Bristol-Myers Squibb's Opdivo-Yervoy combo wins right to challenge Merck's Keytruda in rare cancer

Yervoy immuno-therapy packaging
Bristol-Myers Squibb's Yervoy is part of an immuno-oncology duo that won approvals in rare types of colon cancer. (Bristol-Myers Squibb)

Tally another win for Bristol-Myers Squibb’s immunotherapy combination.

Wednesday, the New Jersey drugmaker said its Opdivo-Yervoy pairing grabbed an FDA approval in patients with rare colon cancers that have progressed despite other treatments.

RELATED: Bristol-Myers' Opdivo-Yervoy combo scores again at FDA, this time in colorectal cancer

The green light covers microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) metastatic colorectal cancer. About 4% to 5% of metastatic colorectal cancer patients have those biomarkers, and they’re less likely to benefit from conventional chemotherapy.

While Bristol-Myers already has an approved therapy for that patient group—solo Opdivo nabbed a go-ahead last summer—the company has reason to believe its duo might be more effective. January trial results showed that the combo therapy spurred responses from 55% of patients compared with Opdivo’s 31%, though the study didn’t formally compare the two arms.

RELATED: Bristol-Myers Squibb's Opdivo nabs MSI-H colorectal cancer nod, but it can't match Keytruda's umbrella approval

Now it will be up to Bristol-Myers to launch its new indication against archrival Keytruda from Merck, whose broader approval covers solid tumors in any part of the body as long as they bear the MSI-H genetic features.

Opdivo and Keytruda have been going at it for years, racing to rack up indications and market share. And while Keytruda has emerged as the clear leader in the all-important lung cancer market, BMS last month scored a watershed Chinese approval for Opdivo in that disease, making it the first and only drug in the PD-1/PD-L1 class so far to do so.

Meanwhile, though, Keytruda hasn’t let up on the regulatory front itself. Also Wednesday, Merck said the FDA had granted the drug a priority review in previously treated liver cancer. And if it can win an approval, it’ll go head to head with Opdivo, which already bears that indication.