FDA grants traditional appro for Keytruda in GEJ

The US Food and Drug Administration (FDA) has granted traditional approval to Merck & Co’s (NYSE: MRK) Keytruda (pembrolizumab) 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).

PD-1 inhibitor pembrolizumab previously received accelerated approval for this indication on May 5, 2021, based on interim analysis of the trial data. Keytruda, authorized in a range of indications, is the US pharma giant’s by far the best-selling product, generating revenues of $29,48 billon in 2024, up 18%, for Merck, and making it the top selling drug globally.

The FDA noted that efficacy was evaluated in KEYNOTE-811 (NCT03615326), a multicenter, randomized, double-blind, placebo-controlled trial enrolling 698 patients with HER2-positive advanced gastric or GEJ adenocarcinoma not previously treated with systemic therapy for metastatic disease. Among the 698 patients, 594 (85%) had tumors expressing PD-L1 with a CPS ≥1 using the PD-L1 IHC 22C3 pharmDx kit. Patients were randomized (1:1) to pembrolizumab 200 mg or placebo, in combination with trastuzumab and either fluorouracil plus cisplatin or capecitabine plus oxaliplatin.