Phase 0 With Expansion Phase Clinical Trial of Quisinostat Plus Radiotherapy in Newly-diagnosed and Recurrent Grade 4 IDH-Wildtype Glioblastomas

Inclusion Criteria: * For Arm A: Participants who have had a prior resection of diagnosed glioblastoma, IDH wildtype (2021 WHO grade 4), defined as participants who have progressed on or following standard therapy, which includes maximal surgical resection, temozolomide, and fractionated radiotherapy. Participants will also need to have radiation planned as part of the post-surgical treatment plan; OR, for Arm B only: Participants undergoing resection for a suspected newly diagnosed WHO Grade 4 glioblastoma, IDH wildtype. Participants will also need to have radiation planned as part of the post-surgical treatment plan. * Participants must have measurable disease preoperatively, defined as at least 1 contrast-enhancing lesion, with 2 perpendicular measurements of at least 1 cm. * Provision of signed and dated, written informed consent (personally or by the legally authorized representative, if applicable) prior to any study specific procedures, sampling and analyses. * Age ≥18 at time of consent * Have a performance status (PS) of ≤2 on the Eastern Cooperative Oncology Group (ECOG) scale. * Ability to swallow oral medications. * Participant has adequate bone marrow and organ function as defined by the following laboratory values (as assessed by the local laboratory for eligibility): * Participants with tumor-induced seizures must be well-controlled on a stable anti-epileptic treatment. * Participants must be willing to receive prophylaxis with levetiracetam for the duration o…