Selinexor in Treating Younger Patients With Recurrent or Refractory Solid Tumors or High-Grade Gliomas

This phase I trial studies the side effects and best dose of selinexor in treating younger patients with solid tumors or central nervous system (CNS) tumors that have come back (recurrent) or do not respond to treatment (refractory). Drugs used in chemotherapy, such as selinexor, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading.