Bristol Myers Squibb reports positive Phase 3 SCOUT-HCM results showing Camzyos (mavacamten) significantly reduced LVOT gradient and improved clinical outcomes in adolescents with obstructive hypertrophic cardiomyopathy.
Written By: Pharmacally Medical News Desk
Bristol Myers Squibb announced positive topline results from SCOUT-HCM, a Phase 3 clinical trial evaluating Camzyos (mavacamten) in adolescents aged 12 years to under 18 years with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). This marks the first Phase 3 study of a cardiac myosin inhibitor in an adolescent oHCM population.
The trial met its primary endpoint, showing a statistically significant reduction from baseline in Valsalva left ventricular outflow tract (LVOT) gradient at Week 28 compared with placebo. Multiple secondary endpoints assessing clinically meaningful aspects of oHCM were also met, supporting the potential of Camzyos to improve cardiac obstruction, symptoms, and functional status in this younger population.
Cristian Massacesi, MD, Executive Vice President, Chief Medical Officer and Head of Development at Bristol Myers Squibb, stated that adolescent oHCM is a serious and rare disease associated with substantial morbidity and mortality. He noted that the SCOUT-HCM results highlight the potential for Camzyos to become the first cardiac myosin inhibitor for adolescents with oHCM, building on its established impact in adults, with more than 20,000 patients initiated on therapy in the U.S.
About Camzyos (mavacamten)
Camzyos is a selective, reversible cardiac myosin inhibitor and the most extensively studied agent in the cardiac myosin inhibitor (CMI) class. It targets the underlying pathophysiology of hypertrophic cardiomyopathy by reducing excessive myosin-actin cross-bridge formation within the cardiac sarcomere.
In obstructive HCM, hypercontractility of the heart muscle leads to dynamic LVOT obstruction and impaired ventricular filling. By modulating myosin activity, Camzyos reduces hypercontractility, lowers LVOT gradients, improves cardiac filling pressures, and translates these physiological effects into symptom relief and improved exercise capacity.
SCOUT-HCM Clinical Trial
SCOUT-HCM (NCT06253221) is a randomized, double-blind, placebo-controlled international Phase 3 trial that enrolled 44 adolescents aged 12 to under 18 years with symptomatic oHCM.
The SCOUT-HCM trial was designed as a randomized, double-blind, placebo-controlled international Phase 3 study with a total planned duration of up to 200 weeks. The study included an initial 28-week placebo-controlled treatment period, followed by a 28-week active-treatment crossover phase in which patients originally assigned to placebo transitioned to Camzyos. After completion of these phases, participants were eligible to enter an open-label long-term extension period lasting up to 144 weeks to further assess durability of efficacy and long-term safety.
Primary endpoint of the study was to change from baseline to Week 28 in Valsalva LVOT gradient. The study met its primary endpoint, demonstrating a statistically significant reduction in Valsalva LVOT gradient at Week 28 versus placebo, indicating effective relief of LVOT obstruction.
Statistical significance was achieved across multiple secondary endpoints, supporting clinically meaningful improvements in disease-related outcomes.
Safety Profile
Safety results in adolescents were consistent with the established adult safety profile of Camzyos, with no new safety signals identified in this younger population.
For complete U.S. Prescribing Information, including the Boxed Warning, contraindications, warnings and precautions, and use in specific populations such as pregnancy and lactation, please refer to the official CAMZYOS Prescribing Information available at: https://packageinserts.bms.com/pi/pi_camzyos.pdf
Joseph Rossano, MD, Principal Investigator of SCOUT-HCM and Chief of the Division of Cardiology at Children’s Hospital of Philadelphia, emphasized the importance of the trial in Pediatric cardiology. He highlighted that treatment options for adolescents with oHCM are currently limited to medical symptom management or invasive procedures and described the results as highly encouraging for the field if approved by regulators.
Bristol Myers Squibb plans to present detailed SCOUT-HCM data at an upcoming medical congress and will engage with global health authorities to discuss the results. The study continues with active treatment and long-term extension periods to further evaluate durability of benefit and long-term safety in adolescents.
About Obstructive Hypertrophic Cardiomyopathy in Adolescents
Obstructive hypertrophic cardiomyopathy is a primary cardiac disorder often linked to genetic defects in sarcomeric proteins. In adolescents, oHCM is associated with reduced exercise tolerance, significant symptom burden, and long-term morbidity.
References
Bristol Myers Squibb Announces Positive Topline Results from Phase 3 SCOUT-HCM Trial Evaluating Camzyos (mavacamten) in Adolescents with Symptomatic Obstructive Hypertrophic Cardiomyopathy (oHCM), 12 January 2026, Bristol Myers Squibb – Bristol Myers Squibb Announces Positive Topline Results from Phase 3 SCOUT-HCM Trial Evaluating Camzyos (mavacamten) in Adolescents with Symptomatic Obstructive Hypertrophic Cardiomyopathy (oHCM)
A Study to Evaluate Mavacamten in Adolescents with Symptomatic Obstructive Hypertrophic Cardiomyopathy, ClinicalTrials.gov ID NCT06253221, Study Details | NCT06253221 | A Study to Evaluate Mavacamten in Adolescents With Symptomatic Obstructive Hypertrophic Cardiomyopathy | ClinicalTrials.gov
Rossano J, Canter C, Wolf C, Favatella N, Lockman J, Puli S, Javidialsaadi A, Dyme J, Crevar C, Mital S. Mavacamten in symptomatic adolescent patients with obstructive hypertrophic cardiomyopathy: design of the phase 3 SCOUT-HCM trial. Am Heart J. 2026 Feb;292:107283. Epub 2025 Sep 30. PMID: 41038603. https://doi.org/10.1016/j.ahj.2025.107283
CAMZYOS® (mavacamten), Highlight of Prescribing Information, https://packageinserts.bms.com/pi/pi_camzyos.pdf