This is a randomized, double-blind, placebo-controlled, parallel-group, international, Phase 3 study in patients with newly diagnosed H3 K27M-mutant diffuse glioma to assess whether treatment with ONC201 following frontline radiotherapy will extend overall survival and progression-free survival in this population. Eligible participants will have histologically diagnosed H3 K27M-mutant diffuse glioma and have completed standard frontline radiotherapy.
Participants ≥ 52.5 kg will receive 625 mg of ONC201 (5 × 125-mg capsules) dosing days; participants \< 52.5 kg will receive a dose (and corresponding number of capsules) scaled by body weight and rounded to 125-mg increments.
Participants ≥ 52.5 kg will receive 625 mg of ONC201 (5 × 125-mg capsules) or matching placebo on dosing days; participants \< 52.5 kg will receive a dose (and corresponding number of capsules) scaled by body weight and rounded to 125-mg increments
Participants will receive placebo (same number of capsules as the ONC201 dose) on dosing days