Opdivo approved for subtype of colorectal cancer

From 5% to 15% of people colorectal cancer have the MSI-H subtype

CANCER DIGEST – April 12, 2025 – The FDA this week approved another indication for the drug nivolumab (Opdivo®) used in combination with ipilimumab (Yervoy®) for treatment of a subtype of colorectal cancer.

Nivolumab (pronounced ni-vol-you-mab) is an immunotherapy that stimulates the immune system to fight cancer. It has been previously approved for several types of cancer including melanoma, lung cancer, head and neck cancers and Hodgkin’s lymphoma. 

In this case the FDA approved the drug to be used in combination with another immunotherapy drug for treatment of unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) colorectal cancer (CRC). This is a unique subgroup of cancers of the colon and rectum that make up 5% to 15% of all colorectal cancers. These are colorectal tissues that lack or have a dysfunctional DNA mutation that affects the repair mechanism of the cells. 

The FDA approval followed the results of a large comparison trial involving 839 patients randomly assigned to one of three treatment regimens. One group received nivolumab 240 mg every 3 weeks and ipilimumab 1 mg/kg every 3 weeks for a maximum of 4 doses, then nivolumab 480 mg every 4 weeks. A second group received nivolumab alone every two weeks up to 6 doses and then nivolumab every 4 weeks. The third group received chemotherapy.

Effectiveness of each treatment was measured by progression-free survival, or the length of time a person survived without the cancer worsening. In the combination nivolumab plus ipilimumab group the median progression-free survival had not been reached at 53.8 months. In other words, by the end of the trial people were still surviving without their cancer progressing. In the nivolumab alone group progression-free survival was 39.3 months, and PFS was 20.9 months for the chemotherapy group.

Based on these results and earlier results of two other trials, the FDA granted marketing approval for the combination therapy using nivolumab and ipilimumab. Both drugs are made by Bristol Myers Squibb.

The most common side effects were fatigue, diarrhea, pruritus (itching), abdominal pain, musculoskeletal pain, and nausea.

Sources: FDA press release, and The ASCO Post