Merck’s Keytruda fails to meet primary endpoint in gastric cancer trial

The phase 3 Keynote-061 trial assessing Keytruda as a second-line treatment for patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma did not achieve its primary endpoint of overall survival (OS) in patients whose tumors expressed PD-L1.

Keytruda is a humanized monoclonal antibody that can block the interaction between PD-1 and its ligands PD-L1 and PD-L2 to activate T lymphocytes, which may lead to the death of both tumor cells and healthy cells.

In September, Keytruda secured FDA approval as a third-line treatment for previously treated patients with recurrent locally advanced or metastatic gastric or gastroesophageal junction cancer whose tumors expressed PD-L1.

The company will continue to assess Keytruda for gastric or GEJ adenocarcinoma through Keynote-062 phase 3 clinical trial.

It will assess Keytruda as a monotherapy or in combination with chemotherapy as first-line treatment for patients with PD-L1 positive advanced gastric or gastroesophageal junction cancer.

Keynote-061 is a randomized, open-label and pivotal phase 3 trial designed to assess Keytruda as a monotherapy against paclitaxel in patients with advanced gastric or GEJ adenocarcinoma whose disease progressed after first-line treatment with platinum and fluoropyrimidine doublet therapy.

According to the company, the primary endpoints of the trial include PFS and OS in patients whose tumors express PD-L1, while secondary endpoints include PFS, OS and Overall Response Rate (ORR) in patients regardless of PD-L1 expression.

Merck Research Laboratories global clinical development head and chief medical officer Dr Roy Baynes said: “We remain committed to the continued study of Keytruda for gastric cancers and finding new options for patients facing this difficult-to-treat cancer type across various treatment settings.”