Additional Study Information: The purpose of the research study is to see if selinexor has any effects against your cancer and toevaluate the side-effects of selinexor or selinexor in combination with temozolomide (TMZ ). One specific way cancer cells continue to grow is by getting rid of certain proteins called tumor suppressor proteins that would normally cause cancer cells to die. This study drug, Selinexor, works by keeping tumor suppressing proteins within the nucleus of the cell, thus causing the cancer cells to die or stop growing.