Clinical Trial of BMS-986504 in Recurrent GBM Patients

Inclusion Criteria: * Participants with the diagnosis of glioblastoma by the 2021 WHO criteria, who have progressed on or following previous tumor-directed therapy, which must have included a maximal safe resection (biopsy allowed if it was deemed unsafe to resect) and fractionated radiotherapy (RT). * Patients with archival tissue demonstrating MTAP loss/deletion confirmed through NGS will be qualified for Phase 0 portion of the study. * Participants must have measurable disease preoperatively, defined as at least 1 contrast-enhancing lesion, with 2 perpendicular measurements of at least 1 cm. * Participants who received chemotherapy must have recovered (Common Terminology Criteria for Adverse Events \[CTCAE\] Grade ≤ 1) from the acute effects of chemotherapy except for residual alopecia or Grade 2 peripheral neuropathy prior to Day 1. A washout period of at least 21 days is required between the last chemotherapy dose and Day 1 (provided the participant did not receive RT). * Age ≥ 18 at time of consent * Have a performance status (PS) of ≤ 2 on the Eastern Cooperative Oncology Group (ECOG) scale * Participant has adequate bone marrow and organ function as defined by the following laboratory values (as assessed by the local laboratory for eligibility): * Adequate Bone Marrow Function: Absolute neutrophil count ≥ 1,500/mcL; Platelets (at time of surgery) ≥ 100,000/mcL; Hemoglobin ≥ 9.0 g/dL (participants may receive erythrocyte transfusions to achieve this hemoglobin leve…