First Patient Dosed in Phase III Perioperative Study of Cadonilimab (PD-1/CTLA-4) in Colon Cancer

HONG KONG, Oct. 10, 2026 /PRNewswire/ -- Akeso, Inc. (9926.HK) ("Akeso" or the "Company") announced that the first patient has been dosed in a Phase III clinical study (COMPASSION-40/AK104-313) evaluating cadonilimab, its first-in-class PD-1/CTLA-4 bispecific antibody, as monotherapy in the neoadjuvant/adjuvant (perioperative) treatment of resectable microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) colon cancer.

This marks a significant new indication for cadonilimab beyond gastric, lung, and cervical cancers, and represents the 13th Phase III/registrational study of the therapy conducted globally. Cadonilimab has moved from later-line to first-line treatment of advanced disease and is now being evaluated in the perioperative setting, further broadening its clinical footprint in immuno-oncology (IO) 2.0.

Colorectal cancer is among the malignancies with the highest incidence and mortality worldwide, with colon cancer accounting for most cases. 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 only approximately 7%—a persistent and significant unmet medical need.

In metastatic MSI-H/dMMR colorectal cancer, immune checkpoint inhibitors are already established as the standard of care. In localized disease, perioperative treatment holds the potential for curative intent and the prospect of durable clinical cure—an area of substantial clinical importance and patient value. While multiple exploratory studies of PD-(L)1 monoclonal antibodies in this setting have shown encouraging efficacy signals, no immunotherapy has yet been approved anywhere for the perioperative treatment of localized MSI-H/dMMR colon cancer.

MSI-H/dMMR colon cancer is highly responsive to immunotherapy due to its high tumor mutational burden and inflamed immune microenvironment. However, single-target immune checkpoint inhibitors still leave room for improved outcomes. By dual blockade of the PD-1 and CTLA-4 pathways, cadonilimab is designed to more effectively activate and sustain antitumor immune responses in the perioperative setting. This approach has the potential to increase rates of major pathological response (MPR) and pathological complete response (pCR), thereby lowering the risk of postoperative recurrence and improving long-term survival.

Supporting evidence comes from a prior Phase II study of cadonilimab monotherapy as neoadjuvant treatment in patients with MSI-H/dMMR colorectal cancer. Data presented at the 2024 ESMO Immuno-Oncology Congress showed a pathological complete response (pCR) rate of 84.6% and a major pathological response (MPR) rate of 100% among patients who proceeded to surgery, with a manageable safety profile.

As the first approved checkpoint bispecific antibody for cancer, cadonilimab has shown consistent clinical benefit across a broad range of patients, including both PD-L1-positive and PD-L1-negative individuals, in extensive real-world use and multiple Phase III trials. It is increasingly recognized as a foundational therapy in the immuno-oncology (IO) 2.0 era. Cadonilimab is currently being evaluated in 13 Phase III/registrational studies worldwide across major indications such as lung, gastric, cervical, liver and colon cancers, spanning first-line, second-line, perioperative, adjuvant and consolidation settings.

About Cadonilimab

Cadonilimab is a first-in-class PD-1/CTLA-4 bispecific antibody developed by Akeso for cancer immunotherapy. In June 2022, it received initial marketing approval from China's National Medical Products Administration (NMPA) for the treatment of patients with relapsed or metastatic cervical cancer who had progressed on or after platinum-based chemotherapy. In September 2024, cadonilimab was approved in combination with fluoropyrimidine- and platinum-based chemotherapy for the first-line treatment of patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma. In May 2025, cadonilimab plus platinum-based chemotherapy, with or without bevacizumab, was approved for the first-line treatment of persistent, recurrent, or metastatic cervical cancer.

By simultaneously targeting PD-1 and CTLA-4, cadonilimab delivers synergistic antitumor activity. It has shown robust efficacy with markedly lower toxicity and improved tolerability compared with conventional combination regimens, demonstrating potent activity across multiple tumor types independent of PD-L1 expression and offering breakthrough clinical value in immunotherapy-resistant and "cold" tumors.

To date, cadonilimab has been evaluated in more than 40 clinical studies spanning over 20 indications, including gastric, lung, liver, cervical, and pancreatic cancers. Thirteen Phase III/registrational studies are ongoing; three have met their primary endpoints; and two global Phase III/registrational trials are advancing.

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, Akeso has built a comprehensive R&D innovation ecosystem anchored by its proprietary Tetrabody antibody technology platform, AI-powered drug R&D platform, Dual-Shield ADC technology platform, Dual-Lock T-cell engager (TCE) technology platform, Tissue-Smart siRNA/mRNA technology platform, and cell therapy technology platforms.

Backed by world-class GMP manufacturing facilities and a highly efficient, integrated commercialization system, Akeso has developed into a globally competitive biopharmaceutical enterprise. Leveraging its fully integrated, multi-functional platform, the Company maintains a robust pipeline of more than 50 innovative assets targeting cancer, autoimmune diseases, inflammation, metabolic disorders, and other major therapeutic areas. Of these, nearly 30 candidates have advanced into clinical trials, including 15 bispecific or multi-specific antibodies and bispecific ADCs. Eight innovative drugs are commercially available, and two additional drugs with three indications are currently under regulatory review for marketing approval.

Akeso is committed to becoming a global leader in biopharmaceuticals through efficient and breakthrough innovation in R&D, developing novel therapies that are first-in-class or best-in-class, and providing better disease solutions for patients around the world.

Forward-Looking Statements

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 the 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 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.

SOURCE Akeso, Inc.