Mavacamten

Hengrui Pharma and Braveheart Bio reported Phase II results for HRS-1893 (BHB-1893), a selective small-molecule cardiac myosin inhibitor, in patients with obstructive hypertrophic cardiomyopathy, the companies said on March 30. The data, from a 42-patient open-label dose-ranging study (NCT06516068), were presented as a late-breaking clinical research session at the American College of Cardiology Annual Scientific Session. Across three dose groups over 12 weeks, HRS-1893 produced complete Valsalva left ventricular outflow tract gradient (LVOT-G) responses — defined as a reduction below 30 mmHg — in 50% to 86% of patients, according to the companies. Mean LVEF declined between 1.8% and 2.7% across groups, and no patient recorded an ejection fraction below 55% during the core study period. The companies reported that average Valsalva LVOT-G fell below 30 mmHg as early as day 5. In Group 2, the 40 mg twice-daily cohort selected for an open-label extension, peak oxygen uptake increased by 1.0 mL/kg/min, the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score improved by 10.5 points, and NT-proBNP declined by 88%. At week 39 of the open-label extension, in which all 42 patients enrolled, the complete LVOT-G response rate was 88%. Adverse events were mild to moderate in severity, and none led to treatment interruption or discontinuation, the companies said. No new safety signals were identified during the 12-week study period. The trial randomized patients 1:1:1 to oral HRS-1893 at 20 mg twice daily (titrated up to 60 mg), 40 mg twice daily (up to 80 mg), or 40 mg once daily (up to 120 mg), with individual dose adjustments permitted based on LVEF and Valsalva LVOT-G assessments. The primary endpoint was change in Valsalva LVOT-G from baseline to week 12. The companies reported that 89% of patients were managed at 40 mg or 60 mg twice daily with minimal or no titration. The study was open-label, and no placebo arm was included, which limits interpretation of the magnitude of observed changes. Efficacy data from the once-daily group and full between-group comparative analyses were not disclosed in detail. The data are based on 42 patients, and the open-label extension findings remain preliminary. HRS-1893 is described by the companies as a selective cardiac myosin inhibitor intended to reduce hypercontractility in hypertrophic cardiomyopathy. The oHCM field already includes Bristol Myers Squibb’s mavacamten, approved by the US FDA in 2022, and aficamten. While cross-trial comparisons should be interpreted cautiously because endpoint definitions and trial designs differ, mavacamten was associated with a 48.1% rate of Valsalva LVOT gradient <30 mmHg at week 30 in EXPLORER-CN, while aficamten achieved a 49.3% rate of Valsalva LVOT gradient <30 mmHg at week 24 in SEQUOIA-HCM. Despite numerically higher response rates, the open-label design and small sample size mean HRS-1893’s apparent efficacy advantage over mavacamten and aficamten remains unproven. HRS-1893 was developed by Hengrui, with rights licensed outside of Greater China licensed to Braveheart in a September 2025 deal. Hengrui is leading a strong clinical development program, with a dose finding Phase II in symptomatic oHCM already completed, an ongoing Phase II in nHCM, and an ongoing Phase III study in oHCM in China (NCT07021976). Your email address will not be published. Required fields are marked * Comment * Name * Email * Website

The heart drug that Braveheart Bio licensed from China’s Jiangsu Hengrui Pharmaceuticals has shown promise in a mid-stage trial, according to data released Monday. The pill is intended to treat obstructive hypertrophic cardiomyopathy (oHCM), a disease in which the heart muscle thickens and creates a blockage that impairs the organ’s ability to pump blood. The drug, called BHB-1893 or HRS-1893, is a cardiac myosin inhibitor (CMI), like Bristol Myers Squibb’s Camzyos and Cytokinetics’ newly approved Myqorzo. In an open-label study run by Hengrui in China, 42 patients given Braveheart’s drug were found to have less difficulty pumping blood out of the heart’s left ventricle, as shown by reductions in a measure known as left ventricular outflow tract gradient (LVOT-G). Between 50% and 86% of the patients got to normal LVOT-G levels after three months’ treatment with the drug. The 86% response was seen with the middle dose tested in the trial. “We are seeing very rapid and deep normalization of the gradient that forms in this disease [which] is one of the key things that drives symptoms, and ultimately heart failure, in these patients,” Braveheart CEO Travis Murdoch told Endpoints News . The data were released at the American College of Cardiology’s annual meeting. All the patients then entered an extension period, and after roughly nine months, 88% of the patients had a normal LVOT-G level. “That, to us, is an impressive result, one that speaks to potential differentiation,” Murdoch said. Braveheart bought its rights to the drug last September , in a deal worth $65 million in upfront cash and stock, plus a large set of incentives worth as much as $1.01 billion. Hengrui will keep the rights in Greater China, while Braveheart has the rest of the world. BHB/HRS-1893 is already in a Hengrui-run China-based Phase 3 trial, using a dose of up to 80 mg. Murdoch said that historically there has been a high degree of consistency in terms of how patients respond to CMI therapy. This could suggest that the data could be relevant globally. But the FDA has been reluctant to accept China-only trial data. Braveheart is aiming to kick off its own Phase 3 in the US this year. The coming late-stage data might have implications for Braveheart as a company. Murdoch has already sold the immunology-focused company HI-Bio to Biogen for $1.15 billion in 2024. “HI-Bio was a great, great partnership we ultimately had with Biogen,” Murdoch said. But no deal is imminent for Braveheart, it seems, with Murdoch pointing out how well-funded the company is. Since HCM is an orphan indication, the company believes it can market the drug alone. “We believe we can take [it] all the way. Certainly we’re planning for that, and we’ll see what the future holds,” Murdoch said. That will mean taking on Bristol Myers and Cytokinetics, so any advantage will count. Murdoch said he doesn’t think BHB/HRS-1893 will have worries about drug-drug interactions, a concern with Camzyos, though not with Myqorzo. Braveheart’s chief scientific officer Marc Evanchik points to the drug’s swift action as another differentiating factor, with the effect on outflow tract gradient manifesting within a few days. “That is game-changing in this industry, because the current agents are taking weeks to months to titrate to an effective dose,” he said, crediting the drug’s pharmacokinetic profile. “We don’t believe all CMIs are built the same. We think this one’s got deeper effects on efficacy and enhanced safety.” None of the patients in the trial paused or quit treatment because of side effects. And importantly, none of the patients saw their left ventricular ejection fraction — another marker of the heart’s pumping ability — fall below 55%. This is a limiting factor in the use of Camzyos and Myqorzo; dosing with these drugs must be reduced or stopped if a patient’s ejection fraction drops below 50%. BHB/HRS-1893 should also have data coming in a different form of the disease — non-obstructive HCM, in which there is no blockage in the heart, but pumping ability is still diminished. About a third of patients with HCM have the non-obstructive form. A China-based Phase 2 study of BHB/HRS-1893 in non-obstructive HCM should read out by midyear. Notably, Camzyos’ pivotal trial in this condition failed . A pivotal trial of Myqorzo in nHCM is due to yield data in the coming months.