The FDA placed a clinical hold on Tenaya Therapeutics’ gene therapy study for heart disease while the company standardizes immunosuppression regimens across trial sites. Regulators requested harmonized protocols to mitigate immune‑related risks and ensure consistent safety monitoring, pausing patient enrollment and dosing until Tenaya addresses the agency’s conditions. Tenaya will need to submit revised protocols and potentially additional safety data before the hold is lifted; the pause affects timelines for the program’s IND‑enabling path and could delay any pivotal plans. The agency’s action highlights ongoing regulatory scrutiny for in vivo gene therapies, especially concerning immunomodulation strategies. Investors and partners will watch the company’s response and the speed of regulatory re‑engagement to gauge whether the program’s clinical and commercial prospects remain intact.