MSD’s Keytruda has shown promise in a late-stage trial testing its safety and efficacy in patients with advanced or metastatic esophageal or esophagogastric junction carcinoma.

The Phase III KEYNOTE-181 trial, which investigated the drug as monotherapy in the second-line setting, met a primary endpoint of overall survival (OS) in patients whose tumors expressed PD-L1 (Combined Positive Score [CPS] ≥10).

Treatment with Keytruda (pembrolizumab) resulted in a statistically significant improvement in overall survival compared to chemotherapy (paclitaxel, docetaxel or irinotecan) in patients with CPS ≥10, regardless of histology.

The primary endpoint of OS was also evaluated in patients with squamous cell histology and in the entire intention-to-treat (ITT) study population, but this failed to reach statistical significance.

"This marks the sixth tumor type where Keytruda has demonstrated a survival benefit, and represents the first time an anti-PD-1 therapy has achieved overall survival for this patient population," noted Dr Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories.

"We are encouraged by these results of Keytruda as monotherapy in previously-treated patients, and look forward to continuing our research efforts in this significant area of unmet need with our ongoing Phase III trial, KEYNOTE-590, evaluating Keytruda in combination with chemotherapy as a first-line treatment for patients with esophageal carcinoma."