A Study of Pembrolizumab in Combination With Epacadostat in Women With Recurrent/Metastatic Endometrial Carcinoma

Primary Objective * Evaluate the response rate (RR) and 6 month progression-free survival (PFS-6) of patients with recurrent or metastatic endometrial carcinoma when treated with epacadostat in combination with pembrolizumab as measured by modified RECIST v1.1 * In a subset analysis, evaluate the response rate (RR) and 6 month progression-free survival (PFS-6) of patients with microsatellite instability (MSI) and recurrent or metastatic endometrial carcinoma when treated with epacadostat in combination with pembrolizumab. Secondary Objectives * Evaluate the safety and tolerability of epacadostat in combination with pembrolizumab. * Evaluate the overall survival (OS) of patients with recurrent or metastatic endometrial carcinoma when treated with epacadostat in combination with pembrolizumab as measured by modified RECIST v1.1. * In a subset analysis, evaluate the overall survival (OS) of patients with microsatellite instability (MSI) and recurrent or metastatic endometrial carcinoma when treated with epacadostat in combination with pembrolizumab.