Merck announced that the European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) adopted a positive opinion recommending approval of KEYTRUDA, Merck’s anti-PD-1 therapy, in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of locally advanced unresectable or metastatic human epidermal growth factor receptor 2 (HER2)-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma in adults whose tumors express PD-L1 (Combined Positive Score [CPS] ≥1).

“This positive CHMP opinion reinforces our commitment to bringing meaningful treatment options to patients living with HER2-positive gastric or GEJ cancer, whose tumors express PD-L1 with a combined positive score ≥1, in the European Union,” said Dr. Scot Ebbinghaus, Vice President, Global Clinical Development, Merck Research Laboratories. “We look forward to the European Commission’s decision and are excited at the possibility of bringing the first approved immunotherapy regimen for the first-line treatment of these patients with HER2-positive advanced gastric or GEJ cancer to the EU.”

The recommendation is based on interim results from the Phase 3 KEYNOTE-811 trial, in which the KEYTRUDA regimen demonstrated a statistically significant improvement in progression-free survival (PFS) and objective response rate (ORR) compared to trastuzumab and chemotherapy alone in patients whose tumors expressed PD-L1 (CPS ≥1).

In the study, more than 80% of patients had tumors that were PD-L1 positive. These PFS results will be presented at an upcoming medical meeting. The CHMP’s recommendation will now be reviewed by the European Commission for marketing authorization in the European Union, and a final decision is expected in the third quarter of 2023.