Tenaya Therapeutics has commenced its Phase 1b RIDGE-1 clinical trial (NCT06228924) with the first patient dosed with TN-401, an adeno-associated virus (AAV)-based gene therapy targeting PKP2-associated arrhythmogenic right ventricular cardiomyopathy (ARVC). This marks a significant step forward in addressing the underlying genetic cause of this life-threatening heart condition.
The initial dosing occurred at the University of California, San Francisco, with plans to expand the study to multiple centers across the United States, United Kingdom, and Europe. The first patient received a dose of 3x1013 vg/kg of TN-401, a dosage that demonstrated "near-maximal efficacy" in preclinical studies. An independent safety review panel will assess the results after two more patients are treated at this dose level before potential dose escalation or expansion.
Trial Design and Patient Selection
The RIDGE-1 trial aims to enroll approximately 15 patients who have an implantable cardioverter defibrillator and exhibit an elevated risk of arrhythmias based on premature ventricular contraction counts during screening. Tenaya anticipates releasing initial data from the trial in the coming year.
TN-401: A Novel Approach to ARVC Treatment
TN-401 is designed to deliver a fully functional copy of the PKP2 gene directly to heart cells using an AAV9 capsid. This approach is intended to correct the genetic defect responsible for ARVC, unlike current treatments that only manage symptoms. Preclinical studies have shown that TN-401 can normalize heart rhythms, reverse disease progression, and extend survival in animal models.
Expert Commentary
"People living with ARVC frequently experience dangerous arrhythmias and are at risk for developing heart failure, cardiac arrest and sudden death," said trial investigator Vasanth Vedantham, MD, PhD, a professor of medicine, cardiac electrophysiologist, and director of cardiovascular genetics at the University of California, San Francisco. "Unlike existing treatments for ARVC, TN-401 gene therapy seeks to directly address the underlying cause of disease by delivering a fully functional copy of PKP2 to the heart."
ARVC and the Need for New Therapies
PKP2 mutations are the most common single-gene cause of ARVC, affecting an estimated 70,000 people in the U.S. alone. These mutations disrupt the desmosomal complex, leading to fibrofatty replacement of cardiac muscle cells and unstable electrical pulses. Current treatments, including anti-arrhythmic medications, implantable cardioverter-defibrillators, and ablation procedures, do not address the underlying genetic cause.
Tenaya's Broader Pipeline
In addition to TN-401, Tenaya is also developing TN-201, a gene therapy for hypertrophic cardiomyopathy (HCM) caused by mutations in the MYBPC3 gene. The company recently received clearance to move to a higher dose cohort in the MyPeak-1 Phase 1b clinical trial (NCT05836259) evaluating TN-201.
