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.

Who can Participate

Detailed eligibility criteria is available on clinicaltrials.gov. These requirements will be discussed with your doctor and/or study representative. Click the NCT number link below to learn more about this study on ClinicalTrials.gov Key Inclusion Criteria for Part 2 and 3: Must be >= 18 years old at the time of signing the ICF. Must agree to submit sufficient tumor tissue for retrospective biomarker and histological analyses. This requirement may be waived in rare circumstances with approval by the Sponsor. Has adequate hematologic and organ function Key Inclusion Criteria for Part 2: Diagnosis of histologically confirmed IDH1-mutant Grade 2, Grade 3 with high risk features or Grade 4 astrocytoma, per WHO 2021 classification and Investigator Assessment. Have an IDH1 mutation (R132H/C/G/S/L) based on IHC (R132H only), polymerase chain reaction (PCR), or next-generation sequencing (NGS). CDKN2A/B status and at least 1 of the following must be confirmed: absence of 1p19q co-deletion by fluorescence in situ hybridization, array comparative genomic hybridization, or NGS; presence of an ATRX loss of function mutation by NGS; or loss of normal ATRX expression by IHC. A validated assay performed in a CLIA-certified/CAP-accredited (or local equivalent) clinical laboratory must be used for all of the aforementioned results. Documentation of biomarker status, including redacted molecular pathology and NGS reports, must be provided during Screening. Must not have experienced tumor recurrence or progression between first day of radiotherapy and randomization by local assessment per RANO 2.0. Participants must have completed radiation therapy with a minimum of 80% of planned treatment completed (with or without concurrent temozolomide) and between 6 and 12 cycles of adjuvant . Randomization must occur at least 28 days and not more than 75 days after the final dose of temozolomide. Key Inclusion Criteria for Part 3: Have had at least 1 prior surgery for glioma (biopsy, sub-total resection, or gross total resection), with the most recent surgery having occurred at least 90 days and no longer than 5 years before the date of enrollment, have not had any other prior anticancer therapy, including chemotherapy and radiotherapy, and are not in need of immediate chemotherapy or radiotherapy in the opinion of the Investigator. Have histologically confirmed Grade 3 IDH-mutant oligodendroglioma according to WHO 2021 criteria per local assessment. Have residual or recurrent measurable disease per RANO 2.0 and confirmed by BICR, at the time of enrollment. Have an IDH1 mutation (R132H/C/G/S/L). The presence of 1p19q co-deletion must also be confirmed. All results must be generated using a validated assay performed in a CLIA-certified/CAP-accredited (or local equivalent) clinical laboratory.

Study ID

More information available at ClinicalTrials.gov: NCT05303519