This is a prospective, multicenter, double-blind, placebo-controlled, randomized Phase 3 study. The purpose of the study is to obtain evidence of efficacy for maintenance selinexor in participants with advanced or recurrent endometrial cancer. Participants with primary stage IV or recurrent disease who are in partial or complete response after having completed a single line of at least 12 weeks of taxane-platinum combo therapy will be randomized in a 2:1 manner to maintenance therapy with 80 milligram (mg) with selinexor once weekly (QW) or placebo until progression.