First Immunotherapy Receives FDA Approval for Esophageal Cancer Treatment

Pembrolizumab (Keytruda) immunotherapy significantly increased overall survival in patients whose PD-L1 positivity was %10 or higher in advanced esophageal (food pipe) cancer. These randomized phase III KEYNOTE-181 results were presented at the 2019 Gastrointestinal Cancers Symposium in San Francisco, United States, by Dr. Takashi Kojima of the National Cancer Center Hospital in Kashiwa, Japan.

Details and Results of KEYNOTE-181

• The study enrolled 628 patients with advanced esophageal cancer. Previously treated with at least 1 platinum-based chemotherapy line, they were randomized equally to two arms. One received pembrolizumab, an immune checkpoint inhibitor , at 200 mg every 3 weeks for up to 35 cycles. The chemotherapy arm received paclitaxel, docetaxel, or irinotecan at the investigator’s discretion.
• In 401 patients, the subtype was squamous cell carcinoma; the others had adenocarcinoma. In 222 patients, PD-L1 levels were %10 or higher.
• The primary endpoint was overall survival.
• Among patients with PD-L1 positivity of %10 or higher, median overall survival was 9.3 months with pembrolizumab and 6.7 months with chemotherapy. At month 12., overall survival rates were % 43 and % 20.
• Pembrolizumab recipients had fewer drug-related adverse effects than chemotherapy recipients.
• No significant survival difference was found in subgroups other than PD-L1-positive patients.

In conclusion , for second-line treatment of advanced esophageal cancer with PD-L1 positivity of %10 or higher, pembrolizumab significantly improved overall survival compared with chemotherapy.

For stage 4. esophageal cancer, another trial is evaluating pembrolizumab plus chemotherapy as first-line treatment (ClinicalTrials.gov code NCT02564263).