Tazemetostat for Tumors Harboring SMARCB1/SMARCA4 or EZH2 Alterations: Results from NCI-COG Pediatric MATCH APEC1621C.

Although tazemetostat did not meet its primary efficacy endpoint in this population of refractory pediatric tumors (ORR: 5%, 90% CI 1%, 20%), 25% of patients with multiple histologic diagnoses experienced prolonged stable disease of > 6 months (range: 9-26 cycles), suggesting a potential effect of tazemetostat on disease stabilization.