Efficacy and Safety of a Repurposed Drug Added to the Combination of Len Plus Pem in Advanced Endometrial Cancer

This is a Phase 3, multicenter, randomized, open-label trial to evaluate whether EG-007 plus Len+Pem is superior to Len+Pem alone in patients with advanced endometrial cancer (Stage III or IV). This trial will be preceded by a safety lead-in study with up to 28 patients (the safety lead-in is a separate, free-standing protocol). Approximately 450 patients will be randomized equally (1:1) to receive EG-007 plus Len+Pem or Len+Pem alone. The randomization will be stratified by the following stratification factors: * Diagnosis Classification (advanced Stage III/IV vs. recurrent endometrial cancer) * ECOG score at baseline (0 vs 1) * Geographic region (Asia vs ROW)