Recurrent MGMT-Methylated Glioblastoma

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 versus 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 deoxyribonucleic acid 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.