AI Insight
This Lancet commentary discusses the NICHE-2 phase 2 clinical trial, which tested preoperative immunotherapy in patients with early-stage mismatch repair-deficient colon cancer. The trial administered ipilimumab and nivolumab before surgery to patients with clinical stage II and III disease, resulting in a 98% pathologic response rate and 68% achieving complete pathologic response. These results challenge the decades-long standard treatment approach of surgery followed by adjuvant chemotherapy for early-stage colon cancer.
Why it matters
The findings suggest that neoadjuvant immunotherapy could potentially replace or reduce the need for traditional chemotherapy in patients with mismatch repair-deficient colon cancer, which represents 10-15% of non-metastatic cases. This approach may offer improved outcomes with potentially fewer side effects, fundamentally changing treatment paradigms for this subset of colon cancer patients.
Understand the Science
For decades, the standard of care for patients with resected stage II and III colon cancer has centred on surgery with consideration of postoperative adjuvant systemic therapy to reduce risk of recurrence. Mismatch repair deficiency is seen in 10–15% of non-metastatic colon cancers and is predictive of response to immune checkpoint inhibition. The initial report of the single-arm, phase 2 NICHE-2 study of one dose of ipilimumab (1 mg per kg) and two doses of nivolumab (3 mg per kg) before surgery with clinical stage II and III colon cancer generated considerable interest after demonstrating a remarkable 98% pathologic response rate, including a pathologic complete response rate of 68%.
Source: [Comment] Redefining curative treatment for early-stage mismatch repair-deficient colon cancer