Bristol Myers Squibb (NYSE: BMY) reported five-year data from the EXPLORER-LTE cohort of the MAVA-LTE study showing that mavacamten (Camzyos) sustained reductions in left ventricular outflow tract (LVOT) obstruction and functional improvement in symptomatic obstructive hypertrophic cardiomyopathy (oHCM), with no new safety signals identified over the follow-up period. The data, presented at the European Society of Cardiology (ESC) Congress 2026 in Munich, extend Camzyos' longitudinal efficacy and safety record as the drug faces its first direct cardiac myosin inhibitor competitor, Cytokinetics' aficamten (Myqorzo).
The EXPLORER-LTE study (NCT03723655) is a single-arm, open-label, dose-blinded extension of the Phase III EXPLORER-HCM trial, enrolling 231 patients from the US, Europe, and Israel who had completed the parent study. At 252 weeks, mean changes from baseline at initiation of the long-term extension were -38.7 mm Hg for resting LVOT gradient and -55.6 mm Hg for Valsalva LVOT gradient. Nearly all patients (97.4%) achieved a Valsalva LVOT gradient of 30 mm Hg or below. Functional class improvements were also sustained: 69.6% of patients improved by at least one New York Heart Association (NYHA) class, and 59.2% were asymptomatic at the 252-week timepoint. Mean left ventricular ejection fraction (LVEF) decreased from baseline but remained within the normal range. Bristol Myers Squibb (NYSE: BMY) reported that safety findings were consistent with those from the primary EXPLORER-HCM study, with no new signals identified.
Mavacamten is a selective, reversible, allosteric inhibitor of cardiac myosin ATPase that shifts myosin heads toward an energy-conserving, sequestered state, reducing excessive sarcomere contractility and thereby lowering LVOT obstruction and cardiac filling pressures. The drug carries a US FDA Risk Evaluation and Mitigation Strategy (REMS) requirement due to the risk of heart failure from systolic dysfunction, necessitating regular echocardiographic monitoring of LVEF.
Complementary presentations at ESC Congress from COLLIGO-HCM, a global retrospective real-world data study, reported effectiveness and safety findings consistent with the clinical trial profile, including symptom improvement and LVOT obstruction reduction across patient populations. A Swedish healthcare resource utilization study was also presented, addressing the broader disease burden of hypertrophic cardiomyopathy (HCM) and oHCM specifically**.**