Five-year EXPLORER-LTE data show sustained LVOT gradient reductions and functional improvements with Camzyos in symptomatic obstructive HCM.
Written By: Dishali Desai, PharmD
Reviewed By: Pharmacally Editorial Team
Bristol Myers Squibb presented five-year data from the EXPLORER-LTE cohort of the MAVA-LTE study (NCT03723655) at the 2026 European Society of Cardiology (ESC) Congress. The results demonstrate that Camzyos (mavacamten) maintained sustained reductions in left ventricular outflow tract (LVOT) obstruction and long-term functional improvements in adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM), with no new safety signals reported.
Five-Year Data: Sustained Reductions in LVOT Obstruction
EXPLORER-LTE is a single-arm, open-label, dose-blinded extension of the Phase 3 EXPLORER-HCM study (NCT03470545). A total of 231 patients who completed EXPLORER-HCM entered the long-term extension.
At Week 252, mean resting LVOT gradient had decreased by 38.7 mmHg from the start of the long-term extension, while the mean Valsalva LVOT gradient had decreased by 55.6 mmHg. Nearly all patients (97.4%) achieved a Valsalva LVOT gradient of ≤30 mmHg, the threshold cited in the study for obstruction in oHCM.
Functional improvements were also sustained. By Week 252, 69.6% of patients had improved by at least one NYHA functional class, while 59.2% were asymptomatic. These findings are clinically relevant in oHCM, where LVOT obstruction can contribute to exertional symptoms and reduced functional capacity.
Echocardiographic findings remained supportive of treatment effect. Mean left ventricular ejection fraction (LVEF) decreased by 10.2% from the beginning of the long-term extension but remained within the normal range. No new safety signals were observed beyond those reported in the primary EXPLORER-HCM study.
Mechanism of Action: Cardiac Myosin Inhibition
Camzyos is a selective, reversible allosteric inhibitor of cardiac myosin. By reducing excessive cardiac contractility, mavacamten lowers LVOT obstruction and cardiac filling pressures in patients with oHCM.
The treatment is approved for adults with symptomatic NYHA class II-III oHCM in the United States and European Union. Its clinical use requires continued cardiac monitoring because reductions in myocardial contractility can affect systolic function.
Real-World Evidence Reinforces Trial Outcomes
Additional presentations at ESC Congress provided data from real-world populations, adding to the evidence base for mavacamten in routine clinical practice.
Two analyses from the global COLLIGO-HCM retrospective study reported reductions in LVOT obstruction and improvements in NYHA class, with effectiveness and safety findings broadly consistent across real-world patient populations. A German observational registry analysis similarly supported improvements in NYHA functional class.
Separate healthcare resource utilization data from Sweden highlighted the broader clinical and healthcare burden associated with HCM and oHCM, reinforcing the importance of accurate diagnosis and consistent disease management.
Long-term evidence adds clinical perspective
Anjali T. Owens, MD, Medical Director of the Center for Inherited Cardiac Disease and Associate Professor of Medicine at the University of Pennsylvania, emphasized the importance of long-term evidence in oHCM, a chronic and progressive condition requiring ongoing treatment and monitoring.
The five-year EXPLORER-LTE findings extend the clinical evidence available for sustained mavacamten treatment, while the real-world analyses provide additional context on how treatment effects translate into routine care.
Safety Profile & REMS Protocol
Despite the durability of the reported clinical improvements, mavacamten treatment requires ongoing assessment of cardiac function. U.S. prescribing information recommends echocardiographic monitoring before and during treatment, with interruption of therapy if LVEF falls below 50% or if heart-failure symptoms or worsening clinical status develop.
Camzyos is also subject to a Risk Evaluation and Mitigation Strategy (REMS) in the United States because of the potential for systolic dysfunction and heart failure. Appropriate monitoring and management of drug interactions remain important components of treatment.
Long-Term Role in oHCM Management
The EXPLORER-LTE results provide five-year evidence of sustained reductions in LVOT gradients and continued functional improvement with Camzyos in symptomatic oHCM. Together with findings from global and regional real-world studies, the data broaden the understanding of long-term treatment effectiveness and safety in clinical practice. Expanding beyond adult populations, mavacamten is also being evaluated in younger cohorts, with Phase 3 SCOUT-HCM trial data demonstrating significant reductions in LVOT obstruction in adolescent patients with symptomatic oHCM.
Currently approved in more than 60 countries and regions, Camzyos remains an established cardiac myosin inhibitor for symptomatic oHCM.
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About the Writer
Dishali Desai (LinkedIn) is a PharmD professional with expertise in clinical pharmacy, evidence-based healthcare writing, and published work on Brugada syndrome and ADR reporting.
Her interests include guideline integration, multimodal therapy, pharmacogenomics, and antibiogram utilization, with a focus on clinical evidence and treatment decisions.
As a healthcare writer, she translates complex clinical information into clear, accurate, and evidence-informed medical content.