New Heart Drug Shows 'Best-in-Class' Potential for Hypertrophic Cardiomyopathy

By Kenneth Walker

SHANGHAI and SAN FRANCISCO – March 30, 2026 – A new investigational drug for a common inherited heart condition is showing significant promise, with new data suggesting it could offer a more effective, safer, and simpler treatment path for thousands of patients. Hengrui Pharma and Braveheart Bio today announced highly positive results from a Phase 2 study of their cardiac myosin inhibitor, HRS/BHB-1893, for patients with obstructive hypertrophic cardiomyopathy (oHCM).

The results, unveiled in a late-breaking presentation at the American College of Cardiology's Annual Scientific Session, suggest the drug could have a 'best-in-class' clinical profile. Treatment with HRS/BHB-1893 led to rapid and substantial reductions in the heart obstruction that defines the disease, all while demonstrating a favorable safety profile and, critically, the potential for a simplified dosing regimen that could set it apart from current therapies.

"We believe these results are consistent with a best-in-class clinical profile, with the potential to become a novel, promising treatment option for patients with obstructive hypertrophic cardiomyopathy," said Travis Murdoch, M.D., Chief Executive Officer and President of Braveheart Bio. He noted that the drug's profile "may address key limitations of current therapies and unlock adoption by a broad population of patients with urgent needs."

A Potential New Era for a Debilitating Disease

Hypertrophic cardiomyopathy (HCM) is a genetic disease affecting approximately 1 in 500 people, making it one of the most common rare diseases. It causes the heart muscle to thicken abnormally, which can lead to debilitating symptoms and life-threatening complications. In about two-thirds of cases, patients have the obstructive form (oHCM), where the thickened muscle blocks blood flow out of the heart's main pumping chamber.

This obstruction forces the heart to work harder, leading to symptoms like severe shortness of breath, chest pain, fatigue, and fainting. The condition can significantly limit a person's ability to perform routine daily activities and carries a risk of heart failure, stroke, and sudden cardiac death, even in young adults and athletes. For decades, treatment has relied on medications like beta-blockers that manage symptoms but don't address the underlying cause, or invasive procedures such as open-heart surgery (septal myectomy) for severe cases.

The development of cardiac myosin inhibitors marked a turning point by directly targeting the overactive heart muscle contractions that drive the disease. HRS/BHB-1893 belongs to this next generation of therapies, and its latest data points toward a significant refinement in this therapeutic approach, promising not just efficacy but also ease of use.

Unpacking the Impressive Clinical Data

The multi-center Phase 2 study (NCT06516068) enrolled 42 patients with symptomatic oHCM. The primary goal was to measure the change in the left ventricular outflow tract gradient (LVOT-G), a direct measure of the obstruction in the heart. The results were striking.

Across different dosing groups, treatment with HRS/BHB-1893 led to a rapid and significant drop in this gradient. A complete response, defined as the gradient falling below the clinically significant threshold of 30 mmHg, was achieved in up to 86% of patients in one cohort. The effect was also swift, with the average gradient falling below this threshold as early as day five of treatment. All 42 patients who completed the initial 12-week study chose to continue treatment in an open-label extension, where the complete response rate reached 88% by week 39.

Perhaps the most crucial finding was the drug's minimal impact on the heart's overall pumping function. A key safety concern with this class of drugs is the potential to reduce the left ventricular ejection fraction (LVEF)—a measure of how much blood the ventricle pumps out with each beat—too much, which could lead to heart failure. In this study, the observed decrease in LVEF was minimal, ranging between just 1.8% and 2.7%, and no patient's ejection fraction dropped below the safety threshold of 55%. This suggests a wide safety margin that could differentiate it from competitors.

Beyond reducing the obstruction, the drug also demonstrated improvements in other key health indicators. In the dose group selected for long-term study, patients showed an increase in peak oxygen uptake (pVO2), a measure of exercise capacity, and a 10.5-point improvement on the Kansas City Cardiomyopathy Questionnaire (KCCQ-CSS), a key measure of quality of life. Furthermore, levels of NT-proBNP, a biomarker for heart stress, were reduced by 88%.

A Simplified Approach in a Complex Field

The data also highlighted a major potential advantage for both patients and clinicians: simplicity. The first approved cardiac myosin inhibitor, Bristol Myers Squibb's Camzyos (mavacamten), while effective, comes with a complex Risk Evaluation and Mitigation Strategy (REMS) program and a boxed warning due to the risk of systolic dysfunction. This requires frequent and careful monitoring of LVEF, creating a significant logistical burden.

The Phase 2 results for HRS/BHB-1893 suggest a far simpler path. The study found that 89% of patients were effectively treated with a 40 mg or 60 mg twice-daily dose, requiring minimal or no dose adjustments. This stability, combined with the minimal impact on LVEF, could potentially eliminate the need for the kind of intensive monitoring required for existing therapies.

"The results of this study build on the clinical data observed to date and reinforce BHB/HRS-1893's potential as a highly differentiated treatment option for patients with oHCM," stated Sheng Qi, M.D., Executive Director and Head of Cardiovascular at Hengrui Pharma.

This potential for a straightforward 'start-and-stay' dosing regimen could make the therapy more accessible, allowing a broader range of cardiologists, not just specialists at dedicated HCM centers, to comfortably prescribe and manage the treatment.

Navigating a Competitive and High-Stakes Market

Braveheart Bio, a clinical-stage biotech backed by a syndicate of top-tier life science investors including a16z Bio + Health and OrbiMed, is entering a competitive but lucrative market. While mavacamten established the class, another competitor, aficamten from Cytokinetics, is also in late-stage development and has shown a favorable safety profile. The success of HRS/BHB-1893 will depend on its ability to clearly differentiate itself in a pivotal Phase 3 trial.

Armed with these compelling Phase 2 results, Braveheart Bio and Hengrui Pharma are moving forward with confidence. Braveheart, which holds the exclusive license for the drug outside of Greater China, plans to initiate a global pivotal clinical study later in 2026. This trial will be the ultimate test of whether the drug's promising efficacy, safety, and simplified dosing hold up in a larger, more diverse patient population. Hengrui is already conducting a separate Phase 3 study in China, underscoring the global ambition for the compound.

If the forthcoming pivotal trials confirm the 'best-in-class' potential seen in this Phase 2 data, HRS/BHB-1893 could not only capture a significant share of the growing HCM market but also fundamentally improve the standard of care, offering a powerful and patient-friendly option for a community long in need of better solutions.