Neoadjuvant PD-1 Blockade by Toripalimab With or Without Celecoxib in Mismatch-repair Deficient or Microsatellite Instability-high Locally Advanced Colorectal Cancer (PICC)

What this Trial Is About

Researchers are investigating neoadjuvant toripalimab, an anti-PD-1 immunotherapy, with or without celecoxib, in patients with mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) locally advanced colorectal cancer. This type of colorectal cancer represents about 15% of cases and shows limited response to traditional chemotherapy, especially when metastasized. Previous studies demonstrated promising response rates with anti-PD-1 therapies in advanced cases, but neoadjuvant use for this specific group has not yet been explored. The study includes multiple cohorts evaluating different treatment durations and combinations. Patients receive toripalimab intravenously every two weeks at 3 mg/kg for either 6 or 12 cycles. Celecoxib, a cyclooxygenase inhibitor, is given orally twice daily during each cycle in the combination groups. After treatment, surgery may be performed, or patients may undergo non-operative management if complete clinical response is achieved. The trial aims to assess safety, feasibility, and effectiveness in improving pathological complete response rates and event-free survival. Participants will be monitored through imaging scans, laboratory tests, and clinical assessments during treatment and follow-up. Researchers will evaluate outcomes such as pathological complete response within one year, event-free survival over three years, overall survival over five years, and surgical safety and feasibility. The study includes ongoing safety checks and assessments of surgical success, with total treatment cycles and follow-up varying by cohort and treatment response.

Neoadjuvant Toripalimab With or Without Celecoxib in dMMR/MSI-H Colorectal Cancer