Precision Medicine Breakthrough: Mavacamten Markedly Reduces Heart Obstruction in Teens with Hypertrophic Cardiomyopathy

Children's Hospital of Philadelphia findings offer hope for pediatric cardiac patients and their families

Mar. 29, 2026 at 4:28pm

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Researchers at Children's Hospital of Philadelphia (CHOP) reported that adolescents with hypertrophic cardiomyopathy (HCM) who took mavacamten experienced reduced obstruction, allowing blood to flow more easily from the heart. The research, presented at the American College of Cardiology's Annual Scientific Session and published in the New England Journal of Medicine, is the first to assess the drug in adolescents, who typically have more severe disease.

Why it matters

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and can cause serious complications like chest pain, dizziness, shortness of breath, and even sudden cardiac death. Treatment options have been limited to symptom-focused medications or invasive surgery, so this drug could offer a transformative, precision medicine approach as the first pediatric-specific targeted therapy for this condition.

The details

In the study, 44 teens (ages 12 to <18) with symptomatic obstructive HCM were enrolled at global trial sites. Of those, 23 participants randomly received mavacamten and 21 received a placebo for 28 weeks. Patients taking mavacamten experienced a significant drop in the blockage leaving the heart (about 48.5 mm Hg) compared with almost no change (0.5 mm Hg) in the placebo group. Side effects were similar in both groups, and all patients met a key safety threshold.

  • The research was presented on March 29, 2026 at the American College of Cardiology's Annual Scientific Session in New Orleans.
  • The findings were also published on March 29, 2026 in the New England Journal of Medicine.

The players

Children's Hospital of Philadelphia (CHOP)

A non-profit, charitable organization that was founded in 1855 as the nation's first pediatric hospital. CHOP is known for its long-standing commitment to providing exceptional patient care, training new generations of pediatric healthcare professionals, and pioneering major research initiatives.

Joseph Rossano, MD, MS

The study's lead author and Chief of the Division of Cardiology at Children's Hospital of Philadelphia. Dr. Rossano has cared for children with obstructive hypertrophic cardiomyopathy for decades.

Bristol Myers Squibb

The pharmaceutical company that supported this study of mavacamten, a medication that reduces myosin activity to improve cardiac function.

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What they’re saying

“I've cared for children with obstructive hypertrophic cardiomyopathy for decades, and treatment options have been limited to symptom-focused medications or invasive surgery. If this drug receives FDA approval for teens, it could offer a transformative, precision medicine approach as the first pediatric-specific targeted therapy for this condition.”

— Joseph Rossano, MD, MS, Lead Author and Chief of the Division of Cardiology at Children's Hospital of Philadelphia

“These results are encouraging as they suggest the drug might help the heart heal, changing the patient's underlying biology over time instead of just relieving symptoms. If these findings are confirmed with further research, we'll want to look at starting treatment in children sooner, before the heart has experienced years of damage.”

— Joseph Rossano, MD, MS, Lead Author and Chief of the Division of Cardiology at Children's Hospital of Philadelphia

What’s next

If the findings are confirmed with further research, the next step would be to seek FDA approval for the use of mavacamten in treating adolescents with hypertrophic cardiomyopathy.

The takeaway

This study represents a significant breakthrough in the treatment of hypertrophic cardiomyopathy, a serious and often debilitating heart condition that primarily affects children and adolescents. The potential for mavacamten to not only relieve symptoms but also potentially reverse underlying heart damage offers hope for a new era of precision medicine in pediatric cardiology.