SIGMA (Safusidenib in IDH1 Mutant Glioma Maintenance)

Part 1 of this study will enroll up to 25 patients that will be randomized 1:1:1:1:1 (5 patients per group) to receive one of the daily oral doses of safusidenib at 125 mg twice a day (BID), 250 mg BID, 500 mg once daily (QD), 375 mg BID, or 500 mg BID. The PK characteristics and safety and initial efficacy data will be assessed in Part 1. Part 1 was fully enrolled as of 19 Dec 2023 and participants are currently ongoing. Part 2 will include approximately 300 participants with 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. Participants will be randomized (1:1) after their last dose of adjuvant temozolomide to receive either oral safusidenib 250 mg BID or placebo in 28-day continuous cycles. Patients will continue treatment until progression of disease or until other discontinuation criteria are met. The tumor response evaluation will be conducted on a regular basis until progression of disease per Blinded Independent Central Review (BICR), consent withdrawal, or death, whichever occurs first. Long-term survival follow-up will be conducted as well. Part 3 will include approximately 40 participants with residual or recurrent IDH1-mutant Grade 3 oligodendroglioma with measurable disease who have undergone surgery as their only treatment and are not in need of immediate chemotherapy or radiotherapy. Participants will receive oral safusidenib 250 mg BID in 28-day continuous cycles until disease progression or another reason for discontinuation occurs.