Merck & Co. Inc.'s blockbuster medicine Keytruda reduced the risk of death for patients with esophageal cancer by 31% when compared to chemotherapy during a phase 3 clinical trial.

The Kenilworth, N.J.-based company released topline results from the late-stage study called Keynote-181 in November 2018, which showed that the study met one of its main goals of improving overall survival in patients treated with Keytruda over chemotherapy. The detailed analysis of the reduced risk of death was issued by Merck in a Jan. 14 press release.

Cancer of the esophagus, which brings food from the mouth to the stomach, currently lacks a standard treatment protocol and can have a poor prognosis, according to Merck's press release. The reduction in the risk of death seen in patients treated with Keytruda was therefore encouraging, said Roy Baynes, senior vice president and head of global clinical development, as well as chief medical officer at Merck Research Laboratories.

Data from the trial will be submitted to the U.S. Food and Drug Administration for this indication.

Keytruda boosts the immune system's ability to kill cancer cells by blocking healthy cells' PD-1 protein from linking up with a partner arm on the surface of cancer cells known as the PD-L1 protein. The therapy is being studied in more than 850 trials for various types of cancers and treatment settings.