Dr. Chi Discusses Tazemetostat Trial in INI1-Negative Pediatric Tumors

Susan N. Chi, MD, senior physician, director, Pediatric Brain Tumor Clinical Trials Program, Dana-Farber Cancer Institute, assistant professor of pediatrics, Harvard Medical School, discusses a trial of tazemetostat in pediatric patients with INI1-negative tumors.

The EZH2 inhibitor tazemetostat was evaluated in a phase I study of pediatric patients with INI1-negative rhabdoid tumors, epithelioid sarcoma, chordoma, and synovial sarcoma tumors. In the study, 46 patients were treated with 7 dose levels in this dose-escalation portion of the phase I trial, ranging from 240 mg/m² to 1200 mg/m² of tazemetostat given twice daily.

Results presented at the 2018 ASPHO Conference showed that tazemetostat had promising antitumor activity in these patients, with 3 patients achieving a complete response, 1 achieving a partial response, and 5 having stable disease. There was 1 side effect of a secondary T-cell lymphoma. Chi says that they are currently investigating this and are working it up to see what the relationship is, and how it might be preventable in the future. This secondary malignancy led the FDA to halt enrollment in April 2018.