Newly-Diagnosed Inclusion Criteria:

• Age ≥ 18 years.
• Histologically confirmed Grade IV GBM/gliosarcoma established following either a surgical resection or biopsy.
• Karnofsky performance status ≥ 60% performed within a 14-day window prior to randomization.
• Availability of tumor tissue representative of GBM from definitive surgery or biopsy.

Recurrent Inclusion Criteria:

• Age ≥ 18 years.
• Histologically confirmed GBM/gliosarcoma (WHO criteria; non-IDH R132H mutant) at first or second recurrence after initial standard, control or experimental therapy that includes at a minimum Radiation Therapy (RT).
• Evidence of recurrent disease (RD) demonstrated by disease progression using slightly modified Response Assessment in Neuro-Oncology (RANO) criteria.
• Karnofsky performance status ≥ 70% performed within a 14-day window prior to randomization.
• Availability of tumor tissue representative of GBM from initial definitive surgery and/or, recurrent surgery, if performed.

Newly-Diagnosed Exclusion Criteria:

• Any prior treatment for glioma including: prior prolifeprospan 20 with carmustine wafer; prior intracerebral agent; prior radiation treatment for GBM or lower-grade glioma; prior chemotherapy or immunotherapy for GBM or lower-grade glioma.
• Receiving additional, concurrent, active therapy for GBM outside of the trial.
• Extensive leptomeningeal disease.
• QTc > 450 msec if male and QTc > 470 msec if female.
• History of another malignancy in the previous 3 years, with a disease-free interval of < 3 years. Patients with prior history of in situ cancer or basal or squamous cell skin cancer are eligible.

Recurrent Exclusion Criteria:

• Early disease progression prior to 3 months (12 weeks) from the completion of RT.
• More than 2 prior lines for chemotherapy administration.
  • NOTE: In the 1st line adjuvant setting, combination of Temozolomide (TMZ) with an experimental agent, is considered one line of chemotherapy.
• Any prior treatment with bevacizumab or other VEG)- or VEGF receptor-mediated targeted agent.
• Any prior treatment with prolifeprospan 20 with carmustine wafer.
• Any prior treatment with an intracerebral agent.
• Receiving additional, concurrent, active therapy for GBM outside of the trial.
• Extensive leptomeningeal disease.
• QTc > 450 msec if male and QTc > 470 msec if female.
• History of another malignancy in the previous 2 years, with a disease-free interval of < 2 years. Participant with prior history of in situ cancer or basal or squamous cell skin cancer are eligible.