Akeso, Inc. has dosed the first patient in a Phase III study of cadonilimab as monotherapy in the neoadjuvant and adjuvant treatment of resectable microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) colon cancer, the company said. The trial is designated COMPASSION-40/AK104-313, and the treatment covers the period before and after surgery, known as the perioperative setting.
The study is the 13th Phase III or registrational trial of the therapy conducted globally and adds an indication for cadonilimab beyond gastric, lung and cervical cancers. Akeso said the antibody is being evaluated in 13 Phase III or registrational studies worldwide across lung, gastric, cervical, liver and colon cancers, spanning first-line, second-line, perioperative, adjuvant and consolidation settings. Three of those studies have met their primary endpoints, and two global Phase III or registrational trials are advancing.
Akeso said colorectal cancer is among the cancers with the highest incidence and mortality worldwide, with colon cancer accounting for most cases, and that perioperative outcomes are a major determinant of long-term prognosis. Patients with MSI-H/dMMR colon cancer derive limited benefit from conventional perioperative chemotherapy, with pathological response rates of about 7%, it said. In metastatic MSI-H/dMMR colorectal cancer, immune checkpoint inhibitors are already established as the standard of care, while no immunotherapy has been approved anywhere for the perioperative treatment of localized MSI-H/dMMR colon cancer.
The company pointed to a prior Phase II study of cadonilimab monotherapy as neoadjuvant treatment in MSI-H/dMMR colorectal cancer. Data presented at the 2024 ESMO Immuno-Oncology Congress showed a pathological complete response rate of 84.6% and a major pathological response rate of 100% among patients who proceeded to surgery, with a manageable safety profile, Akeso said.
Cadonilimab received initial marketing approval from China's National Medical Products Administration in June 2022 for patients with relapsed or metastatic cervical cancer who had progressed on or after platinum-based chemotherapy. In September 2024 it was approved in combination with fluoropyrimidine- and platinum-based chemotherapy for first-line treatment of locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma, and in May 2025 it was approved with platinum-based chemotherapy, with or without bevacizumab, for first-line treatment of persistent, recurrent or metastatic cervical cancer.
