Primary Objectives: To assess the antitumor activity (proportion of objective response by
RECIST 1.1 criteria) of pembrolizumab with objective tumor response in patients with
persistent, recurrent or metastatic endometrial cancer harboring an ultra-mutated or
hyper-mutated (MMR gene-defective) phenotype identified by next generation sequencing (NGS)
and comprehensive genomic profiling (CGP). To determine the nature and degree of toxicity of
pembrolizumab as assessed by CTCAE in patients with persistent, recurrent or metastatic
endometrial carcinoma. Secondary Objective(s): To estimate the duration of progression-free
survival (PFS) and overall survival (OS).