Merck’s Keytruda Approved in Combination with Trastuzumab and Chemotherapy for Cancer Treatment

Merck, known as MSD outside of the United States and Canada, announced on May 5, 2021 that FDA has approved Keytruda (pembrolizumab), Merck’s anti-PD-1 therapy, in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the treatment of patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma.

The approval was based on positive data from the ongoing Phase III KEYNOTE-811 trial, where patients who received trastuzumab with Keytruda had a complete response rate of 11% and a partial response rate of 63%, while patients who received trastuzumab and chemotherapy alone had a complete response rate of 3.1% and a partial response rate of 49%, Merck said in a company press release.

“Today’s approval marks an important milestone, as this is the first time an anti-PD-1 therapy has been approved in combination with anti-HER2 therapy and chemotherapy as a first-line treatment for these patients,” said Dr. Roy Baynes, senior vice-president and head of global clinical development, chief medical officer, Merck Research Laboratories, in the press release. “From the start of Keytruda’s development, we have thoughtfully pursued novel combinations to help more patients with cancer. We are pleased to bring a new first-line combination regimen with Keytruda that has shown meaningful improvement in ORR (objective response rate) over standard treatment to patients with HER2-positive gastric and GEJ cancer.”