A Real‑World Pharmacovigilance Study of FDA Adverse Event Reporting System (FAERS) for Mavacamten

Background: Mavacamten is a first-in-class cardiac myosin inhibitor approved by the US Food and Drug Administration (FDA) for symptomatic obstructive hypertrophic cardiomyopathy (HCM). This pharmacovigilance study aimed to assess mavacamten-related adverse drug reactions (ADRs) in the real world as reported in the FDA Adverse Event Reporting System (FAERS).

Methods: We conducted disproportionality analyses with four signal detection algorithms-reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network, and the multi-item gamma Poisson shrinker to identify mavacamten-related ADRs.

Results: Out of 4,500,131 reports from the FAERS database, 1004 mavacamten-related ADRs were identified from 1 January 2022 to 30 September 2023. A total of 26 significant disproportionality preferred terms (PTs) conforming to the four signal detection algorithms were noted. Some of the statistically significant cardiac ADRs at PT level include decreased ejection fraction (EF) [ROR 33.60 (95% confidence interval, CI 21.79-51.82), PRR 32.86 (χ² 615.96), information component (IC) 5.03, IC025 4.61, empirical Bayesian geometric mean (EBGM) 32.77, EBGM05 21.25], cardiac failure [ROR 9.39 (95% CI 6.49-13.60), PRR 9.13 (χ² 202.42), IC 3.19, IC025 2.83, EBGM 9.12, EBGM05 6.30], and atrial fibrillation [ROR 16.63 (95% CI 12.72-21.75), PRR 15.66 (χ² 769.93), IC 3.97, IC025 3.71, EBGM 15.64, EBGM05 11.96].

Conclusions: The results of our study were consistent with the safety data of clinical trials, including reduced ejection fraction, atrial fibrillation, dyspnea, and syncope. We also found potential new and unexpected ADR signals, such as urinary tract infection, gout, and peripheral edema.