On December 11, 2025, Tenaya Therapeutics, Inc. (TNYA) filed an 8-K form with the U.S. Securities and Exchange Commission disclosing positive interim data from its RIDGE-1 clinical trial. The filing revealed that TN-401, the company's investigational gene therapy for PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC), demonstrated promising results in the first cohort of patients.

According to the filing, TN-401 was well tolerated and increased PKP2 protein expression in two of three patients evaluated as of the October 2025 data cut-off. The therapy also showed meaningful reductions in premature ventricular contractions (PVCs) and non-sustained ventricular tachycardias (NSVTs), which are established risk factors for dangerous sustained arrhythmias. The company noted these findings represent initial data less than one year after patient dosing began.

"We are excited by the strength of the data for TN-401 at this relatively early timepoint in the RIDGE-1 trial. Less than a year after dosing, initial data indicate a promising safety profile, consistent transduction of the gene therapy in cardiomyocytes and RNA and protein expression, and meaningful reductions in PVCs and NSVTs, well-established risk factors for dangerous sustained arrhythmias." — Whit Tingley, Chief Medical Officer, Tenaya Therapeutics

The filing also confirmed that TN-401 has received both Orphan Drug and Fast Track Designations from the U.S. Food and Drug Administration for the treatment of PKP2-associated ARVC. Tenaya Therapeutics held a conference call on December 11, 2025, to review these preliminary results and provide updates on the ongoing RIDGE-1 Phase 1b/2 trial.

Chief Medical Officer Whit Tingley commented that these findings represent an important milestone in TN-401's development. The company expressed gratitude to patients and investigators involved in both the RIDGE-1 clinical trial and the RIDGE natural history study of PKP2-associated ARVC, according to the SEC filing.