Post-Marketing Safety of Tazemetostat in Antitumor Therapy: A Real-World Pharmacovigilance Study of the FDA Adverse Event Reporting System.

[BACKGROUND] Tazemetostat is an oral inhibitor of enhancer of zeste homolog 2 (EZH2) and is used for the treatment of epithelioid sarcoma (ES) and follicular lymphoma (FL). In this study, we investigated the adverse events (AEs) of tazemetostat based on real data from the U.S Food and Drug Administration(FDA) Adverse Event Reporting System (FAERS).

[METHODS] To quantify the signals of AEs associated with tazemetostat, we employed disproportionality analyze, including the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms.

[RESULTS] A total of 7,133,678 reports of AEs were collected from the FAERS database, of which 1,110 reports were identified with tazemetostat as the "primary suspect (PS)". A total of 32 significant disproportionality preferred terms(PTs) conforming to the four algorithms were simultaneously retained. There were multiple unexpected AEs caused by tazemetostat that were not mentioned in the label yet, including pleural effusion (ROR = 3.84, PRR = 3.83, IC = 3.83, IBGM = 1.94), lymphadenopathy (ROR = 3.88, PRR = 3.88, IC = 3.87, IBGM = 1.95) and taste disorder(ROR = 20.48, PRR = 20.23, IC = 20.16, IBGM = 4.33). Additionally, the majority of tazemetostat-associated AEs occurred within the first month of treatment initiation ( = 126, 49.8%).

[CONCLUSION] Clinicians need to monitor safety for tazemetostat during the first 30 days and pay more attention to new AE signals.