Immunotherapy Plus Checkpoint Inhibition in Recruiting Colorectal Cancer Trial

A landmark Phase III trial (NCT05112354) is currently recruiting patients with mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) metastatic colorectal cancer. The trial evaluates the combination of nivolumab (PD-1 inhibitor) and ipilimumab (CTLA-4 inhibitor) as first-line therapy.

Trial Design

The randomized, open-label trial enrolls adult patients with confirmed dMMR/MSI-H metastatic colorectal cancer who have not received prior systemic therapy for metastatic disease. Participants are randomized 1:1 to receive the combination immunotherapy or standard FOLFOX-based chemotherapy.

Preliminary Results

An interim safety analysis reported at ASCO 2024 demonstrated a 67% objective response rate in the immunotherapy arm versus 38% in the chemotherapy arm. Grade 3–4 immune-related adverse events occurred in 22% of participants and were manageable with standard immunosuppression protocols.

Significance

Colorectal cancer with dMMR/MSI-H status represents approximately 5% of metastatic cases. This biomarker-selected population has demonstrated exceptional responsiveness to immunotherapy, with some patients achieving durable complete responses.