Efficacy and Safety of Pembrolizumab (MK-3475) Plus Lenvatinib (E7080/MK-7902) Plus Chemotherapy in Participants With Metastatic Esophageal Carcinoma (MK-7902-014/E7080-G000-320/LEAP-014)

The purpose of this study is to assess the efficacy and safety of pembrolizumab plus lenvatinib plus chemotherapy compared with pembrolizumab plus chemotherapy as first-line intervention in participants with metastatic esophageal carcinoma. The primary hypotheses are that pembrolizumab plus lenvatinib plus chemotherapy is superior to pembrolizumab plus chemotherapy with respect to overall survival (OS) per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) by blinded independent central review (BICR). As of Amendment 09, Study MK-7902-014 will begin close out activities. Any participant who discontinues study intervention for any reason will be discontinued from the study without further follow-up. Second Course and treatment beyond disease progression will no longer be offered. No safety concerns contributed to the termination of this study.

There will be 2 parts to the study: the cisplatin and 5-fluorouracil (5-FU) (FP) and paclitaxel and cisplatin (TP) Safety Run-in (Part 1) and the Main Study (Part 2). In Part 1 (FP and TP Safety Run-in), participants will be treated with pembrolizumab plus lenvatinib plus FP or TP. Dose-limiting toxicities, safety, and tolerability will be assessed. In Part 2 (Main Study), participants (not including those participating in Part 1) will be treated with pembrolizumab plus lenvatinib plus chemotherapy or pembrolizumab plus chemotherapy. Efficacy, safety, and tolerability will be assessed.