Pembrolizumab (MK-3475) Plus Lenvatinib (E7080/MK-7902) Versus Chemotherapy for Endometrial Carcinoma (ENGOT-en9 / MK-7902-001)

Inclusion Criteria: * Has Stage III, Stage IV, or recurrent, histologically-confirmed endometrial carcinoma with disease that is either measurable or nonmeasurable but radiographically apparent, per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1) as assessed by blinded independent central review (BICR) (note: may have received prior chemotherapy only if administered concurrently with radiation; may have received prior radiation without concurrent chemotherapy; may have received prior hormonal therapy for treatment of endometrial carcinoma, provided that it was discontinued ≥1 week prior to randomization; and may have received 1 prior line of systemic platinum-based adjuvant and/or neoadjuvant chemotherapy) * Has provided archival tumor tissue sample or newly obtained core or excisional biopsy of a tumor lesion that was not previously irradiated, for determination of mismatch repair (MMR) status * Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, as assessed within 7 days prior to the first dose of study intervention * Is not pregnant or breastfeeding, and is either not a woman of childbearing potential (WOCBP) or is a WOCBP who agrees to use contraception during the study and for ≥120 days after pembrolizumab, ≥30 days after lenvatinib, or ≥180 days after (chemotherapy) \[if a WOCBP, a pregnancy test will be required within 24 hours of first dose of study drug\] * Has adequately controlled blood pressure within 7 days prior …