Inclusion Criteria:

1. Age ≥18 years at the time of signing the informed consent form (ICF).
2. New Diagnosed with histologically or molecularly confirmed IDH wild type and MGMT unmethylated GBM.
3. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) 0, 1 or 2.
4. The following laboratory values obtained ≤15 days prior to registration:

1. Hemoglobin ≥9.0 g/dL
2. Absolute neutrophil count (ANC) ≥1500/mm3
3. Platelet count ≥100,000/mm3
4. Total bilirubin ≤1.5 x upper limit of normal (ULN)
5. Alanine aminotransferase (ALT) and aspartate transaminase (AST) ≤3 x ULN (or ≤5 x ULN for participants with liver involvement)
6. Prothrombin time (PT)/ International normalized ratio (INR)/ Activated partial thromboplastin time (aPTT) ≤1.5 x ULN OR if participant is receiving anticoagulant therapy and INR or aPTT is within target range of therapy
7. Serum eGFR ≥60 ml/min
5. QTc 470 ms on triplicate 12 lead ECG ≤29 days prior to registration. NOTE: QTc intervals will be corrected using Fridericia's formula (Fridericia 1920)
6. Echocardiographic Assessment: Left Ventricular Ejection Fraction (LVEF) ≥ 55%.
7. Negative serum pregnancy test done ≤7 days prior to first dose of MT-125 administration, for persons of childbearing potential only.

a. If \>7 days between last test and first dose of study treatment, the serum pregnancy test will be repeated.
8. Has provided written informed consent.
9. Ability to complete questionnaire(s) by themselves or with assistance.
10. Willing to return to enrolling institution for follow-up (during the Active Monitoring Phase of the study).
11. On a stable dose of steroids for at least 2 weeks prior to enrollment

Exclusion Criteria:

1. Any of the following because this study involves an investigational agent, the genotoxic, mutagenic, and teratogenic effects of which on the developing fetus and newborn are unknown:

1. Pregnant persons
2. Nursing persons
3. Persons of childbearing potential and persons able to father a child who are unwilling to employ adequate contraception.
2. Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the participant inappropriate for entry into this study or interfere significantly with the proper assessment of safety and toxicity of the prescribed regimens.
3. Receiving any other investigational agent.
4. Any concomitant disease, condition, or treatment that could interfere with the conduct of the study, or that would, in the opinion of the Investigator or Sponsor, pose an unacceptable risk to the participant in the study or interfere with the interpretation of study data.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 10/01/2025. Questions regarding updates should be directed to the study team contact.