Years after Merck & Co.'s Keytruda failed to move the needle in newly diagnosed stomach cancer bearing the PD-L1 biomarker, the company has come back with a win, this time for tumors regardless of PD-L1 expression.
The company revealed positive results from a phase 3 trial assessing Keytruda combined with chemotherapy for newly diagnosed advanced HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma. The combo helped patients live longer than chemotherapy did on its own, Merck said. The Keytruda regimen achieved that in all patients regardless of their PD-L1 status.
The latest Keynote-859 trial win follows an approval last May for Keytruda, used alongside Roche's Herceptin, in HER2-positive stomach cancer. It also puts Keytruda on a collision course with Bristol Myers Squibb's Opdivo, which last April became the first PD-1/L1 inhibitor approved in frontline stomach cancer based on patient survival showing in HER2-negative patients.
Despite improvements in the field, advanced gastric cancer has one of the lowest five-year survival rates of all cancers, Dr. Eliav Barr, senior vice president and head of global clinical development and chief medical officer at Merck Research Laboratories, said in the company’s recent statement. The company is “excited” by the results, Barr added.
Stomach cancer is the fifth most diagnosed cancer and the fourth leading cause of cancer death worldwide, according to Merck. In 2020, nearly 1.1 million new cases were diagnosed, and the disease caused more than 768,000 deaths globally, with Asian populations disproportionally affected.
Keytruda once had a stomach cancer accelerated approval for third-line treatment. But after the confirmatory Keynote-062 trial failed to show a survival benefit for the Keytruda/chemo combo over chemo alone in frontline PD-L1-positive patients, Merck pulled the indication following a negative vote from the FDA’s oncology advisory committee.
Results of the new Keynote-859 study will be presented at an upcoming medical meeting and submitted to regulatory authorities. The drug, Merck’s crown jewel, raked in $42.65 billion from 2019 through 2021. In just the third quarter of this year, the blockbuster garnered $5.4 billion.