MSD has announced that its anti-PD-1 therapy Keytruda (pembrolizumab) did not meet its co-primary endpoints in the Phase III KEYNOTE-240 trial.

The therapy, plus best supportive care, did not meet its co-primary endpoints of overall survival (OS) and progression-free survival (PFS) versus placebo with best supportive care in patients with advanced hepatocellular carcinoma (HCC) who were previously treated with systemic therapy.

The results for the endpoints were, however, "generally consistent" with findings from the Phase II KEYNOTE-224 study, which led to an accelerated US Food and Drug Administration (FDA) approval of Keytruda last November for the treatment of patients with HCC previously treated with Bayer's Nexavar (sorafenib).

“While we are disappointed KEYNOTE-240 did not meet its co-primary endpoints, the results for overall survival, progression-free survival and objective response rate are generally consistent with findings from the Phase 2 study, KEYNOTE-224, which led to the accelerated approval of Keytruda for the treatment of patients with hepatocellular carcinoma who have been previously treated with sorafenib,” said Dr Roy Baynes, senior vice president and head of global clinical development, chief medical officer, Merck Research Laboratories.

He continued, “We sincerely thank the patients and investigators for their participation in this study and are committed to helping patients diagnosed with this common and difficult-to-treat type of liver cancer.”

In the final analysis of the study, there was an improvement in OS for patients treated compared to placebo, however these results did not meet statistical significance per the pre-specified statistical plan, and results will be presented at an upcoming medical meeting and have been shared with the FDA for discussion.