8-K: Passage Bio Advances FTD Gene Therapy, Reports Q3 Financials

Passage Bio reports progress in its upliFT-D clinical trial for FTD-GRN and FTD-C9orf72, aligns with FDA on manufacturing, and extends cash runway into Q1 2027.

Summary

• Passage Bio is actively enrolling Cohort 3 (FTD-GRN) and Cohort 4 (FTD-C9orf72) patients in its upliFT-D clinical trial for PBFT02, evaluating Dose 2.
• The company aligned with the U.S. Food and Drug Administration (FDA) on an analytical approach to establish comparability for a high-productivity, suspension-based PBFT02 manufacturing process.
• The new manufacturing process is estimated to yield over 1,000 doses of PBFT02 at Dose 2 per batch, with over 90% purity and over 70% full capsids.
• Passage Bio expects to obtain regulatory feedback on its FTD-GRN registrational trial design in the first half of 2026, including discussions on a potential single-arm design.
• Cash, cash equivalents, and marketable securities were $52.8 million as of September 30, 2025, down from $84.8 million as of September 30, 2024.
• The company projects its current cash runway will fund operations into the first quarter of 2027.
• Net loss for Q3 2025 was $7.7 million, or $2.44 per basic and diluted share, a reduction from $19.3 million, or $6.15 per share, in Q3 2024.
• Research and Development (R&D) expenses decreased to $4.3 million in Q3 2025 from $8.7 million in Q3 2024.
• General and Administrative (G&A) expenses decreased to $4.3 million in Q3 2025 from $7.3 million in Q3 2024.
• Interim safety data for PBFT02 (as of June 15, 2025) showed 5 of 8 patients experienced mild to moderate treatment-emergent adverse events, with 3 patients experiencing 4 serious adverse events (asymptomatic venous sinus thrombosis, hepatotoxicity, pulmonary embolism).
• A revised immunosuppression regimen was implemented following initial safety observations, and no DRG toxicity or ICM administration complications were reported.
• PBFT02 demonstrated robust, durable increases in CSF Progranulin (PGRN) in FTD-GRN patients, with one Dose 2 patient reaching 7.6 ng/mL at Month 1, approaching the upper healthy adult range.
• Plasma NfL (neurofilament light chain) showed early evidence of improvement, with PBFT02-treated patients (n=4) having a reduced annual rate of change compared to published natural history data (3.7% vs. 29.0% and 28.0%).

Sentiment

Score: 8

Explanation: The filing presents a strong positive outlook, driven by significant clinical trial progress, successful regulatory alignment on manufacturing, and improved financial efficiency leading to a reduced net loss and extended cash runway. The biomarker data for PBFT02 is promising, and the company's strategic regulatory discussions for a registrational trial are key de-risking factors. While a net loss persists and some SAEs occurred, the overall trajectory and operational advancements are highly favorable.

Positives

• Active enrollment in Cohort 3 (FTD-GRN) and Cohort 4 (FTD-C9orf72) of the upliFT-D study for PBFT02, indicating clinical trial progression.
• Successful alignment with the FDA on an analytical approach for a high-productivity, suspension-based PBFT02 manufacturing process, de-risking future supply.
• The new manufacturing process significantly improves productivity, purity (>90%), and full capsids (>70%), with an estimated yield of over 1,000 doses per batch.
• On track to obtain regulatory feedback on FTD-GRN registrational trial design in 1H 2026, including the possibility of a single-arm design, which could accelerate approval pathways.
• Cash runway extended into Q1 2027, providing financial stability for ongoing operations and clinical development.
• Significant reduction in net loss for Q3 2025 to $7.7 million from $19.3 million in Q3 2024, reflecting improved financial efficiency.
• Decreased Research and Development (R&D) expenses to $4.3 million in Q3 2025 from $8.7 million in Q3 2024, indicating cost management.
• Decreased General and Administrative (G&A) expenses to $4.3 million in Q3 2025 from $7.3 million in Q3 2024, further demonstrating cost control.
• Interim clinical data shows robust and durable increases in CSF PGRN levels in FTD-GRN patients treated with PBFT02, with one Dose 2 patient reaching 7.6 ng/mL at Month 1, approaching the healthy adult range.
• Early evidence of improvement in plasma NfL, a disease progression biomarker, in PBFT02-treated patients compared to natural history data, suggesting potential disease modification.
• No evidence of DRG toxicity or complications during ICM administration of PBFT02, supporting the safety profile of the delivery method.

Negatives

• Cash, cash equivalents, and marketable securities decreased to $52.8 million as of September 30, 2025, from $84.8 million as of September 30, 2024, indicating continued cash burn.
• Three out of eight patients in the upliFT-D study experienced a total of four serious adverse events (SAEs), including asymptomatic venous sinus thrombosis, hepatotoxicity, and pulmonary embolism, requiring protocol amendments.
• The company continues to operate at a net loss, despite reductions, indicating it is not yet profitable.

Risks

• Ability to develop and obtain regulatory approval for product candidates.
• Timing and results of preclinical studies and clinical trials, which may not be favorable.
• Risks associated with clinical trials, including managing clinical activities, unexpected concerns from additional data, and regulatory authorities requiring more information or further studies, or delaying/failing to approve drug candidates.
• Occurrence of adverse safety events in clinical trials.
• Risk that positive results in preclinical or early-stage clinical trials may not be replicated in subsequent or later-stage trials.
• Failure to protect and enforce intellectual property and other proprietary rights.
• Dependence on collaborators and other third parties for the development and manufacture of product candidates and other business aspects, which are outside of full control.
• Risks associated with current and potential delays, work stoppages, or supply chain disruptions.

Future Outlook

Passage Bio anticipates reporting updated interim safety and biomarker data from Dose 2 of the upliFT-D study in the first half of 2026. The company also plans to seek regulatory feedback from the FDA on the FTD-GRN registrational trial design, including the possibility of a single-arm design with a natural history control, in the first half of 2026. The current cash, cash equivalents, and marketable securities are expected to fund operations into the first quarter of 2027. The company is also exploring the benefits of elevated progranulin in multiple adult neurodegenerative diseases and advancing its Huntington's disease preclinical program.

Management Comments

• "We are pleased to report that we have opened enrollment in our third FTD-GRN and first FTD-C9orf72 patient cohorts in our ongoing upliFT-D clinical trial of PBFT02. We recognize the urgent need for the development of disease-modifying therapies for the FTD patient community, and we remain focused on advancing our study expeditiously."
• "In addition, we completed a successful meeting with the FDA where we aligned on key elements of an analytical comparability plan to support the future use of our high-productivity, suspension-based manufacturing process for PBFT02 in a registrational study."
• "As we look towards the first half of 2026, we are excited to share additional data to further inform our understanding of the potential of PBFT02 and initiate discussions with the FDA on a registrational study design in FTD-GRN."

Industry Context

Passage Bio operates in the highly competitive and rapidly evolving field of genetic medicines for neurodegenerative diseases. The focus on Frontotemporal Dementia (FTD), particularly FTD-GRN and FTD-C9orf72, addresses a significant unmet medical need as there are currently no approved disease-modifying therapies. The company's strategy of developing a one-time gene replacement therapy delivered via intra-cisterna magna (ICM) injection aligns with broader industry trends towards targeted, high-impact therapies for rare genetic disorders. The emphasis on manufacturing scalability and regulatory alignment for a registrational trial reflects the critical path for gene therapies to market, where CMC (Chemistry, Manufacturing, and Controls) is often a bottleneck. The exploration of PBFT02's potential across multiple neurodegenerative diseases, including ALS and Alzheimer's, positions Passage Bio within the broader effort to leverage gene therapy platforms for widespread neurological conditions.

Comparison to Industry Standards

• PBFT02 (AAV1 gene therapy delivering GRN via ICM) achieved mean CSF PGRN levels of 26 ng/mL at 12 months (n=4) with durability at 18 months (n=2).
• A competitor's AAV9 gene therapy delivering GRN via ICM achieved CSF PGRN levels of approximately 4-8 ng/mL (n=7 higher dose) at 12 months, with levels declining from 2 to 12 months.
• PBFT02's CSF PGRN levels are significantly higher and more durable compared to publicly disclosed data from other AAV gene therapies for FTD-GRN, positioning it as a potential best-in-class therapeutic.
• The company's manufacturing process for PBFT02, yielding over 1,000 doses per batch with high purity and full capsids, demonstrates a competitive advantage in scalability and product quality for gene therapy manufacturing.

Stakeholder Impact

• **Shareholders:** Positive impact due to reduced net loss, extended cash runway, and significant clinical and regulatory progress which de-risks the lead program. The potential for a best-in-class therapy and accelerated regulatory pathway could increase long-term value.
• **Patients (FTD-GRN, FTD-C9orf72):** Highly positive impact as the clinical trial progresses, manufacturing is de-risked, and regulatory discussions advance towards a potential registrational study for a disease with no approved modifying therapies. The amended protocol also aims to optimize patient enrollment and safety.
• **Employees:** Positive impact from continued progress and financial stability, suggesting job security and a clear path forward for the company's mission.
• **Regulatory Authorities (FDA):** Continued engagement and alignment on manufacturing and trial design demonstrate a collaborative approach, which is crucial for successful drug development and approval.

Next Steps

• Report updated interim safety and biomarker data from Dose 2 of the upliFT-D study in 1H 2026.
• Seek regulatory feedback from the FDA on the FTD-GRN registrational trial design in 1H 2026.
• Continue active enrollment of Cohort 3 (FTD-GRN) and Cohort 4 (FTD-C9orf72) patients in the upliFT-D study.
• Advance the Huntington's disease preclinical program.
• Further explore the benefits of elevated progranulin in multiple adult neurodegenerative diseases.

Key Dates

Recommendation

The filing indicates strong operational execution and significant de-risking events for Passage Bio's lead gene therapy candidate, PBFT02. The substantial reduction in net loss, coupled with an extended cash runway into Q1 2027, demonstrates improved financial management and provides a longer operational horizon. Clinically, the active enrollment in advanced cohorts, robust and durable biomarker responses (CSF PGRN, plasma NfL), and the absence of DRG toxicity are highly encouraging. Crucially, the alignment with the FDA on manufacturing comparability and the planned discussions for a single-arm registrational trial design for FTD-GRN represent major positive catalysts that could accelerate the path to market. Compared to competitors, PBFT02 shows superior and more durable PGRN elevation. These factors collectively suggest a strong positive trajectory for the company, making it an attractive 'buy' for investors seeking exposure to the gene therapy space for neurodegenerative diseases.

Keywords

Passage Bio, PASG, Gene Therapy, Neurodegenerative Diseases, Frontotemporal Dementia, FTD-GRN, FTD-C9orf72, PBFT02, UpliFT-D, Clinical Trial, FDA, Manufacturing, Progranulin, PGRN, Neurofilament Light Chain, NfL, Biomarker, Cash Runway, Financial Results, Q3 2025, Biotechnology, Rare Disease