A Study Comparing Niraparib With Temozolomide in Adult Participants With Newly-diagnosed, MGMT Unmethylated Glioblastoma

Inclusion Criteria: * 1\. Histologic documentation of a newly-diagnosed intracranial GBM, per 2021 WHO classification guidelines through local pathology review. * 2\. Age ≥18 years at the time of signing informed consent. * 3\. Sufficient tissue available for retrospective central pathology review, retrospective central confirmation of MGMT promoter methylation status and genomic analysis. If insufficient tissue is available,pproval may be granted on a case-by-case basis after a review. * 4\. Unmethylated MGMT promoter region determined locally by a validated PSQ or qMS-PCR assay compliant to local regulations. Numerical cut-off for an MGMT unmethylated tumor will be defined in the protocol. * 5\. Suitability for SOC RT to 60 Gy in 30 fractions using ESTRO-EANO 'single phase' targeting approach \[Niyazi, 2023\], per investigator's judgment. * 6\. No prior treatment for GBM (including brachytherapy or BCNU wafers), other than surgical resection or biopsy. * 7\. Female participants: Not pregnant, planning to get pregnant, or breastfeeding and one of the following conditions apply: is of nonchildbearing potential or is of childbearing potential AND using a contraceptive method that is highly effective (with a failure rate of \<1% per year) from screening through at least 180 days after the last dose of study intervention. Breastfeeding is contraindicated during the study and for one month after the last dose of study intervention. * 8\. Male participants: Must agree to the foll…