Keytruda gets front-line gastric cancer okay in EU

US Merck & Co

The European Commission has given approval to MSD's Keytruda as a first-line therapy for advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma.

PD-1 inhibitor Keytruda (pembrolizumab) has been cleared in combination with trastuzumab, fluoropyrimidine, and platinum-containing chemotherapy for gastric and HEJ tumours that are HER2-positive and also express PD-L1, becoming the first immunotherapy option for these patients in the EU, according to the company.

The go-ahead comes on the back of the KEYNOTE-811 study, in which the Keytruda regimen achieved an overall response rate (ORR) of 74%, including 11% complete responses, with a median duration of response of 10.6 months, compared to placebo.

There was also a statistically significant improvement in progression-free survival (PFS) compared to placebo in combination with trastuzumab and chemotherapy in the intention-to-treat (ITT) study population, but only in PD-L1-positive cancers, as well as a trend towards improved overall survival.

Keytruda has been given accelerated approval in the US for first-line use in HER2-positive gastric or GEJ adenocarcinoma since May 2021, but MSD – known as Merck & Co in the US – applied a few weeks ago to update the label with the new PFS data and convert it to a full license. In the KEYNOTE-811 study, more than 80% of patients were in the PD-L1 positive category.

"Patients in the EU diagnosed with HER2-positive advanced gastric cancer face an aggressive disease associated with a poor prognosis, underscoring the need for additional first-line treatment options for these patients," said Dr Scot Ebbinghaus, head of global clinical development at Merck Research Laboratories.

"With today's approval of Keytruda, we're proud that patients whose tumours express PD-L1 with a combined positive score ≥1 and healthcare providers in the EU will have an option that includes immunotherapy for this difficult-to-treat disease."

Bristol-Myers Squibb also has approval in the US and EU for Opdivo (nivolumab) in combination with chemo as a first-line therapy for advanced gastric, GEJ, and oesophageal adenocarcinoma, based on the CheckMate-649 study, but only in HER2-negative, PD-L1-positive patients.

Keytruda was previously also approved in the US for PD-L1–positive gastric or GEJ adenocarcinoma in patients who have received two or more earlier lines of therapy, but that indication was withdrawn after the drug failed to show an improvement in two confirmatory studies.