Key points: The U.S. FDA has placed a clinical hold on Tenaya Therapeutics’ TN-201 gene therapy trial for hypertrophic cardiomyopathy linked to MYBPC3 mutations. The agency requested protocol changes to standardize monitoring and strengthen immunosuppression management. Tenaya says the decision relied largely on data reviewed by the trial's independent safety board in summer 2025, that TN-201 has been generally well tolerated, and that the company does not expect delays to planned data releases or its development timeline.
FDA Places Clinical Hold on Tenaya’s TN-201 Gene Therapy Trial for Rare Inherited Heart Disease
Key points: The U.S. FDA has placed a clinical hold on Tenaya Therapeutics’ TN-201 gene therapy trial for hypertrophic cardiomyopathy linked to MYBPC3 mutations. The agency requested protocol changes to standardize monitoring and strengthen immunosuppression management. Tenaya says the decision relied largely on data reviewed by the trial's independent safety board in summer 2025, that TN-201 has been generally well tolerated, and that the company does not expect delays to planned data releases or its development timeline.
02:32, 08.11.2025Health
FDA places clinical hold on Tenaya's TN-201 trial
Tenaya Therapeutics said the U.S. Food and Drug Administration has placed a clinical hold on its clinical trial of TN-201, an experimental gene therapy for hypertrophic cardiomyopathy caused by mutations in the MYBPC3 gene.
The company’s shares fell more than 20% in after-hours trading following the announcement.
The early-to-mid-stage study tests TN-201 in patients whose heart muscle thickens abnormally, reducing pumping efficiency. The FDA has asked Tenaya to amend the trial protocol to standardize patient monitoring and tighten procedures for managing immunosuppression medications used to limit immune reactions to the gene therapy.
Tenaya said the agency’s action was based largely on material already reviewed by the trial’s independent safety review board in summer 2025, which had determined TN-201’s safety profile to be acceptable and allowed expanded enrollment at two dose levels.
According to the company, TN-201 has been generally well tolerated with no major new safety signals since that review. Tenaya said it is working with the FDA to implement the requested protocol changes and intends to resume patient dosing once the revised procedures are in place at study sites.
Outlook: Tenaya said it does not expect the clinical hold to delay planned data releases or alter the therapy’s overall development timeline.
Reporting by Kamal Choudhury; editing by Shilpi Majumdar.