Mavacamten Sustains Symptom, Obstruction Benefits at 5 Years

Mavacamten (Camzyos; Bristol Myers Squibb [BMS']) sustained reductions in left ventricular outflow tract obstruction and improvements in functional class through 5 years of treatment, according to data from the EXPLORER-LTE cohort of the MAVA-LTE study (NCT03723655) presented in a late-breaking session at the European Society of Cardiology (ESC) Congress 2026 in Munich, Germany. The data adds to the long-term evidence for mavacamten in adults with symptomatic obstructive hypertrophic cardiomyopathy (oHCM). BMS described EXPLORER-LTE as the largest and longest evaluation of symptomatic oHCM patients treated with mavacamten.¹

“The EXPLORER-LTE data up to five years reflect the sustained and clinically meaningful effects of Camzyos for patients living with symptomatic oHCM,” Anjali T. Owens, MD, medical director of the Center for Inherited Cardiac Disease and an associate professor of medicine at the Perelman School of Medicine at the University of Pennsylvania, said in a statement. “For a chronic, progressive condition that requires ongoing treatment and monitoring, long-term evidence is essential to helping clinicians better understand how a therapy may benefit patients over time.”

EXPLORER-LTE is a single-arm, open-label, dose-blinded extension of the phase 3 EXPLORER-HCM trial. A total of 231 patients who completed the parent study in the United States, Europe, and Israel enrolled in the extension. Mavacamten is a selective, reversible, allosteric inhibitor of cardiac myosin that targets the hypercontractility underlying oHCM. In the United States, it is indicated for adults with symptomatic New York Heart Association (NYHA) class II-III oHCM to improve functional capacity and symptoms.

Obstruction and Functional Class Improvements Persisted Through 252 Weeks

At 252 weeks, mean changes from the extension study baseline were −38.7 mm Hg for the resting left ventricular outflow tract (LVOT) gradient and −55.6 mm Hg for the Valsalva LVOT gradient. Nearly all patients (97.4%) achieved a Valsalva LVOT gradient of 30 mm Hg or less. Additionally, 69.6% of patients improved by at least 1 NYHA functional class, and 59.2% were asymptomatic at the latest assessment. Mean left ventricular ejection fraction (LVEF) decreased by 10.2% from baseline but remained within the normal range. No new safety signals were identified beyond those observed in the original EXPLORER-HCM trial.

The 5-year results extend earlier interim findings from the same cohort. In the 2024 analysis published in the JACC: Heart Failure, 231 patients enrolled in MAVA-LTE, and among the 206 patients assessed at week 48, 67.5% had improved by at least 1 NYHA functional class. Resting and Valsalva LVOT gradients decreased by a mean of 35.6 mm Hg and 45.3 mm Hg, respectively, while N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels also declined. Benefits in LVOT gradients and NT-proBNP were sustained through 84 weeks among patients who reached that time point.²

The earlier analysis also identified important safety considerations associated with mavacamten. Twelve patients (5.2%) experienced transient reductions in site-read LVEF to below 50%, resulting in temporary treatment interruption; all recovered. Eight patients experienced an adverse event of cardiac failure, and 21 experienced atrial fibrillation. These findings underscore the importance of the echocardiographic monitoring required during treatment.

Real-World Data From COLLIGO-HCM and Registry Studies

Beyond EXPLORER-LTE, BMS presented additional analyses from COLLIGO-HCM, a global retrospective real-world study.¹ The company reported that mavacamten's effectiveness and safety profile in routine clinical practice was consistent across patient groups, including improvements in symptoms and reductions in LVOT obstruction.

A complementary analysis from a German real-world observational registry reported reductions in NYHA class consistent with previously reported real-world studies. An analysis of health care resource utilization in Sweden examined the broader burden of hypertrophic cardiomyopathy and oHCM and highlighted the importance of accurate diagnosis and consistent care.

“For people living with symptomatic oHCM, long-term and real-world evidence provides greater confidence in treatment decisions and a clearer understanding of what sustained therapy may mean over time,” said Cristian Massacesi, MD, executive vice president, chief medical officer, and head of development, BMS, in a statement. “As part of our dedication to advancing cardiovascular research, the data presented at ESC Congress add to the understanding and trust of Camzyos and its role in helping patients manage oHCM, a serious condition affecting daily activities for many patients.”

Managed Care Implications

For payers and health systems managing patients with oHCM, the 5-year EXPLORER-LTE findings provide longer-term evidence of sustained reductions in LVOT gradients and improvements in NYHA functional class with mavacamten. The treatment's ongoing echocardiographic monitoring requirements and availability through the CAMZYOS REMS Program remain important considerations for care delivery and access.

References

1. Bristol Myers Squibb presents data up to 5 years reinforcing the long-term efficacy and safety of Camzyos (mavacamten) in symptomatic obstructive hypertrophic cardiomyopathy (oHCM) at the European Society of Cardiology (ESC) Congress 2026. Bristol Myers Squibb. News release. August 29, 2026. Accessed September 1, 2026. https://news.bms.com/news/details/2026/Bristol-Myers-Squibb-Presents-Data-Up-to-Five-Years-Reinforcing-the-Long-Term-Efficacy-and-Safety-of-Camzyos-mavacamten-in-Symptomatic-Obstructive-Hypertrophic-Cardiomyopathy-oHCM-at-the-European-Society-of-Cardiology-ESC-Congress-2026/default.aspx
2. Rader F, Oręziak A, Choudhury L, et al. Mavacamten treatment for symptomatic obstructive hypertrophic cardiomyopathy: interim results from the MAVA-LTE study, EXPLORER-LTE cohort. JACC Heart Fail. 2024;12(1):164-177. doi:10.1016/j.jchf.2023.09.028