Merck looks for leg up on Bristol with Keytruda's latest colorectal cancer win

Merck’s Keytruda went up against chemo in a head-to-head colorectal cancer battle—and won.

The immuno-oncology star trumped various chemo regimens at keeping cancer from progressing in previously untreated patients with microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) colorectal cancer that had either spread to other parts of the body or couldn’t be surgically removed, the New Jersey drugmaker said Tuesday.

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As Merck was quick to note, the trial, Keynote-177, was the first phase 3 trial to successfully pit a single-agent therapy against the standard of care—a combination of Roche’s Avastin and a chemo regimen known as mFOLFOX6. “We look forward to sharing these data as quickly as possible with the medical community and regulatory authorities,” Roy Baynes, Merck SVP and global head of clinical development, said in a statement.

In the meantime, the study will continue to see if Keytruda can extend patient lives to hit its second primary endpoint.

An approval for Keytruda in the previously untreated group would broaden the reach it already has in MSI-H and dMMR tumors. Back in May 2017, it picked up an FDA green light in previously treated patients whose tumors bore those biomarkers, no matter where the tumors were located within the body.

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It would also give Keytruda a leg up over rival Bristol Myers Squibb rival Opdivo in the colorectal field. The BMS contender boasts its own approval for previously treated MSI-H or dMMR colorectal cancer, but it hasn’t yet broken into the front-line setting.

That doesn’t mean it’s not trying. In October 2018, Bristol rolled out phase 2 results showing its Opdivo-Yervoy pairing could provoke responses in 60% of first-line MSI-H or dMMR colorectal cancer patients, a result BMS’ oncology development chief, Fouad Namouni, called “groundbreaking.”