Testing the Addition of an Anti-cancer Drug, Selinexor, to the Usual Chemotherapy Treatment (Temozolomide) for Brain Tumors That Have Returned After Previous Treatment

This phase I/II trial tests the safety, side effects and best dose of selinexor given in combination with the usual chemotherapy (temozolomide) and compares the effect of this combination therapy vs. the usual chemotherapy alone (temozolomide) in treating patients with glioblastoma that has come back (recurrent). Selinexor is in a class of medications called selective inhibitors of nuclear export (SINE). It works by blocking a protein called CRM1, which may keep cancer cells from growing and may kill them. Temozolomide is in a class of medications called alkylating agents. It works by damaging the cell's DNA and may kill tumor cells and slow down or stop tumor growth. Giving selinexor in combination with usual chemotherapy (temozolomide) may shrink or stabilize the tumor better than the usual chemotherapy with temozolomide alone in patients with recurrent glioblastoma.

PRIMARY OBJECTIVES: I. To determine the maximum tolerated dose of temozolomide followed by selinexor in recurrent glioblastoma patients as determined by dose-limiting toxicities (DLTs) and the total toxicity profile. (Phase I) II. To evaluate the efficacy of sequentially administering temozolomide and selinexor in recurrent glioblastoma as determined by progression-free survival (PFS). (Phase 2) SECONDARY OBJECTIVES: I. To evaluate overall response rate as determined by Response Assessment in Neuro-Oncology (RANO) response criteria. II. To evaluate the efficacy of sequentially administering temozolomide and selinexor in recurrent glioblastoma as determined by 6-month PFS (6mPFS) and overall survival (OS). III. To validate signatures of vulnerability to predict response to selinexor through ribonucleic acid (RNA) sequencing for 6 top-scoring gene pairs, whole exome sequencing, P53, EGFR, and Mcl-1. OUTLINE: This is a phase I, dose-escalation study of selinexor in combination with fixed dose temozolomide followed by a phase II study that compares selinexor temozolomide combination therapy vs. temozolomide monotherapy. Patients are randomized to 1 of 2 groups for the phase II part of this trial. GROUP I (Phase II): Patients receive temozolomide orally (PO) on days 1-5 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. GROUP II (Phase I and II): Patients receive temozolomide PO on days 1-5 of each cycle and selinexor PO on days 8 and 15 of each cycle. Cycles repeat every 28 days in the absence of disease progression or unacceptable toxicity. (Phase I completed as of April 2024) Patients undergo magnetic resonance imaging (MRI) throughout the study and blood sample collection while on study. After completion of study treatment, patients are followed up every 2 months up to 2 years.