• Histologically confirmed World Health Organization (WHO) 2021 defined glioblastoma. A pathology report constitutes adequate documentation of histology for study inclusion.

• Radiographic demonstration of disease progression following prior therapy.

• Patients having undergone recent resection of recurrent or progressive tumor will be eligible as long as the patient has recovered from surgery. Evaluable or measurable disease following resection of recurrent tumor is not mandated for eligibility into the study.

• Prior standard radiation for glioblastoma (short course 40 Gy, standard 60 Gy, and proton therapy are allowed).

• Patients must have recovered from the effects of prior therapy.

• The following listed agents/interventions must have been discontinued for their respective time period prior to enrollment:

∙ Four weeks from cytotoxic agents (3 weeks from procarbazine, 3 weeks from vincristine, and 4 weeks from temozolomide);

‣ Four weeks or 5 drug half-lives (whichever is shorter) from any investigational agent; two weeks or 5 drug half-lives (whichever is shorter) from non-cytotoxic agents (e.g. Accutane, thalidomide);

‣ Twelve weeks from radiotherapy to minimize the potential for MRI changes related to radiation necrosis that might be misdiagnosed as progressive disease, or 4 weeks if a new lesion, relative to the pre-radiation MRI, develops that is outside the primary radiation field;

• Patients must have the following laboratory parameters ≤ 14 days prior to registration:

• a. adequate bone marrow function defined by: i. white blood cells (WBC) ≥ 3 × 109/L , ii. absolute neutrophil count (ANC) ≥ 1.5 × 109/L , iii. platelet count of ≥ 100 × 109/L , and iv. hemoglobin ≥ 9 gm/dL b. adequate liver function defined by i. alanine transaminase (ALT, SGPT) and aspartate transaminase (AST/SGOT) \< 3× institutional upper limit of normal (ULN), ii. alkaline phosphatase \< 2× ULN, and iii. bilirubin \< 1.5 mg/dL c. adequate renal function defined by calculated creatinine clearance ≥ 60 mL/min (see Appendix)

• Karnofsky performance status (KPS) ≥ 50 (see Appendix).

• Individuals of childbearing potential or those with partners of childbearing potential must agree to use adequate methods of contraception for the duration of study participation (including dosing interruptions) and for up to 3.5 months after the last study treatment; or be surgically sterilized.

⁃ Patients on the following medications are allowed:

• Anticoagulants: Patients on stable dose anticoagulants (e.g. warfarin in-range international normalized ratio \[INR\], low molecular-weight heparin)

∙ Patients are allowed to take aspirin, clopidogrel, ticlopidine, Aggrenox, ibuprofen and other NSAIDS.

⁃ Patients must be willing to forego other cytotoxic and non-cytotoxic drug therapy for glioblastoma while enrolled in the study.

⁃ Able to swallow oral medication.

⁃ Patients ≥18 years of age at time of consent.

⁃ Ability to understand and willingness to sign an informed consent form (ICF).

⁃ Ability and stated willingness to adhere to the study visit schedule and protocol procedures/requirements, including periodic blood sampling and study related assessments