Tenaya Therapeutics Inc. (NASDAQ: TNYA) reported interim data from its MyPEAK-1 Phase 1b/2 clinical trial showing that gene therapy treatment TN-201 improved cardiac function and reduced symptoms in patients with MYBPC3-associated hypertrophic cardiomyopathy.

The trial evaluated seven patients across two dose levels of TN-201. Six evaluable patients demonstrated reductions in left ventricular mass index, a measure of heart muscle thickening that defines the condition. All patients showed improvements in multiple disease parameters including cardiac troponin levels and symptom burden assessments.

Five of six patients improved by at least one class on the New York Heart Association classification scale, with all five now classified as Class I with no heart failure symptoms interfering with daily activities. Four patients showed meaningful improvements in quality of life scores, with the higher-dose group achieving a mean 36-point increase on the Kansas City Cardiomyopathy Questionnaire.

Three patients demonstrated improved exercise capacity, with walking test improvements ranging from 50 to 255 meters. Cardiac biopsy results showed TN-201 successfully delivered genetic material and increased MyBP-C protein levels by an average of 4%.

The treatment was generally well tolerated at both dose levels, with no dose-limiting toxicities observed. Benefits in the lower-dose group remained sustained at two years of follow-up, while the higher-dose group showed improvements at earlier timepoints.

TN-201 received PRIME designation from the European Medicines Agency and was accepted into the FDA's Rare Disease Evidence Principles process for pediatric patients. The company plans to provide additional long-term follow-up data in the second half of 2026 and is engaging with regulators on pivotal study design.