Pharmaceutical company Hengrui Pharma and Braveheart Bio, a late clinical-stage biotechnology company developing novel therapeutics for hypertrophic cardiomyopathy and related conditions, on Monday reported results from a multi-centre, randomised, open-label Phase 2 dose-ranging study evaluating HRS-1893 (also known as BHB-1893), an investigational next-generation cardiac myosin inhibitor, in patients with obstructive hypertrophic cardiomyopathy (oHCM).

According to the companies, in the 42-patient study, HRS-1893 treatment resulted in rapid and substantial reductions in left ventricular outflow tract gradient (LVOT-G), an established measure of cardiac obstruction.

The study of 42 patients was designed to measure efficacy and safety of BHB/HRS-1893 and to evaluate dose regimen options that could shorten the time to an effective dose.

BHB/HRS-1893 treatment resulted in rapid and substantial reductions in LVOT-G with minimal change in left ventricular ejection fraction (LVEF) across dose groups. All 42 patients enrolled in the open-label extension (OLE) part of the study and continued to receive administration of BHB/HRS-1893. At Week 39 of the OLE, the complete Valsalva LVOT-G response rate was 88%.

Additionally, BHB/HRS-1893 was generally well tolerated, and no new safety signals were identified in the 12-week study period. Study results were highlighted in a late-breaking featured clinical research presentation at the American College of Cardiology's Annual Scientific Session & Expo.