Tenaya Therapeutics has dosed the first subject in the Phase Ib MyPeak-1 clinical trial of TN-201 gene therapy to treat Myosin Binding Protein C3 (MYBPC3)-associated hypertrophic cardiomyopathy (HCM).

The dose-escalating, open-label, multi-centre study is being carried out at up to 12 US centres specialising in HCM care, with the first site being the Hypertrophic Cardiomyopathy Center at the Cleveland Clinic in Ohio.

It will assess the clinical efficacy, tolerability and safety of a one-time intravenous infusion of the adeno-associated virus (AAV)-based gene therapy TN-201.

Initially, the trial intends to enrol at least six symptomatic adults with MYBPC3-associated nonobstructive HCM and have an implantable cardioverter defibrillator.

In total, up to 15 subjects from and outside the US will receive the treatment.

A dose associated with near-maximal efficacy of 3E13vg/kg, obtained through preclinical studies, is used as the first dose and will be evaluated in the study.

Once three patients receive the dosage, a data safety and monitoring board (DSMB) of external advisors will review the safety data.

DSMB will then advise Tenaya to further enrol patients who will receive the dose level of 6E13vg/kg in the initial dose cohort.

Initial data from the trial is anticipated next year.

Tenaya chief medical officer Whit Tingley said: “We are grateful for the support of study sites, referral centres, patient advocacy organisations and patients and families who are actively engaged with Tenaya in our efforts to explore the potential of TN-201 as a novel treatment for MYBPC3-associated HCM.

“We look forward to continuing this close partnership as we enrol additional patients in the MyPeak-1 study and in subsequent studies.”

TN-201 delivers a full-length copy of the human MYBPC3 gene to heart muscle cells to restore normal levels of myosin-binding protein.