10-K: Passage Bio's 2025 10-K: Gene Therapy Progress Amidst Losses

Passage Bio reports continued operating losses in its 2025 annual filing, advancing its lead gene therapy candidate PBFT02 for neurodegenerative diseases while navigating financial and operational challenges.

Summary

• Passage Bio is a clinical-stage genetic medicines company focused on developing one-time gene therapies for neurodegenerative diseases.
• The lead clinical product candidate, PBFT02, is a gene replacement therapy utilizing an AAV1 capsid for intra cisterna magna (ICM) administration, targeting FTD-GRN, FTD-C9orf72, ALS, and AD.
• The upliFT-D trial for FTD-GRN showed robust and durable increases in CSF PGRN levels (mean 12.4 ng/mL at 1 month, 25.9 ng/mL at 12 months, 23.8 ng/mL at 18 months for Dose 1), exceeding healthy adult controls (3.3-8.2 ng/mL).
• Dose 1 of PBFT02 resulted in an average 4% increase in plasma neurofilament light chain (NfL) levels at 12 months, compared to an expected 28-29% annual increase in untreated FTD-GRN patients.
• Safety data from the upliFT-D trial (n=8) included 26 treatment-emergent adverse events (TEAEs) related to PBFT02 in seven patients, with three serious TEAEs (venous sinus thrombosis in two patients, hepatotoxicity in one patient) at Dose 1, all asymptomatic and responsive to treatment.
• The upliFT-D trial protocol was amended for Cohort 3 to introduce low-dose prophylactic anticoagulation and exclude patients with a global Clinical Dementia Rating (CDR) score of 2 (moderate), focusing on scores of 0.5 (prodromal) or 1 (mild).
• Clinical development of PBFT02 in FTD-C9orf72 patients has been initiated in Cohorts 4 and 5 of the upliFT-D trial, following positive regulatory feedback.
• A preclinical research program for Huntington's disease (HD) is active through the Gemma Collaboration Agreement, with a clinical candidate expected in the second half of 2026.
• Passage Bio outlicensed three pediatric programs (GM1, Krabbe, MLD) to Gemma, receiving $7.5 million in initial payments to date, with an additional $2.5 million due in May 2025 and $5.0 million due in March 2026, plus potential future milestones and royalties.
• The company restructured its research collaboration and licensing agreement with the University of Pennsylvania (Penn), terminating discovery funding and options, while retaining licenses for FTD, GM1, Krabbe, and MLD.
• A workforce reduction of approximately 55% was implemented in January 2025, leading to the cessation of lab operations in Hopewell, New Jersey, and related impairment charges.
• Net loss for the year ended December 31, 2025, was $45.5 million, an improvement from $64.8 million in 2024.
• The accumulated deficit as of December 31, 2025, was $704.8 million.
• Cash and cash equivalents totaled $46.3 million as of December 31, 2025, up from $37.6 million in 2024.
• A 1-for-20 reverse stock split was effected on July 14, 2025, to regain compliance with Nasdaq's listing requirements.
• An ongoing legal proceeding with a former employee regarding stock settlement is pending review by the Pennsylvania Supreme Court after appellate court affirmed judgment in the company's favor.

Sentiment

Score: 5

Explanation: StockSavvy.ai views this filing as neutral to slightly negative. While the company demonstrated promising early clinical biomarker data for PBFT02 and improved its net loss, it continues to face significant financial challenges, including substantial operating losses and a limited cash runway, necessitating future capital raises. The workforce reduction and ongoing legal proceedings also contribute to a cautious outlook.

Positives

• PBFT02's upliFT-D trial for FTD-GRN demonstrated robust and durable increases in CSF PGRN levels, significantly higher than healthy adult controls.
• Early clinical data for PBFT02 showed an average 4% increase in plasma NfL levels at 12 months, a substantial improvement compared to the expected 28-29% annual increase in untreated FTD-GRN patients, suggesting a potential disease-modifying effect.
• Received positive regulatory feedback on the clinical pathway for PBFT02 in both FTD-C9orf72 and ALS, expanding potential indications.
• Initiated clinical development of PBFT02 in FTD-C9orf72 patients, broadening the program's reach.
• PBFT02 has been granted Orphan Drug Designation by the FDA and European Commission for FTD, and Fast Track Designation by the FDA for FTD-GRN, which could expedite development and provide market exclusivity.
• Successfully completed a Type D Chemistry, Manufacturing, and Controls (CMC) meeting with the FDA, aligning on the analytical plan for a more efficient, high-productivity manufacturing process.
• Developed and received initial positive FDA feedback on a potency assay for PBFT02, positioning the program for late-stage development.
• Outlicensed three pediatric programs (GM1, Krabbe, MLD) to Gemma, securing initial payments of $7.5 million to date and potential for significant future development, commercial milestones ($114 million), and single-digit royalties.
• Net loss decreased to $45.5 million in 2025 from $64.8 million in 2024, indicating improved financial performance.
• Cash and cash equivalents increased to $46.3 million as of December 31, 2025, from $37.6 million in 2024, extending the cash runway through Q1 2027.

Negatives

• The company has a history of operating losses and an accumulated deficit of $704.8 million as of December 31, 2025, and anticipates continued losses for the foreseeable future.
• PBFT02 is currently the sole clinical-stage product candidate, making the company highly dependent on its successful development and commercialization.
• Two patients in the upliFT-D trial experienced serious treatment-emergent adverse events (venous sinus thrombosis, hepatotoxicity) at Dose 1, necessitating protocol amendments.
• A workforce reduction of approximately 55% was implemented in January 2025, leading to the cessation of lab operations in Hopewell, New Jersey, and resulting in $6.1 million in impairment expenses for long-lived assets in 2025.
• A payment of $0.9 million is required to Catalent due to the divestiture of the GM1 program, accrued as of December 31, 2025.
• An ongoing legal proceeding with a former employee regarding stock settlement is still pending review by the Pennsylvania Supreme Court, posing continued legal and financial risk.
• The company effected a 1-for-20 reverse stock split on July 14, 2025, to regain compliance with Nasdaq's listing requirements, indicating prior stock price underperformance.
• The ability to raise additional capital under the ATM Facility is limited by SEC rules (the 'baby shelf rule') due to the public float being less than $75.0 million.

Risks

• The company is a clinical-stage genetic medicines company with a history of operating losses and may not achieve or sustain profitability, anticipating continued losses for the foreseeable future.
• Substantial additional funding will be required to complete preclinical and clinical development and potentially commercialize product candidates, and this financing may not be available on acceptable terms or at all.
• PBFT02 is the sole clinical-stage product candidate, and failure to successfully develop and commercialize it would have material adverse effects on the business.
• Preclinical and clinical development are lengthy, expensive, and have uncertain outcomes, potentially leading to additional expenses or delays in completing development and commercialization.
• The low incidence and prevalence of target disorders (e.g., FTD-GRN prevalence ~18,000 in US/EU) may make patient identification and trial enrollment difficult, leading to delays or slower commercial revenue if approved.
• Gene therapy is a novel technology with unclear and frequently changing regulatory requirements, making it difficult to predict the time and cost of product candidate development and regulatory approval.
• Product candidates may cause undesirable and unforeseen side effects (e.g., venous sinus thrombosis, hepatotoxicity, potential T-cell immune response, liver damage, dorsal root ganglia toxicity), which could delay or prevent regulatory approval, limit commercial potential, or result in significant negative consequences.
• Gene therapies are novel, complex, and difficult to manufacture; manufacturing problems could result in delays in development or commercialization programs.
• Significant competition exists in an environment of rapid technological change, and competitors may achieve regulatory approval before Passage Bio or develop more advanced or effective therapies.
• Reliance on third-party manufacturers to produce clinical supply of product candidates, with no binding agreements for commercialization, poses risks of limited capacity and competition.
• Even if regulatory approval is obtained, products may become subject to unfavorable pricing regulations or third-party coverage and reimbursement policies, harming the business.
• Inability to obtain and maintain patent protection or other necessary intellectual property rights, or if the scope of protection is insufficient, could allow competitors to develop and commercialize similar products.
• Reliance on the collaboration with Gemma for preclinical research and development programs; failure or delay by Gemma, or a breakdown in the collaboration, could materially harm the business.
• Reliance on third parties (CROs, clinical investigators) to conduct clinical trials; non-performance, missed deadlines, or non-compliance could substantially harm the business.
• The outlicensed pediatric products to Gemma may not lead to commercial products, and Passage Bio may not receive milestone payments or future royalties.
• Changes in methods of product candidate manufacturing or formulation may result in additional costs or delays.
• Dependence on third-party suppliers for raw materials and components; loss of suppliers or inability to obtain adequate materials could harm the business.
• Adverse public perception of genetic medicines may negatively impact regulatory approval and/or demand for potential products.
• The company has limited experience designing and implementing pivotal clinical trials, and incorrect assumptions about trial design could adversely affect initiation, enrollment, completion, or regulatory approval.
• Preliminary, topline, or interim data from clinical trials may change as more patient data become available and are subject to audit and verification procedures.
• Regulatory authorities may approve a product candidate for more limited indications than requested or impose significant limitations (e.g., Risk Evaluation and Mitigation Strategies, REMS).
• Disruptions at the FDA or other comparable foreign regulatory authorities may slow the time necessary for new products to be reviewed and/or approved.
• Failure to obtain marketing approval in foreign jurisdictions would prevent product candidates from being marketed abroad and limit full market potential.
• Inability to establish U.S. or global sales and marketing capabilities or enter into agreements with third parties to sell and market product candidates.
• Expending limited resources to pursue a particular product candidate or indication may lead to failure to capitalize on more profitable opportunities.
• All current product candidates and research programs are licensed from or based upon licenses from third parties; termination or narrowing of license agreements could materially adversely affect the ability to advance candidates.
• Third parties may initiate legal proceedings alleging claims of intellectual property infringement, which could be expensive, time-consuming, and unsuccessful.
• Inability to protect the confidentiality of trade secrets could harm the business and competitive position.
• Obtaining and maintaining patent protection depends on compliance with various procedural, document submission, fee payment, and other requirements, and non-compliance could reduce or eliminate patent protection.
• Patent terms may be inadequate to protect the competitive position on product candidates for an adequate amount of time.
• Some in-licensed intellectual property rights were generated through U.S. government funding and are subject to federal regulations such as march-in rights and manufacturing preference requirements.
• The pricing, insurance coverage, and reimbursement status of newly approved products is uncertain, and failure to obtain or maintain adequate coverage and reimbursement could limit marketability.
• Fast Track Designation may not lead to a faster development or regulatory review or approval process.
• Orphan Drug Designation may be unsuccessful or the benefits associated with it may not be maintained.
• Pursuing accelerated approval may not lead to a faster development or regulatory review or approval process and does not increase the likelihood of marketing approval.
• Any approved product candidate will be subject to extensive post-marketing regulatory requirements and could be subject to post-marketing restrictions or withdrawal from the market.
• Product candidates for which approval is sought may face competition from biosimilars approved through an abbreviated regulatory pathway.
• Enacted and future legislation (e.g., Inflation Reduction Act) may affect pricing and third-party payment for product candidates, increasing difficulty and cost to obtain marketing approval.
• Operations and relationships with customers and third-party payors will be subject to applicable anti-kickback, fraud and abuse, and other healthcare laws and regulations, potentially exposing the company to penalties.
• Future success depends on the ability to retain key executives and to attract, retain, and motivate qualified personnel, especially given the recent workforce reductions.
• May be required to expand manufacturing, development, and regulatory capabilities, leading to difficulties in managing growth.
• Internal computer systems, or those of third-party collaborators or contractors, may fail or suffer security breaches and cyber-attacks, disrupting development programs.
• Ability to utilize net operating loss carryforwards may be subject to limitation due to ownership changes.
• U.S. federal income tax reform and changes in other tax laws could adversely affect the company.
• Employees, principal investigators, CROs, and consultants may engage in misconduct or other improper activities.
• Product liability lawsuits could cause substantial liabilities and limit commercialization.
• Subject to U.S. and certain foreign export and import controls, sanctions, embargoes, anti-corruption laws, and anti-money laundering laws and regulations.
• The price of common stock may be volatile and fluctuate substantially, resulting in substantial losses for holders.
• Failure to establish and maintain proper and effective internal control over financial reporting in the future could impair the ability to produce accurate and timely financial statements.
• Will continue to incur increased costs as a public company, and management will devote substantial time to new compliance initiatives.
• As a smaller reporting company, reduced disclosure requirements may make common stock less attractive to investors.
• Exclusive forum provisions in corporate charter documents and Delaware law may limit stockholders' ability to bring claims or discourage lawsuits.
• General economic uncertainty and capital markets disruptions, including fluctuating interest rates, inflation, geopolitical instability, and banking system turmoil, could adversely affect the business.
• Natural disasters could severely disrupt operations, and business continuity and disaster recovery plans may be inadequate.

Future Outlook

Passage Bio expects to continue incurring significant expenses and operating losses for the foreseeable future, requiring substantial additional funding to complete preclinical and clinical development and potential commercialization. Existing cash and cash equivalents are projected to fund operations through the end of the first quarter of 2027. The company plans to report updated interim safety and biomarker data from the PBFT02 Dose 2 FTD trial and seek regulatory feedback on registrational trial design in FTD-GRN in the first half of 2026. A clinical candidate for the Huntington's disease program is expected in the second half of 2026. The company anticipates significant impacts from the Inflation Reduction Act on pharmaceutical pricing and faces uncertainty regarding future regulatory policies.

Management Comments

• We believe we have developed a differentiated approach to developing treatments for central nervous system, or CNS, disorders that allows us to select and advance product candidates with a higher probability of technical and regulatory success.
• We believe this clinical product candidate [PBFT02] has the potential to provide patients with significantly improved outcomes given the rigorous capsid and transgene selection process, and our chosen route of ICM administration, which provides the potential for enhanced benefits due to widespread vector delivery to the brain and spinal cord and an improved safety profile compared with systemic administration, due to the lower doses required.
• We have no current plan to issue any shares of preferred stock.
• We believe that the benefits of increased protection of our potential ability to negotiate with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire us because negotiation of these proposals could result in an improvement of their terms.
• We believe the quality, reliability and scalability of our genetic medicine manufacturing techniques and expertise will be a critical advantage to our long-term success.
• We believe Catalent is capable of producing enough supply to support our planned clinical trials of our current clinical product candidate, and its initial commercial launch if approved.
• We intend to continue to defend against this claim [former employee lawsuit].
• Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives, and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

Industry Context

StockSavvy.ai notes that the genetic medicines field is characterized by rapidly changing technologies and intense competition. Passage Bio operates in a highly competitive biotechnology and pharmaceutical industry, facing numerous larger companies and academic institutions with greater financial and technical resources. The focus on rare neurodegenerative diseases like FTD-GRN (prevalence ~18,000 in US/EU) positions Passage Bio in a niche market, where high reimbursement rates are crucial for commercial viability. The company's strategy of advancing a single genetic medicine candidate (PBFT02) for multiple indications (FTD-GRN, FTD-C9orf72, ALS, AD) is a cost-effective approach in this capital-intensive industry, aiming to leverage shared R&D costs and streamlined regulatory processes. The ongoing legal challenges to the Inflation Reduction Act's drug pricing negotiation provisions highlight the significant regulatory uncertainty impacting the pharmaceutical industry's future revenue models.

Comparison to Industry Standards

• PBFT02's observed 4% increase in plasma NfL levels at 12 months post-treatment contrasts favorably with an expected 28-29% annual increase in untreated symptomatic FTD-GRN patients, based on ALLFTD natural history data and published data (Saracino 2021). This suggests a potential disease-modifying effect compared to the natural progression of the disease.
• CSF PGRN levels for Dose 1 of PBFT02 (mean 12.4 ng/mL at 1 month, 25.9 ng/mL at 12 months, 23.8 ng/mL at 18 months) are significantly higher than the range found in healthy adult controls (3.3 to 8.2 ng/mL, mean 4.8 ng/mL). This indicates successful elevation of the target protein.
• Preclinical studies showed ICM AAV1 administration in NHPs resulted in superior CSF human PGRN levels (greater than five-fold higher) compared to AAVhu68 or AAV5 serotypes, suggesting a potentially optimized delivery method.
• Competitors in FTD-GRN include AviadoBio Ltd (Phase 1/2 gene therapy trial), Denali Therapeutics Inc. (Phase 1/2 recombinant progranulin protein), Vesper Bio ApS (Phase 1/2 small molecule sortilin antagonist), and Arkuda Therapeutics (preclinical small molecule progranulin enhancer).
• Competitors in Huntington's disease targeting MSH3 include Evox Therapeutics Ltd, Latus Bio, Inc., uniQure N.V., and Voyager Therapeutics, Inc.

Corporate Governance

Legal Proceedings

• The company is the defendant in litigation with a former employee who filed a lawsuit in the Court of Common Pleas of Philadelphia County, asserting claims for breach of contract and violation of the Pennsylvania Wage Payment and Collection Law.
• The plaintiff contended a binding settlement agreement from February 2020 promised 150,000 shares of stock and additional compensation, not subject to a reverse stock split.
• The company responded that any shares offered in settlement negotiations in 2020 would be subject to the reverse split, entitling the plaintiff to 33,836 shares (1,692 shares adjusted for the 2025 reverse stock split).
• A trial in October 2024 resulted in a jury finding an agreement was reached but agreeing with the company that shares were subject to the reverse split, awarding damages roughly equal to the company's offer.
• On December 12, 2024, the presiding judge delivered a judgment in the company's favor, finding no binding agreement and that the plaintiff was not entitled to damages.
• The plaintiff appealed to the Superior Court of Pennsylvania on December 23, 2024.
• On September 25, 2025, the appellate court affirmed the entry of judgment in favor of the company.
• On October 7, 2025, the plaintiff filed an Application for Reargument to the Superior Court of Pennsylvania, which was denied in December 2025.
• In December 2025, the plaintiff petitioned for review of their appeal to the Pennsylvania Supreme Court, which is currently pending.
• The company intends to continue to defend against this claim.

Related Party Transactions

• The company has a research, collaboration, and license agreement with Gemma Biotherapeutics, Inc. (Gemma), which is comprised of a core research team from the University of Pennsylvania's Gene Therapy Program (GTP). This relationship, while not explicitly labeled as a 'related party transaction' in the dedicated section, involves significant collaboration and financial arrangements, including milestone payments and royalties, suggesting a close operational and financial tie.

Stakeholder Impact

• **Shareholders**: Face potential dilution from future equity offerings, stock price volatility, and no anticipated cash dividends. Anti-takeover provisions may limit acquisition premiums. The 1-for-20 reverse stock split aimed to maintain Nasdaq listing but impacts share count and per-share metrics.
• **Employees**: Experienced a significant workforce reduction (55%) in January 2025, leading to job losses and potential impact on morale and institutional knowledge. The company offers a competitive compensation and benefits package, including equity ownership, to attract and retain talent in a highly competitive industry.
• **Patients**: Are the primary focus of the company's mission to develop one-time gene therapies for life-threatening neurodegenerative diseases with limited treatment options. Clinical trial progress, while promising, carries inherent risks of adverse events and uncertain outcomes.
• **Creditors**: The company's accumulated deficit and anticipated future losses indicate a reliance on external funding, which could pose risks to creditors if financing is not secured.
• **Partners (Gemma, Penn, Catalent)**: The company's business model relies heavily on collaborations for research, development, manufacturing, and intellectual property. Changes in these relationships, such as the restructuring of the Penn agreement and the outlicensing to Gemma, directly impact operational strategy and financial obligations (e.g., payments to Catalent for divestiture).

Next Steps

• Report updated interim safety and biomarker data from Dose 2 in FTD patients in the first half of 2026.
• Seek regulatory feedback on registrational trial design in FTD-GRN in the first half of 2026.
• Declare a clinical candidate for the Huntington's disease program in the second half of 2026.
• Actively pursue opportunities to sublease all remaining laboratory space in Hopewell, New Jersey.
• Continue to defend against the former employee's lawsuit, which is pending review by the Pennsylvania Supreme Court.
• Continue to monitor and enhance cybersecurity capabilities.

Key Dates

Recommendation

Passage Bio's 2025 10-K presents a mixed picture. The positive biomarker data for PBFT02 in FTD-GRN and the reduction in net loss are encouraging, suggesting progress in its core therapeutic area and financial management. However, the company remains a clinical-stage entity with a substantial accumulated deficit and a limited cash runway, necessitating further capital raises. The serious adverse events in the PBFT02 trial, while managed, underscore the inherent risks in gene therapy development. The workforce reduction and ongoing legal dispute add layers of operational and reputational uncertainty. Given the promising early clinical signals balanced against significant financial and development risks, a 'Hold' recommendation is appropriate for investors awaiting further de-risking of the pipeline and a clearer path to profitability.

Keywords

Gene therapy, Neurodegenerative diseases, FTD-GRN, PBFT02, Frontotemporal dementia, Huntington's disease, AAV1, Clinical trials, Orphan Drug, Fast Track, Biotechnology, Pharmaceutical, Genetic medicines, TDP-43, Progranulin, Lysosomal function, Nasdaq, Financial results, R&D, Clinical stage, Biologics, Manufacturing, Intellectual property, Corporate governance, Risk management, SEC filing, 10-K