Akeso, Inc. (9926.HK) ("Akeso" or the "Company") announced the enrollment and dosing of the first patient in the pivotal Phase III clinical trial (AK104-310/COMPASSION-33) evaluating cadonilimab, a first-in-class PD-1/CTLA-4 bispecific antibody developed by Akeso, in combination with chemotherapy for the perioperative treatment of resectable gastric/gastroesophageal junction (G/GEJ) adenocarcinoma.

The COMPASSION-33 study represents the third Phase III trial for cadonilimab in gastric cancer. The study aims to improve the radical resection rate in patients with advanced gastric cancer, reduce the risk of recurrence and metastasis, and enhance overall patient outcomes. This study broadens cadonilimab's clinical application from unresectable advanced gastric cancer to also include resectable advanced gastric cancer, potentially expanding the number of gastric cancer patients that can benefit from its synergistic and simultaneous targeting of PD-1 and CTLA-4 checkpoints.

Cadonilimab, in combination with chemotherapy, has already been approved for the first-line treatment of advanced gastric cancer in China, showing efficacy for patients with tumors across all levels of PD-L1 expression, including those with high, low, and negative PD-L1 expression. Additionally, a Phase III registration trial is currently underway to evaluate the combination of cadonilimab with pulocimab (VEGFR-2) for treating immune therapy (IO)-resistant advanced gastric cancer. This study aims to provide a new, effective second-line treatment option for patients with IO resistance, further demonstrating cadonilimab's potential to address critical unmet need in this difficult to treat cancer patient populations.

Currently, there are no approved perioperative immunotherapy regimens in the world, highlighting a significant unmet need. Preliminary data suggest that cadonilimab may offer superior efficacy and a more favorable safety profile compared to existing PD-1 therapies for the perioperative treatment of G/GEJ adenocarcinoma. As the world's first approved and commercially available PD-1/CTLA-4 bispecific antibody, cadonilimab has already demonstrated superior efficacy compared to other treatment options in a Phase III trial for the first-line treatment of advanced G/GEJ adenocarcinoma. Cadonilimab's ability to meaningfully improve survival outcomes and significantly reducing risk of death for patients across all levels of PD-1 expression is particularly meaningful. Whereas current approved PD-1 treatments have demonstrated very limited or no survival benefit for patients with G/GEJ tumors that have low or negative PD-L1 expression, cadonilimab has demonstrated clinically meaningful survival benefit even in this difficult to treat patient population.  Moreover, in patients with higher levels of PD-L1 expression, cadonilimab has demonstrated superior overall survival benefits compared to other approved PD-1 treatments in the first-line treatment of advanced G/GEJ.