Checkpoint Inhibitor Combo Boosts Survival in MSI-H Metastatic Colorectal Cancer

The CheckMate 8HW trial reveals that the combination of nivolumab and ipilimumab significantly improves progression-free survival in patients with microsatellite-instability–high (MSI-H) or mismatch-repair–deficient (dMMR) metastatic colorectal cancer compared to chemotherapy. In a cohort of 303 treatment-naïve patients, the 24-month progression-free survival rate was 72% with the combination therapy, markedly higher than 14% with chemotherapy. The dual immunotherapy approach also reduced the incidence of severe treatment-related adverse events (23% vs. 48% with chemotherapy). These findings underscore the potential of nivolumab plus ipilimumab as a first-line treatment for MSI-H/dMMR metastatic colorectal cancer, offering a less toxic and more effective alternative to conventional chemotherapy.