Background: oHCM is characterized by mutations in sarcomeric proteins. Mavacamten is a small-molecule modulator of cardiac myosin, commonly affected in oHCM.
Study design: Open-label, nonrandomized phase 2 trial.
Setting: Five academic medical centers.
Synopsis: A total of 21 patients with oHCM were randomized to cohort A, high-dose mavacamten without additional therapy (beta-blockers, CCBs), or cohort B, low-dose mavacamten plus additional medical therapy. The LVOT gradient at 12 weeks improved in both cohorts: Cohort A had a mean change of –89.5 mm Hg (95% confidence interval, –138.3 to –40.7; P = .008) and cohort B –25.0 mm Hg (95% CI, –47.1 to –3.0, P = .020).
Bottom line: This phase 2 trial provides proof of concept and identified a plasma concentration of mavacamten needed to decrease the LVOT significantly. Phase 3 trials hold significant promise.
Citation: Heitner SB et al. Mavacamten treatment for obstructive hypertrophic cardiomyopathy: A clinical trial. Ann Intern Med. 2019 Apr 30..
Dr. Blount is a hospitalist at the University of Colorado at Denver, Aurora.