Immunotherapy for patients with colorectal cancer

Microsatellite unstable (MSI) colorectal cancers (CRC) are due to DNA mismatch repair deficiency (sporadic or Lynch syndrome) and occurs in 5% (metastatic, mCRC) and 10-15% (non- metastatic, nmCRC) cases. Immune checkpoints inhibitors have revolutionized the management of patients with MSI mCRC. Since 2020 pembrolizumab (anti-PD1) is the new standard of care for these group of patients with 42,7% free from disease progression at 3 years. In 2025, one phase III trial showed that nivolumab (anti-PD1) plus ipilimumab (anti-CTA4) significantly prolongs progression-free survival compared with nivolumab alone, with 70% of patients with MSI mCRC in the combination arm free from disease progression at 3 years, with the hope of being cured. Accumulating regarding the efficacy of neoadjuvant immune checkpoints inhibitors for patients with nmCRC, with at least two-thirds of patients in different trials in pathological complete response, making it possible to envisage « Watch and Wait » strategies, especially for rectal cancer.
Thierry André, Sorbonne Université, Department of Medical Oncology, Saint-Antoine Hospital, AP-HP, Paris, France