Study of Pembrolizumab (MK-3475) Versus Investigator's Choice Standard Therapy for Participants With Advanced Esophageal/ Esophagogastric Junction Carcinoma That Progressed After First-Line Therapy (MK-3475-181/KEYNOTE-181)

In this study, participants with advanced or metastatic adenocarcinoma or squamous cell carcinoma of the esophagus or Siewert type I adenocarcinoma of the esophagogastric junction (EGJ) that had progressed after first-line standard therapy were randomized to receive either pembrolizumab (MK-3475) OR the Investigator's choice of standard chemotherapy with paclitaxel, docetaxel, or irinotecan. The primary study hypothesis was that treatment with pembrolizumab would prolong overall survival (OS) as compared to treatment with standard chemotherapy.