By Peter.
Biotech firm Tenaya Therapeutics (NASDAQ: TNYA) disclosed on Friday that the U.S. Food and Drug Administration (FDA) has imposed a clinical hold on its MyPEAK-1 Phase 1b/2a trial evaluating the experimental gene therapy TN-201. The therapy targets MYBPC3-associated hypertrophic cardiomyopathy (HCM), a rare inherited condition causing abnormal heart muscle thickening and impaired blood pumping, affecting about 1 in 500 people worldwide.
The hold halts new patient enrollments and dosing, a standard FDA mechanism to address potential safety or protocol concerns during early-to-mid-stage studies.
Key Details of the Hold
- Reason: The FDA requested protocol revisions to standardize patient monitoring and immunosuppression management (drugs preventing immune rejection of the therapy). This stems from prior data reviewed by the trial’s independent Data Safety Monitoring Board (DSMB) in summer 2025.
- Safety Profile: The DSMB deemed TN-201’s risks acceptable, greenlighting expansion to two dose levels (3E13 vg/kg and 6E13 vg/kg). Tenaya reports no new significant safety signals since then, with the therapy generally well-tolerated to date.
- Next Steps: Tenaya is collaborating with the FDA to implement changes at trial sites. Dosing is expected to resume soon, with no anticipated delays to data readouts or the overall timeline.
About TN-201 and the MyPEAK-1 Trial
TN-201 is an adeno-associated virus (AAV9)-based gene therapy designed to deliver a functional MYBPC3 gene copy, addressing the root cause of this monogenic HCM form (impacting ~15% of cases). The trial, launched in 2023, enrolls adults with confirmed MYBPC3 mutations and symptomatic HCM.
| Trial Phase | Patients Enrolled | Primary Endpoint | Status Pre-Hold |
|---|---|---|---|
| Phase 1b/2a | ~10–20 (early cohorts) | Safety & tolerability | DSMB-approved expansion |
Interim safety/efficacy data from Cohorts 1–2 are slated for presentation at the American Heart Association (AHA) Scientific Sessions 2025 (November 8–10, New Orleans), with a webcast review on November 10.
Market Impact
TNYA shares tumbled over 20% in after-hours trading on Friday, reflecting investor jitters over clinical holds in gene therapy—despite the company’s reassuring outlook. Year-to-date, the stock is down ~15%, trading around $2–3 per share amid biotech sector volatility.
Broader Context for Tenaya
South San Francisco-based Tenaya focuses on curative heart disease therapies via gene editing, cellular reprogramming, and gene addition. Pipeline highlights:
- TN-201 (MyBPC3 HCM): Lead program; potential BLA filing by 2027 if successful.
- TN-401 (PKP2-ARVC): Phase 1b/2a for arrhythmogenic right ventricular cardiomyopathy.
- TN-301 (HFpEF): Phase 1b small-molecule for heart failure with preserved ejection fraction.
This hold, while a setback, aligns with FDA scrutiny on gene therapies’ immune risks (e.g., AAV immunogenicity). Tenaya’s proactive response and intact timelines could mitigate long-term damage, especially with AHA data looming. Investors should monitor the November 10 call for updates. #TNYA #GeneTherapy #HCM
