The FDA has put a clinical hold on a Tenaya Therapeutics gene therapy study while the biotech works to standardize activities related to the immunosuppression regimen across trial sites.
Tenaya said the FDA asked it to change the protocol for a phase 1b/2a trial of the gene therapy TN-201 in MYBPC3-associated hypertrophic cardiomyopathy. The request followed proactive correspondence with the FDA about the next steps for TN-201, the biotech said, and was mainly based on data the trial’s data safety monitoring board (DSMB) reviewed in the summer.
While the DSMB signed off on enrollment in expansion cohorts at two doses in July, the FDA has identified a need to standardize immunosuppression patient monitoring and management activities across the trial sites. Tenaya attributed the clinical hold to the FDA’s request for a protocol amendment.
The biotech said TN-201 has been generally well tolerated so far, adding that no new meaningful safety events associated with the gene therapy have emerged since the DSMB review. Tenaya plans to resume dosing once the protocol changes have been implemented at trial sites and doesn’t expect the FDA hold to affect data milestones or development timelines for TN-201.
The biotech shared data from the phase 1b/2a trial over the weekend at the American Heart Association’s 2025 Scientific Sessions. The company said shortening the course of immunosuppression resulted in the second cohort having faster tapers and lower cumulative corticosteroid doses, despite patients receiving more of TN-201 than their peers in the first cohort.
Initial results for the participants in the second cohort showed early dose-responsive increases in TN-201 transduction and MyBP-C protein expression. MyBP-C expression increased by 14% after 12 weeks in the first evaluable patient in the second cohort. Tenaya reported an average 4% increase from the first biopsy to Week 52 in the first cohort.
Cardiac troponin I levels declined 48% to 74% to normal or near-normal levels in all patients in the first cohort. TD Cowen analysts highlighted troponin data when they saw initial data from the trial 11 months ago, telling investors the normalization of levels of the biomarker in one patient was a particularly encouraging sign.