PRIMARY OBJECTIVE:~I. To evaluate the recommended phase 2 dose (RP2D) for mycophenolate mofetil (MMF) in combination with radiation therapy as well as in combination with temozolomide (TMZ).~SECONDARY OBJECTIVES:~I. To evaluate the safety profile of mycophenolate mofetil (MMF) in combination with temozolomide (TMZ).~II. To estimate progression free survival (PFS) per Response Assessment in Neuro-Oncology Criteria (RANO).~III. To estimate overall survival (OS). IV. To estimate the overall response rate (ORR) per RANO criteria. V. To evaluate quality of life per Functional Assessment of Cancer Therapy Scale-Brain (FACT-Br) for patients treated with mycophenolate mofetil and/or temozolomide.~EXPLORATORY OBJECTIVES:~I. To investigate the relationship between the molecular signature of individual glioblastoma multiforme (GBM) with clinical outcome, by measuring levels of serum mycophenolic acid in patient's plasma post MMF administration.~Ia. Perform molecular characterization of all GBM tissues by ribonucleic acid sequencing (RNAseq) analysis.~Ib. Perform bulk metabolomics for GBM tissue. Ic. Measure plasma and serum concentration of mycophenolic acid, the MMF's primary active metabolite, during and after combination therapy.~Id. Measure IMPDH activity assay in patients' peripheral blood mononuclear cells (PBMCs) as well as in GBM tissue.~OUTLINE: This is a dose-escalation study of MMF (Part 1), followed by a dose-expansion study (Part 2).~PART 1: Patients are assigned to 1 of 3 groups.~GROUP 1: Patients who have already undergone surgery or biopsy followed by chemoradiation receive TMZ orally (PO) once daily (QD) on days 1-5 of each cycle and MMF PO twice daily (BID). Treatment repeats every 28 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity.~GROUP 2: Patients with unmethylated glioblastoma who have already undergone surgery or biopsy receive TMZ PO QD on days 1-5 of each cycle and MMF PO BID. Treatment repeats every 28 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity. Starting at the same time as TMZ and MMF administration, patients also receive radiation therapy daily, 5 days per week, for 6 weeks.~GROUP S: Patients planning to undergo surgery receive MMF PO BID and TMZ PO QD for 5 days prior to surgery in the absence of disease progression or unacceptable toxicity.~PART 2: Patients are assigned to Group 3.~GROUP 3: Patients who have already undergone surgery or biopsy receive TMZ PO QD on days 1-5 of each cycle and MMF PO BID. Treatment repeats every 28 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity. Starting at the same time as TMZ and MMF administration, patients also receive radiation therapy daily, 5 days per week, for 6 weeks.~After completion of study treatment, patients are followed up at 30 days and then every 3 months for up to 18 months.
This phase I/Ib trial tests the safety, side effects, and best dose of mycophenolate mofetil in combination with temozolomide and/or radiation therapy (standard of care) in treating patients with glioblastoma. Mycophenolate mofetil is an immunosuppressant drug that is typically used to prevent organ rejection in transplant recipients. However, mycophenolate mofetil may also help chemotherapy with temozolomide work better by making tumor cells more sensitive to the drug. The purpose of this trial is to determine if mycophenolate mofetil combined with temozolomide can stop glioblastoma.