Bristol Myers Squibb (BMS) has announced positive long-term results from the EXPLORER-LTE extension study of CAMZYOS (mavacamten) in adults with New York Heart Association (NYHA) class II-III symptomatic obstructive hypertrophic cardiomyopathy (oHCM). The data, representing up to 3.5 years of follow-up, confirm the sustained efficacy and safety of CAMZYOS in this patient population.
The EXPLORER-LTE cohort is part of an ongoing five-year, dose-blinded study involving patients who completed the EXPLORER-HCM trial. Participants initially received a 5mg daily dose of CAMZYOS, with adjustments made at weeks four, eight, and twelve based on echocardiographic assessments of Valsalva resting left ventricular outflow tract (LVOT) gradient and left ventricular ejection fraction (LVEF).
Sustained Improvements in Cardiac Function
The results demonstrated consistent and sustained improvements in key echocardiographic measures and biomarkers. These included reductions in resting LVOT gradient, Valsalva LVOT gradient, left atrial volume index, and NT-proBNP levels. These improvements indicate a significant and lasting positive impact on cardiac function in patients treated with CAMZYOS.
Enhanced Functional Capacity and Symptom Relief
In addition to improvements in objective cardiac measures, patients also experienced notable enhancements in functional capacity. A majority of patients progressed to NYHA class I, signifying a reduction in symptoms and an improved ability to perform daily activities. This improvement in functional status underscores the clinical relevance of CAMZYOS in managing oHCM.
Safety Profile Remains Consistent
The long-term safety profile of CAMZYOS remained consistent with previous findings, with no new safety concerns emerging over the 3.5-year follow-up period. Notably, 20 patients experienced transient reductions in LVEF below 50%, but all recovered following treatment interruption, and 14 were able to resume CAMZYOS therapy.
Redefining the Treatment Landscape for oHCM
CAMZYOS is the first cardiac myosin inhibitor approved in the US for adults with NYHA class II-III symptomatic oHCM. This novel mechanism of action targets the underlying cause of the disease, offering a new approach to managing this challenging condition.
According to Roland Chen, head and senior vice-president of immunology, cardiovascular and neuroscience (ICN) development at Bristol Myers Squibb, "These results, representing the longest duration of follow-up of the Phase III EXPLORER study to date, further reinforce the established safety and efficacy profile of CAMZYOS... As the first and only approved cardiac myosin inhibitor for patients with symptomatic obstructive HCM... CAMZYOS... is redefining the treatment landscape for this patient population."
