MSI-H/dMMRCadonilimab as Neoadjuvant Therapy in Resectable Stage II-III Mismatch Repair-deficient (dMMR)/ Microsatellite Instability-high (MSI-H) Colorectal Cancer

Colorectal cancer (CRC) is one of the most common malignant tumours of human beings. Mismatch Repair-deficient (dMMR)/ Microsatellite Instability-high (MSI-H) CRC is a specific subtype of CRC, which accounts for approximately 15% \~20% of all CRC patients,and can not benefit from 5-fluorouracil (5-FU) adjuvant chemotherapy. Once patients have distant metastases, they are not sensitive to traditional palliative chemotherapy, and thus lead to much worse prognosis than that of mismatch repair-proficient (pMMR)/ microsatellite stability (MSS). Neoadjuvant immunotherapy based on mismatch repair (MMR) status in CRC have reported some encouraging data. The NICHE study showed that 20 CRC patients with dMMR achived pathological remission, of which 19 patients with residual tumor ≤10%, 15 patients achived pathological complete remission. Another study (ClinicalTrials.gov, NCT03926338) which investigating the effect of neoadjuvant PD-1 blockade with toripalimab, with or without celecoxib, on mismatch repair-deficient or microsatellite instability-high, locally advanced, colorectal cancer. The result revealed that all 34 patients had an R0 resection. 15 of 17 patients (88%) in the toripalimab plus celecoxib group and 11 of 17 patients (65%) in the toripalimab monotherapy group had a pathological complete response. Cadonilimab (®), a PD-1/CTLA-4 bi-specific antibody, is being developed by Akeso, Inc. for the treatment of a range of solid tumours, including cervical cancer, lung cancer, gastric/gastroesophageal junction cancer, oesophageal squamous cell cancer, liver cancer and nasopharyngeal cancer. Cadonilimab was approved in China in June 2022 for use in patients with relapsed or metastatic cervical cancer (r/mCC) who have progressed on or after platinum-based chemotherapy. Given the reported efficacy data about immunotherapy as neoadjuvant treatment in MSI-H/dMMR CRC, the aim of this study was to investigate the efficacy and safety of Cadonilimab as neoadjuvant treatment for resectable local advanced colorectal cancer patient with the dMMR/MSI-H.