Merck's Keytruda lands new colorectal cancer nod, its 2nd biomarker-based OK this month

Merck's Keytruda now has two approvals in the last seven days. (Merck)

After Keytruda posted practice-changing colorectal cancer data at this year’s virtual American Society of Clinical Oncology meeting, it was only a matter of time before the Merck superstar snagged a new indication. And that time has come.

The FDA Monday greenlighted Merck’s immuno-oncology med in previously untreated patients with metastatic or inoperable colorectal cancer and one of two biomarkers—microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) tumors.

The nod is the first for a drug in Keytruda’s class; rival Opdivo from Bristol Myers Squibb boasts a nod in second-line patients, while Keytruda itself is cleared to treat second-line patients with MSI-H or dMMR tumors anywhere in the body.

“Today’s approval has the potential to change the treatment paradigm for the first-line treatment of patients with MSI-H colorectal cancer,” Roy Baynes, senior vice president and global head of clinical development, said in a statement.

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The agency based its decision on results showing Keytruda could stave off cancer progression for 16.5 months, versus just 8.2 months for chemo. That performance helped cut patients’ risk of disease worsening or death by 40%.

"That's a pretty significant improvement," Jonathan Cheng. M.D., vice president of oncology clinical development at Merck Research Laboratories, said at the time.

The go-ahead is Keytruda’s second this month to be driven by biomarkers. In mid-June, the FDA gave Keytruda the OK in previously treated patients with high levels of the biomarker tumor mutational burden.

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“Our commitment to pursuing biomarker research continues to help us bring new treatments to patients, particularly for those who have few available options,” Baynes said in the statement.

It’s also the drug’s second approval in a week after the FDA last Wednesday approved Keytruda in patients with cutaneous squamous cell carcinoma, where it will challenge Sanofi and Regeneron's checkpoint inhibitor, Libtayo.