FDA Expands Mavacamten Label to Pediatric Patients With oHCM

The FDA has expanded the indication for mavacamten (Camzyos; Bristol Myers Squibb) in symptomatic obstructive hypertrophic cardiomyopathy (oHCM) to include pediatric patients, covering adults and children weighing 30 kg (66 lbs) or more, according to a news release from Bristol Myers Squibb. The cardiac myosin inhibitor (CMI) is now the only FDA-approved oHCM therapy for a pediatric population.¹

For pharmacists, the expansion brings the familiar Risk Evaluation and Mitigation Strategy (REMS), echocardiographic monitoring, and drug interaction demands to younger patients, along with a new 1-mg step for pediatric dose reductions.¹

SCOUT-HCM Results

The September 30, 2026, approval is based on the phase 3 SCOUT-HCM trial (NCT06253221), published in The New England Journal of Medicine. Investigators randomly assigned 44 adolescents aged 12 to younger than 18 years with New York Heart Association (NYHA) class 2 or 3 oHCM to mavacamten (n = 23) or placebo (n = 21). Mean baseline Valsalva left ventricular outflow tract (LVOT) gradients were similar (78.4 mm Hg and 80.8 mm Hg, respectively), and background therapy was permitted; most patients were receiving β-blockers.^1,2

At week 28, the least-squares mean change in Valsalva LVOT gradient, the primary end point, was −48.5 mm Hg with mavacamten vs −0.5 mm Hg with placebo (difference, −48.0 mm Hg; 95% CI, −67.7 to −28.3; P < .001). BMS also reported a −47.0 mm Hg between-group difference in resting LVOT gradient, a secondary analysis not adjusted for multiplicity.^1,2

Safety Findings Track With Adult Experience

Adverse event incidence was similar between groups, with 2 patients in each arm experiencing serious adverse events. In the mavacamten group, 1 patient had 2 episodes of syncope, and another received an inappropriate implantable cardioverter-defibrillator shock. No patient's left ventricular ejection fraction (LVEF) fell below 50%, and no deaths occurred.²

The boxed warning for heart failure due to systolic dysfunction remains. LVEF must be assessed by echocardiogram before and during treatment; initiation is not recommended when LVEF is below 55%, and therapy should be interrupted if LVEF falls below 50% or heart failure symptoms emerge. Notably, the indication extends to 30 kg, while BMS states that pediatric safety was evaluated in patients weighing at least 35 kg.¹

In adults, real-world REMS experience has been reassuring. "Overall...it appears like the safety is a little bit better in real-world practice," Andrew Willeford, PharmD, PhD, BCCP, an assistant professor at the University of California–San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences, said in a Pharmacy Times Insights discussion.³

Interactions and Counseling Considerations

Mavacamten is available only through the Camzyos REMS Program, which requires certified prescribers and pharmacies and enrolled patients. The drug is primarily metabolized by CYP2C19 and CYP3A4 and is contraindicated with strong CYP2C19 inhibitors and moderate to strong CYP2C19 or CYP3A4 inducers. When a patient on therapy starts certain CYP2C19 or CYP3A4 inhibitors, the label calls for a 1-level dose reduction, which in pediatric patients can now step from 2.5 mg to 1 mg.¹

The label specifically names OTC omeprazole, esomeprazole, and cimetidine. Laura Velazquez, PharmD, PhC, BCACP, a pharmacist clinician at Presbyterian Heart and Vascular, has called OTC products for gastroesophageal reflux disease (GERD) "notorious offending medications," recommending that pharmacists "preemptively discuss with [patients] if they have GERD and which therapies they can use in the instance of future symptoms."^1,3

Pharmacists should also confirm the absence of pregnancy in females of reproductive potential and advise effective contraception during treatment and for 4 months afterward, because mavacamten may reduce the effectiveness of some combined hormonal contraceptives.¹

"Use pharmacists as your resource to feel secure in what you're taking, whether it's mavacamten or anything else," Willeford said.³

REFERENCES

1. U.S. Food and Drug Administration approves expanded indication for Bristol Myers Squibb's CAMZYOS (mavacamten) for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM) in adults and pediatric patients. News release. Bristol Myers Squibb. September 30, 2026. Accessed October 1, 2026. https://news.bms.com/news/corporate-financial/2026/U-S--Food-and-Drug-Administration-Approves-Expanded-Indication-for-Bristol-Myers-Squibbs-CAMZYOS-mavacamten-for-the-Treatment-of-Symptomatic-Obstructive-Hypertrophic-Cardiomyopathy-oHCM-in-Adults-and-Pediatric-Patients/default.aspx

2. Rossano JW, Canter C, Wolf CM, et al; SCOUT-HCM Investigators. Mavacamten in adolescents with obstructive hypertrophic cardiomyopathy. N Engl J Med. 2026;395(4):362-373. doi:10.1056/NEJMoa2601103

3. Halpern L. How clinical pharmacists optimize obstructive hypertrophic cardiomyopathy care. Pharmacy Times. May 15, 2026. Accessed October 1, 2026. https://www.pharmacytimes.com/view/how-clinical-pharmacists-optimize-obstructive-hypertrophic-cardiomyopathy-care