Dr. Chi Discusses Pediatric Atypical Teratoid Rhabdoid 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 pediatric atypical teratoid rhabdoid tumors (ATRTs).

ATRTs are rare central nervous system tumors, explains Chi. This tumor is distinct, as it only has 1 specific mutation in its DNA in a gene called INI1 or SMARCB1. Rhabdoid tumors of the kidney and of the soft tissues have a very similar type of mutation, Chi says. Other tumor types in this category include epithelioid sarcoma, renal cell medullary carcinoma, and chordomas.

The EZH2 inhibitor tazemetostat is currently being investigated in pediatric patients with INI1-negative rhabdoid tumors, epithelioid sarcoma, chordoma, and synovial sarcoma tumors. Patients in the phase I dose-escalation portion of the study were treated with 7 dose levels, ranging from 240 mg/m² to 1200 mg/m² of tazemetostat given twice daily. So far, antitumor activity has been shown with tazemetostat in these patients.