Pembrolizumab versus chemotherapy as second-line therapy for advanced esophageal cancer: Phase III KEYNOTE-181 study.

2Background: Patients with advanced esophageal cancer after first-line chemotherapy (chemo) have a poor prognosis and limited treatment options. We present results of the phase 3 KEYNOTE-181 study of pembrolizumab vs investigator’s choice chemo as second-line therapy for patients (pts) with advanced/metastatic squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus or Siewert type I adenocarcinoma of the EGJ (NCT02564263). Methods: Eligible pts were randomized 1:1 to pembrolizumab 200 mg Q3W for up to 2 years or investigator’s choice chemo of paclitaxel, docetaxel, or irinotecan. Randomization was stratified by histology (SCC vs adenocarcinoma) and region (Asia vs rest of world). Primary end points were OS in the SCC, PD-L1 combined positive score (CPS) ≥10, and ITT populations. Results: 628 pts were randomized including 401 with SCC, and 222 with CPS ≥10. As of October 15, 2018, the median follow-up was 7.1 mo (pembrolizumab) vs 6.9 mo (chemo). Pembrolizumab was superior to chemo for OS in CPS ...