First Patient Dosed in Pivotal Phase III Trial of Cadonilimab (PD-1/CTLA-4) for Perioperative Treatment of Resectable Gastric Cancer

HONG KONG, Aug. 20, 2025 /PRNewswire/ -- 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.

Forward-Looking Statement of Akeso, Inc.

This announcement by Akeso, Inc. (9926.HK, "Akeso") contains "forward-looking statements". These statements reflect the current beliefs and expectations of Akeso's management and are subject to significant risks and uncertainties. These statements are not intended to form the basis of any investment decision or any decision to purchase securities of Akeso. There can be no assurance that the drug candidate(s) indicated in this announcement or Akeso's other pipeline candidates will obtain the required regulatory approvals or achieve commercial success. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in P.R.China, the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; Akeso's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the Akeso's patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

Akeso does not undertake any obligation to publicly revise these forward-looking statements to reflect events or circumstances after the date hereof, except as required by law.

About Akeso

Akeso (HKEX: 9926.HK) is a leading biopharmaceutical company committed to the research, development, manufacturing and commercialization of the world's first or best-in-class innovative biological medicines. Founded in 2012, the company has created a unique integrated R&D innovation system with the comprehensive end-to-end drug development platform (ACE Platform) and bi-specific antibody drug development technology (Tetrabody) as the core, a GMP-compliant manufacturing system and a commercialization system with an advanced operation mode, and has gradually developed into a globally competitive biopharmaceutical company focused on innovative solutions. With fully integrated multi-functional platform, Akeso is internally working on a robust pipeline of over 50 innovative assets in the fields of cancer, autoimmune disease, inflammation, metabolic disease and other major diseases. Among them, 24 candidates have entered clinical trials (including 15 bispecific/multispecific antibodies and bispecific ADCs. Additionally, 7 new drugs are commercially available, and 2 new drugs with 2 new indications are under regulatory review for approval. Through efficient and breakthrough R&D innovation, Akeso always integrates superior global resources, develops the first-in-class and best-in-class new drugs, provides affordable therapeutic antibodies for patients worldwide, and continuously creates more commercial and social values to become a global leading biopharmaceutical enterprise.

For more information, please visit https://www.akesobio.com/en/about-us/corporate-profile/ and follow us on Linkedin.

SOURCE Akeso, Inc.