The FDA has placed a clinical hold on Tenaya Therapeutics’ cardiac gene therapy trial while the company standardizes immunosuppression practices across participating sites, the agency and company filings show. The hold suspends dosing until Tenaya provides updated protocols and harmonized site procedures for managing immune responses tied to vector‑based gene delivery. Tenaya said it is working with investigators to align immunosuppression regimens and expects to supply the FDA with corrective actions. The pause underscores persistent regulatory scrutiny over safety management in in‑vivo gene therapy trials and the operational challenges of multi‑site immunomodulation.