Regulatory approval

Published by the Food and Drug Administration.

The U.S. Food and Drug Administration granted approval to pembrolizumab in combination with trastuzumab, fluoropyrimidine-, and platinum-containing chemotherapy for the first-line treatment of adult patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS >=1), as determined by an FDA-approved test. This indication is based on KEYNOTE-811 (NCT03615326), a multicenter, randomized, double-blind, placebo-controlled trial where patients received investigator's choice of chemotherapy between either cisplatin and 5-fu, or oxaliplatin and capecitabine.

This is written in the approval document as:

KEYTRUDA is a programmed death receptor-1 (PD-1)-blocking antibody indicated in combination with trastuzumab, fluoropyrimidine- and platinum-containing chemotherapy, for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma whose tumors express PD-L1 (CPS >=1) as determined by an FDA-approved test.

Citation

Merck Sharp & Dohme Corp. Keytruda (pembrolizumab) [package insert]. U.S. Food and Drug Administration website. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/125514s174lbl.pdf. Revised April 2025. Accessed April 30, 2025.

Therapeutic response

Precision oncology relationships for therapeutic response derived from this regulatory approval.

Type	Biomarker(s)	Cancer type	Therapy(ies)
Sensitivity (+)	HER2-positive, PD-L1 (CPS) >= 1	Adenocarcinoma of the Gastroesophageal Junction	Cisplatin, Fluorouracil, Pembrolizumab, Trastuzumab
Sensitivity (+)	HER2-positive, PD-L1 (CPS) >= 1	Adenocarcinoma of the Gastroesophageal Junction	Capecitabine, Oxaliplatin, Pembrolizumab, Trastuzumab