, resulting in net proceeds of $9.9 million. During the threesix months ended MarchJune 31,30, 2026, the Company sold 237,500 shares of common stock under the Sales Agreement resulting in net proceeds of $1.5 million.

As of MarchJune 31,30, 2026, we had cash, cash equivalents, and marketable securities of $132.3$117.2 million. We believe that our existing cash, cash equivalents, and marketable securities will be sufficient to fund our currently planned operations into the secondfourth halfquarter of 2027. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. We have based this estimate on assumptions that may prove to be wrong, and we could deplete our capital resources sooner than we expect. Additionally, the process of conducting preclinical studies and testing product candidates in clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain.

The following table sets forth a summary of the net cash flow activity for the threesix months ended MarchJune 31,30, 2026 and MarchJune 31,30, 2025 (in thousands):

For the threesix months ended MarchJune 31,30, 2026, net cash used in operating activities was $18.4$34.2 million resulting from our net loss of $17.8$35.6 million and changes in our operating assets and liabilities of $4.0$5.6 million, partially offset by non-cash adjustments of $3.3$6.9 million. The net changes in our operating assets and liabilities were primarily due to a decrease of $3.5$4.0 million in accrued expenses. The change was further driven by a decrease in operating lease liabilities of $1.6 million. The non-cash adjustments included $2.9$6.2 million of stock-based compensation, $0.3$0.6 million of depreciation expense, $0.9$1.9 million of amortization and interest accretion on our operating lease, and $0.8$1.7 million of amortization of discounts on our marketable securities.

For the threesix months ended MarchJune 31,30, 2025, net cash used in operating activities was $22.9$46.5 million resulting from our net loss of $30.2$53.3 million,million partially offset byand changes in our operating assets and liabilities of $3.2$1.2 millionmillion, andpartially offset by non-cash adjustments of $4.1$7.9 million. The net changes in our operating assets and liabilities were primarily due to ana increasedecrease in accruedoperating expenseslease liabilities of $2.7 million, as a result of the timing of manufacturing campaigns, and an increase in accounts payable of $0.9$1.5 million. The change was further driven by a decrease in operatingaccounts lease liabilitiespayable of $0.8$0.9 million, an increase in accrued expenses of $0.5 million and a decrease in prepaids and other current assets of $0.3$0.7 million. The non-cash adjustments included $3.4$5.8 million of stock-based compensation, $0.4$0.7 million of depreciation expense, $0.7$1.2 million of amortization of discounts on our marketable securities, and $0.9$1.9 million of amortization and interest accretion on our operating lease. Additionally, there was a non-cash adjustment of $0.7 million related to the impairment of unused lab equipment.

For the threesix months ended MarchJune 31,30, 2026, net cash used in investing activities was $1.5$5.0 million resulting from $28.5$81.9 million in purchases of marketable securities partially offset by $27.0$77.0 million in maturities of marketable securities.

For the threesix months ended MarchJune 31,30, 2025, net cash provided by investing activities was $17.1$32.1 million resulting from $24.0$39.0 million in maturities of marketable securities partially offset by $6.7 million in purchases of marketable securities and $0.1$0.2 million in purchases of property and equipment.

For the threesix months ended MarchJune 31,30, 2026, net cash provided by financing activities was $1.5 million resulting primarily from proceeds from the sale of shares of common stock under the Sales Agreement.

For the threesix months ended MarchJune 31,30, 2025, there was nonet cash used in or provided by financing activities.activities was $0.1 million of proceeds from the purchase of shares under employee equity plans.