Mavacamten Monotherapy in Real-World Patients With Obstructive Hypertrophic Cardiomyopathy: Evidence From COLLIGO-HCM.

backgroundMavacamten has been shown to improve cardiac function and symptoms in patients with symptomatic (New York Heart Association class II-III) obstructive hypertrophic cardiomyopathy (HCM). Clinical studies suggest that mavacamten monotherapy is efficacious and has a favorable safety profile, but limited evidence exists regarding monotherapy in real-world studies. This analysis aimed to describe the effectiveness and safety outcomes of mavacamten monotherapy in the real-world COLLIGO-HCM study (Mavacamten ObservationaL Evidence Global Consortium in Hypertrophic Cardiomyopathy).

methodsPatient-level data recorded between April 2022 and February 2025 at 7 sites across 5 countries were extracted. Adult patients with a diagnosis of HCM from 2018 onwards were eligible for inclusion if they had ≥1 mavacamten prescription after the date of diagnosis. Patients were categorized based on background therapy status during mavacamten treatment: mavacamten monotherapy or mavacamten with background therapy (down-titration or no dose modification).

resultsOverall, 278 patients were included and received mavacamten (mavacamten monotherapy, n=88; mavacamten with background therapy, n=190). At month 9, most patients achieved ≥1 New York Heart Association class improvement from baseline (mavacamten monotherapy, 60.0%; mavacamten with background therapy, 61.0%). Improvements in resting and Valsalva left ventricular outflow tract gradients from baseline to month 9 were observed in both subgroups; mean left ventricular ejection fraction through month 9 remained ≥62.0% with mavacamten monotherapy and ≥61.4% with mavacamten with background therapy. Two patients in the mavacamten monotherapy subgroup and 1 patient in the mavacamten with background therapy subgroup permanently discontinued treatment owing to left ventricular ejection fraction <50%.

conclusionsMavacamten monotherapy was associated with improvements in cardiac function and symptoms, and positive benefits to the risk profile over a 9-month follow-up period; this was consistent with improvements observed in patients treated with mavacamten with background therapy. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT06372457.