Merck is expanding the biomarker-driven use of its cancer immunotherapy drug with its latest approval from the Food and Drug Administration.
The Kenilworth, New Jersey-based company said Monday that the FDA had approved Keytruda (pembrolizumab), a PD-1 checkpoint inhibitor, as a first-line, single-agent therapy for patients with colorectal cancer that has spread or can’t be removed through surgery and that bears the microsatellite instability-high (MSI-H) or deficient mismatch repair (dMMR) biomarker.
When Merck received FDA approval for Keytruda for any solid tumor with MSI-H or dMMR that had progressed following prior treatment and had no treatment options in 2017, it marked the first the agency had granted a tumor-agnostic, biomarker-based label to a drug. Keytruda was also already approved for MSI-H or dMMR colorectal cancer that had progressed following treatment with certain chemotherapy drugs.
Keytruda’s closest competitor, Bristol-Myers Squibb PD-1 inhibitor Opdivo (nivolumab), is also approved as a single agent or combined with BMS’ Yervoy (ipilimumab) in previously treated MSI-H or dMMR colorectal cancer. But Merck said the new approval for Keytruda marks the first time a PD-1 inhibitor has been approved as a single-agent, first-line therapy in MSI-H or dMMR colorectal cancer.
The approval was based on results from the Phase III KEYNOTE-177 trial, which compared Keytruda against chemotherapy and showed a statistically significant 40% reduction in the risk of progression or death for patients receiving the PD-1 inhibitor, with a median progression-free survival of 16.5 months for Keytruda, versus 8.2 months for chemotherapy.
“Today’s approval has the potential to change the treatment paradigm for the first-line treatment of patients with MSI-H colorectal cancer, based on the important findings from KEYNOTE-177 that showed Keytruda monotherapy demonstrated superior progression-free survival compared to standard of care chemotherapy,” said Roy Baynes, chief medical officer of Merck Research Laboratories, in a statement. “Our commitment to pursuing biomarker research continues to help us bring new treatments to patients, particularly those who have few available options.”
The first drug to win a biomarker-based label as its sole indication was Vitrakvi (larotrectinib), for NTRK fusion-positive cancers, which was developed by Loxo Oncology and Bayer and which was taken over by the latter when Loxo was bought by Eli Lilly. Since then, Lilly’s Retevmo (selpercatinib), a RET inhibitor that Loxo had originally developed, has also won approval, but for a narrower indication.
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