June 03, 2026 —
Tenaya Therapeutics reported new interim safety and efficacy data from the MyPEAK-1 Phase 1b/2 trial of TN-201, an investigational AAV-based gene therapy being developed for MYBPC3-associated hypertrophic cardiomyopathy, or HCM.
MYBPC3-associated HCM is caused by insufficient levels of myosin-binding protein C, a key cardiac protein involved in normal heart muscle function. Patients in the MyPEAK-1 trial had severe nonobstructive HCM, with pronounced cardiac hypertrophy and heart failure symptoms despite standard-of-care treatment.
The updated data include 78–104 weeks of follow-up for three patients treated at 3E13 vg/kg in Cohort 1 and 26–52 weeks of follow-up for four patients treated at 6E13 vg/kg in Cohort 2. Among six patients evaluable for efficacy, TN-201 was associated with improvements across multiple clinical measures, including cardiac hypertrophy, symptom burden, and functional capacity.
All six evaluable patients achieved reductions in left ventricular mass index, a key measure of cardiac hypertrophy. Five of six patients also showed reductions in one or more measures of wall thickness. In Cohort 1, reductions in LVMI were sustained as far out as two years for the first two treated patients. In Cohort 2, patients treated at the higher dose showed evidence of improvement at earlier timepoints, suggesting a potential dose response.
Symptom improvement was also observed. Five of six evaluable patients improved by at least one New York Heart Association functional class, and all five are now Class I, meaning heart failure symptoms no longer interfere with activities of daily living. Four of six patients also demonstrated meaningful improvement in Kansas City Cardiomyopathy Questionnaire Clinical Summary Scores, with increases ranging from 12 to 56 points. Among the three evaluable Cohort 2 patients, the mean KCCQ-CSS increase was 36 points.
Functional capacity improved in three patients based on either six-minute walk test or cardiopulmonary exercise testing. Three patients achieved clinically meaningful improvements in six-minute walk distance, ranging from 50 to 255 meters, with two of these patients from Cohort 2. One Cohort 2 patient also demonstrated clinically meaningful improvement in peak oxygen consumption.
Biopsy data provided evidence of TN-201 activity in cardiac tissue. Serial cardiac biopsies showed robust TN-201 DNA transduction and mRNA expression, with MyBP-C protein levels increasing by an average of 4% over time. MyBP-C levels increased in four of six patients as of the most recent assessment.
TN-201 was generally well tolerated at both dose levels, with no dose-limiting toxicities and no new TN-201-associated safety events reported since the prior data readout. All patients have tapered off immunosuppressive medicines.
Tenaya continues to enroll adults at the 6E13 vg/kg dose to further characterize safety and efficacy and support dose selection. The company plans to share additional long-term follow-up data in the second half of 2026 and is engaging regulators on the path toward pivotal studies.
The company also announced that TN-201 has received PRIME designation from the European Medicines Agency and that the pediatric indication for biallelic MYBPC3-associated HCM has been accepted into the FDA’s Rare Disease Evidence Principles process, supporting early regulatory engagement for this ultra-rare population.
