Akeso Initiates Phase III Study of Cadonilimab in Colon Cancer

Akeso, Inc. announced that the first patient has been dosed in a Phase III clinical study of cadonilimab, a bispecific antibody targeting PD-1 and CTLA-4. The study will evaluate cadonilimab as monotherapy in the neoadjuvant/adjuvant (perioperative) treatment of resectable microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) colon cancer.

This trial represents a significant expansion for cadonilimab, which has previously been studied in gastric, lung, and cervical cancers. The company notes that colon cancer patients with MSI-H/dMMR often show limited benefit from conventional perioperative chemotherapy, indicating an unmet medical need.

The company's approach with cadonilimab aims to enhance anti-tumor immune responses by dual blockade of PD-1 and CTLA-4 pathways. This strategy is intended to increase major pathological response rates, potentially reducing postoperative recurrence and improving long-term survival.

Previous Phase II study data showed a pathological complete response (pCR) rate of 84.6% and a major pathological response (MPR) rate of 100% in patients undergoing surgery. Cadonilimab has existing approvals for the treatment of cervical and gastric cancers.