BMS and Pfizer Make Strides in Colorectal Cancer Treatment with Promising Phase III Results

Bristol Myers Squibb (BMS) and Pfizer have unveiled new late-stage data at the 2025 American Society of Clinical Oncology Gastrointestinal Cancer Symposium (ASCO GI) in San Francisco, potentially establishing their respective cancer therapies as new standards of care in specific colorectal cancer subtypes.

BMS's Opdivo-Yervoy Combination Shows Strong PFS Benefit

In the Phase III CheckMate -8HW trial, BMS's PD-1 inhibitor Opdivo (nivolumab), when combined with the company's anti-CTLA4 antibody Yervoy (ipilimumab), demonstrated significant progression-free survival (PFS) benefits in patients with microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC).

After a median follow-up of 47 months, the Opdivo-Yervoy combination reduced the risk of death or disease progression by 38% compared to Opdivo monotherapy, with a p-value of 0.0003. The overall response rate (ORR) was also notably higher in the combination arm, reaching 71% versus 58% for Opdivo alone.

While the combination therapy showed a higher incidence of grade 3 or 4 treatment-related adverse events (22% vs. 14% for monotherapy), BMS reported that the safety profile remained consistent with previous findings, with no new signals of concern.

Thierry Andre, head of the Medical Oncology department at Sorbonne University, stated that these findings "confirm nivolumab plus ipilimumab as a new standard treatment for people living with metastatic colorectal cancer." Andre has disclosed receiving honoraria from BMS and acting as a consultant or advisor to the company.

Pfizer's Braftovi Combination Shows Promise in BRAF V600E-Mutant mCRC

Pfizer announced that its oral kinase inhibitor Braftovi (encorafenib), when used in combination with cetuximab and the mFOLFOX6 chemotherapy regimen, demonstrated significant ORR improvements in mCRC patients with the V600E mutation in the BRAF gene.

The Braftovi combination yielded a 60.9% ORR, compared to 40% in patients receiving chemotherapy with or without bevacizumab. This difference was statistically significant, with a p-value of 0.0008. The median duration of response was 13.9 months in the Braftovi arm, versus 11.1 months in the control group.

While overall survival data were still immature, Pfizer reported a trend favoring the Braftovi combination. The safety profile of the combination therapy was consistent with the known side effects of each agent, with serious adverse events approximately balanced between treatment groups.

Scott Kopetz, deputy chair of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center and co-principal investigator of the Pfizer study, suggested that these findings potentially position the Braftovi regimen as "the new standard of care for people with BRAF V600E-mutant metastatic colorectal cancer, for whom long-term disease control is critical."

These developments from BMS and Pfizer represent significant advancements in the treatment of specific subtypes of metastatic colorectal cancer, offering new hope for patients and potentially reshaping the standard of care in this challenging disease area.