Astrocytoma, IDH-Mutant, Grade 2

This phase I trial tests the safety, side effects, and best dose of triapine in combination with radiation therapy in treating patients with glioblastoma or astrocytoma that has come back after a period of improvement (recurrent). Triapine may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Radiation therapy uses high energy x-rays, particles, or radioactive seeds to kill cancer cells and shrink tumors. Giving triapine in combination with radiation therapy may be safe, tolerable, and/or effective in treating patients with recurrent glioblastoma or astrocytoma.

This study will include up to 40 participants with Grade 2 or Grade 3 IDH1-mutant glioma who have undergone surgery and received vorasidenib as their only treatment, experienced radiographic disease progression on vorasidenib (confirmed by Blinded Independent Central Review \[BICR\] per modified Response Assessment in Neuro-Oncology \[RANO\] 2.0), and are not in need of immediate chemotherapy or radiotherapy.

This is a Phase 3, randomized, double-blind, placebo-controlled, multicenter study comparing the efficacy and safety of safusidenib versus placebo in participants with residual or recurrent Grade 2 glioma (oligodendroglioma or astrocytoma) with an IDH1 mutation who have undergone surgery as their only treatment and are not in need of immediate chemotherapy or radiotherapy.

This is a 3-part study. The purpose of Part 1 of the study is to evaluate the efficacy, safety, and pharmacokinetic (PK) characteristics of safusidenib in participants with recurrent/progressive IDH1-mutant World Health Organization (WHO) Grade 2 or Grade 3 glioma. The purpose of Part 2 will be to evaluate the efficacy of maintenance safusidenib treatment versus placebo in IDH1-mutant Grade 2 or Grade 3 astrocytoma with high-risk features or IDH1-mutant Grade 4 astrocytoma, following standard-of-care radiation or chemoradiation and adjuvant temozolomide. Part 2 will be randomized, double-blind, and placebo-controlled. The purpose of Part 3 will be to evaluate the efficacy of safusidenib in participants with residual or recurrent IDH1-mutant Grade 3 oligodendroglioma who have received surgery as their only treatment. Part 3 will be an open-label single-arm cohort and will enroll participants concurrently with Part 2.