Merck’s Keytruda (pembrolizumab) has been found to reduce risk of death by 31% compared to chemotherapy, when used in previously treated patients with advanced esophageal or esophagogastric junction carcinoma, whose tumors expressed PD-L1.

The results from KEYNOTE-181, a Phase III trial investigating Merck’s Keytruda found that the drug met a primary endpoint by significantly improving overall survival (OS) in patients with squamous cell carcinoma or adenocarcinoma, who progressed after standard therapy and whose tumours expressed PD-L1.

The successful results showed a 31% reduction in the risk of death compared to chemotherapy, which is the first time an anti-PD-1 therapy has demonstrated a survival benefit for this patient population.

Among patients in the study whose tumours expressed PD-L1, the median overall survival in the Keytruda group was 9.3 months, compared to a median of 6.7 months for patients in the chemotherapy group.

"The prognosis for patients diagnosed with esophageal cancer is poor, and for those who experience disease progression, there is no established standard of care, underscoring the need for improved therapies in the second-line setting," said Dr. Takashi Kojima, professor at the Department of Gastroenterology and Gastrointestinal Oncology at the National Cancer Center Hospital East in Kashiwa, Japan.

He continued, ”The significant improvement in overall survival observed with Keytruda in patients with squamous cell carcinoma or adenocarcinoma whose tumors expressed PD-L1 with a CPS of 10 or greater represents an important scientific advancement and has the potential to benefit patients who currently have limited treatment options.”

The data from the KEYNOTE-181 study will be submitted to the US Food and Drug Administration (FDA) and other regulatory authorities for review.