Merck's Keytruda aims for updated stomach cancer label with positive data

Merck’s cancer star Keytruda could be on its way to an updated label in HER2-positive stomach cancer after showing it can stave off tumor progression in a combination study.

Keytruda scored its original gastric cancer approval in 2021 under the FDA's accelerated approval program based on tumor shrinkage data. Its continued approval hinges on positive confirmatory data. Now, the company is working with the FDA to update the current indication to include disease progression data in patients whose tumors express PD-L1, the company said in its Friday release.

It’s not immediately clear whether Merck intends to convince the FDA to convert the approval into a full one. Bristol Myers Squibb's Opdivo scored the PD-1 inhibitor class’s first nod in stomach cancer based on data showing it could save lives.

Keytruda’s new results come from a 732-patient trial in locally advanced unresectable or metastatic HER2-positive gastric or GEJ (gastroesophageal junction) adenocarcinoma. Keytruda, used along with Roche’s Herceptin and chemotherapy, showed an improvement in progression-free survival compared with the Herceptin-chemo combo, but only in patients with PD-L1 positive tumors. The group made up more than 80% of the trial.

A “trend toward improvement” in overall survival was seen in the study, but it didn’t reach statistical significance. That endpoint will now be tested at “subsequent analysis,” according to Merck.

“These new data from KEYNOTE-811, demonstrating a significant improvement in progression-free survival, are meaningful and build on the earlier insights from this study that supported the accelerated approval of this Keytruda combination in the U.S. for certain patients with HER2-positive gastric or GEJ adenocarcinoma,” Merck Research Laboratories' vice president of global clinical development, Dr. Scot Ebbinghaus, said in a statement.

Stomach cancer is the fourth leading cause of cancer deaths worldwide with only a 6% five-year survival rate at advanced stages. More than 70% of patients with the cancer type develop advanced-stage disease, Merck said.

The recent trial is just one of the 1,600 Keytruda trials ongoing across a range of cancer types and treatment settings. The drug pulled in $20.9 billion in sales last year.