Significant OS Benefit with Cadonilimab in First-Line Advanced Gastric Cancer: Final Analysis of COMPASSION-15 Presented at ESMO 2025

Significant OS Benefit with Cadonilimab in First-Line Advanced Gastric Cancer: Final Analysis of COMPASSION-15 Presented at ESMO 2025

HONG KONG, Oct. 19, 2025 /PRNewswire/ -- On October 19, 2025, Akeso (9926.HK) announced the final analysis results from the COMPASSION-15/AK104-302 study at the 2025 European Society of Medical Oncology Congress (ESMO 2025) .  COMPASSION-15 is a Phase III clinical trial evaluating cadonilimab, Akeso's first-in-class PD-1/CTLA-4 bispecific antibody, in combination with oxaliplatin and capecitabine as first-line treatment for unresectable, locally advanced, recurrent, or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma.  Professor Shen Lin, principal investigator from Peking University Cancer Hospital, presented the findings in an oral session at ESMO 2025.

In this final analysis presented at ESMO 2025 (median follow-up: 33.9 months), the cadonilimab regimen demonstrated enhanced long-term survival benefits in first-line advanced G/GEJ adenocarcinoma. With the extended follow-up period and more mature data, the cadonilimab treatment regimen showed a further reduction in the risk of death compared to the control group. This consistent benefit was observed across all PD-L1 expression subgroups.

The interim analysis of COMPASSION-15, with a median follow-up of 18.7 months, was previously published in Nature Medicine in January 2025. The data presented at ESMO 2025 were analyzed using the same statistical methodology.

COMPASSION-15 2025 ESMO Data

In the intent-to-treat (ITT) population:

• With long-term follow-up, the cadonilimab regimen demonstrated a significant 39% reduction in the risk of death (OS HR 0.61) versus the control group, showing further improvement over the data from the median 18.7-month follow-up (OS HR 0.66).
• With extended follow-up, in the PD-L1 CPS ≥5 population, the cadonilimab regimen demonstrated a significant 51% reduction in the risk of death (OS HR 0.49; p < 0.001) compared to the control group, showing further improvement over the data from the median 18.7-month follow-up (OS HR 0.58).
• With long-term follow-up, in the PD-L1 CPS <5 population, the cadonilimab regimen showed a significant 24% reduction in the risk of death (OS HR 0.76; 95% CI: 0.59-0.99; p = 0.019) versus the control group, with a strengthening trend of benefit compared to the data from the median 18.7-month follow-up (OS HR 0.75; 95% CI: 0.56-1.00).
• Following extended the follow-up period, the cadonilimab combination regimen maintained a favorable safety profile, with no new safety signals emerging.

In the COMPASSION-15 study, patients with PD-L1 CPS <5 (low expression) and CPS <1 (negative expression) are 49.8% and 23%, respectively, of the ITT population. This represents a higher proportion of PD-L1 low and negative patient population in COMPASSION-15 compared to previous Phase III trials of other immune checkpoint inhibitors used in the treatment of first-line gastric cancer. Previous studies have shown limited responses to PD-1/L1 inhibitors in PD-L1 low-expression or negative patients.

Cadonilimab was approved by the NMPA in September 2024 for the first-line treatment for advanced gastric cancer, offering a new and effective immunotherapy option. Cadonilimab has been included in the 2025 CSCO Gastric Cancer Guidelines as the only Category I recommendation (Level 1A evidence) for first-line immunotherapy, regardless of PD-L1 expression, and is currently widely used in clinical practice.

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. 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.

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