Bristol Myers Squibb has reported positive topline results from SCOUT-HCM, a Phase 3 trial evaluating Camzyos (mavacamten) in adolescents with obstructive hypertrophic cardiomyopathy (oHCM).
This is the first Phase 3 study of a cardiac myosin inhibitor conducted in adolescent patients.
SCOUT-HCM: Trial at a Glance
SCOUT-HCM evaluated Camzyos in patients aged 12 to under 18 years with symptomatic oHCM.
Key design elements:
- Phase 3, randomized, double-blind, placebo-controlled
- 44 adolescent patients enrolled globally
- Placebo-controlled period of 28 weeks
- Long-term extension up to 200 weeks
Primary Endpoint Met
The trial met its primary endpoint. Camzyos demonstrated:
- A statistically significant reduction in Valsalva left ventricular outflow tract (LVOT) gradient
- Improvement versus placebo at Week 28
This confirms meaningful reduction in LVOT obstruction.
Positive Secondary Outcomes
Multiple secondary endpoints also achieved statistical significance. These included:
- Resting and post-exercise LVOT gradients
- Peak oxygen consumption
- Symptoms and health status measures
The results point to clinically meaningful disease improvement.
Safety Profile Consistent With Adults
Safety outcomes aligned with existing Camzyos data.
Key observations:
- Safety profile consistent with adult studies
- No new safety signals identified
- Well tolerated in the adolescent population
The study continues into active treatment and long-term extension phases.
Why This Matters for Adolescent oHCM?
Adolescent oHCM is rare, serious, and underserved.
Current treatment limitations include:
- Symptom-focused medical management
- Side effects from beta-blockers
- Risks associated with invasive surgery
There are no FDA-approved therapies that directly target disease biology in adolescents.
Expert Perspectives
Bristol Myers Squibb highlighted the broader impact of the results.
- Camzyos has already transformed adult oHCM care
- Over 20,000 adult patients have started therapy in the US
- The company now sees a path to address adolescent disease
Paediatric cardiology leaders emphasized the rarity of positive Phase 3 data in this population.
Camzyos: A First-in-Class Therapy
Camzyos is a selective, reversible cardiac myosin inhibitor.
Its mechanism:
- Reduces excess myosin–actin cross-bridges
- Decreases hypercontractility
- Improves cardiac filling pressures
The drug targets the root cause of oHCM, not just symptoms.
Regulatory and Next Steps
Bristol Myers Squibb plans to:
- Present full data at an upcoming medical congress
- Engage with global health authorities on next steps
Camzyos is already approved in 50+ countries for adults with symptomatic oHCM.
Bottom Line
SCOUT-HCM marks a major milestone in paediatric cardiology. For the first time, a cardiac myosin inhibitor has shown Phase 3 efficacy in adolescents with oHCM.
If approved, Camzyos could reshape treatment options for this high-risk, underserved patient group.
