2019 GI Cancers Symposium: Pembrolizumab in Second-Line Therapy for Advanced Esophageal Cancer
Pembrolizumab significantly improved overall survival in the second-line setting of advanced esophageal cancer in patients whose tumors tested positive for programmed cell death ligand 1 (PD-L1) with a combined positive score (CPS) of 10 or greater. This was compared to investigator’s choice of chemotherapy with docetaxel, paclitaxel, or irinotecan. These results from the randomized phase III KEYNOTE-181 study were presented earlier this week by Takashi Kojima, MD, of the National Cancer Center Hospital East in Kashiwa, Japan, at the 2019 Gastrointestinal Cancers Symposium in San Francisco (Abstract 2).
KEYNOTE-181 Details
In the study, the anti–programmed cell death receptor 1 agent pembrolizumab was compared to chemotherapy as second-line therapy for patients with advanced/metastatic squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus. The primary endpoint was overall survival in patients with SCC (n = 401), in patients whose tumors expressed PD-L1 with a CPS of 10 or greater (n = 222), and in all patients (n = 628).
Patients were randomly assigned by histology (SCC vs adenocarcinoma) and region (Asia vs elsewhere) to receive 200 mg of pembrolizumab every 3 weeks for up to 2 years or chemotherapy with docetaxel (75 mg/m2 on day 1 of each 21-day cycle), paclitaxel (80 to 100 mg/m2 on days 1, 8, and 15 of each 28-day cycle) or irinotecan (80 mg/m2 on day 1 of each 14-day cycle).
Study Findings
Overall survival was superior in patients receiving pembrolizumab whose tumors expressed PD-L1 with a CPS ≥ 10 at a median follow-up of 7.1 months, vs 6.9 months in the group receiving chemotherapy (9.3 vs 6.7 months, P = .0074). Overall survival at 12 months was 43% vs 20%, respectively. Patients receiving pembrolizumab experienced fewer drug-related adverse events vs patients receiving chemotherapy.
Statistical significance for improved overall survival with pembrolizumab vs chemotherapy was not met in the two other groups, including patients with SCC and all patients.
The investigators concluded that pembrolizumab significantly improved overall survival compared with chemotherapy as second-line therapy for patients with advanced esophageal cancer whose tumors expressed PD-L1 with a CPS of 10 or greater, with a more favorable safety profile. Dr. Kojima noted the findings represented an important scientific advance with the potential to benefit patients with advanced esophageal cancer that has progressed after first-line therapy.
A study is ongoing to evaluate pembrolizumab plus chemotherapy in the first-line treatment of patients with advanced esophageal cancer (ClinicalTrials.gov identifier NCT02564263).
Disclosure: The study authors' full disclosures can be found at coi.asco.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
