Dive Brief:

• Merck & Co. has begun a large clinical trial testing an experimental cancer drug it’s developing for tumors that harbor mutations in a tough-to-target gene called KRAS,
• The Phase 3 study, which is set to enroll some 600 people with a common form of metastatic lung cancer, will pit the KRAS inhibitor together with Merck’s immunotherapy Keytruda against Keytruda alone. Researchers will assess whether the combination slows tumor progression and helps people live longer.
• Dubbed MK-1084, the experimental KRAS inhibitor is currently in Phase 1 testing. Based on early results, Merck thinks the drug could work well together with Keytruda to treat certain people with KRAS-mutated lung tumors.

Dive Insight:

First Amgen and then Mirati Therapeutics won U.S. approvals for KRAS cancer medicines, dispelling the gene’s long-held reputation as “undruggable.”

While sales have been slower than analysts expected, and Amgen has run into confirmatory testing difficulties, the drugs are viewed as building blocks for curbing tumors that resist other treatment. Both Amgen and Bristol Myers Squibb, which bought Mirati last fall, are testing their respective drugs alongside other therapies, as well as in earlier settings.

Merck aims to compete as well and its trial could provide evidence for using MK-1084 alongside Keytruda, which is the dominant immunotherapy for lung cancer treatment. Enrollment is limited to patients who both have confirmed KRAS mutations as well as high levels of a protein that’s associated with response to immunotherapy. The study is set to reach primary completion by 2029, although interim results could come sooner.

Merck got access to MK-1084 through a 2020 alliance with Taiho Pharmaceutical Co. and Astex Pharmaceuticals.

Amgen and Bristol Myers are also studying their respective KRAS drugs in combination with immunotherapies, including Keytruda.

Sales of Amgen’s KRAS therapy, Lumakras, totaled $280 million in 2023, while Mirati reported $36 million in sales of its drug, Krazati, through the first nine months of 2023.

Bristol Myers, which closed its deal to buy Mirati in January, recently reported positive results from a confirmatory study of Krazati in lung cancer.