Updated Efficacy Data of Ivonescimab Combined with Chemotherapy as First-Line Treatment for TNBC Presented at ESMO IO 2025

HONG KONG, Dec. 10, 2025 /PRNewswire/ -- Akeso, Inc. (9926.HK) ("Akeso" or the "Company") announced the presentation of a Phase II clinical study that included a longer-term efficacy data evaluating ivonescimab (a PD-1/VEGF bispecific antibody) combined with chemotherapy as a first-line treatment for locally advanced unresectable or metastatic triple-negative breast cancer (TNBC) at the 2025 European Society for Medical Oncology Immuno-Oncology Congress (ESMO IO) in London, UK.

Based on positive efficacy and safety profile, the ivonescimab combination therapy for first-line TNBC was previously included in the Breakthrough Therapy Designation (BTD) list by the Center for Drug Evaluation (CDE) of China's National Medical Products Administration (NMPA). Currently, the multicenter, randomized, double-blind Phase III clinical trial (HARMONi-BC1/AK112-308) for this indication is currently ongoing.

Preliminary results from this study were previously announced at the European Society for Medical Oncology (ESMO) Congress 2024 and the 2024 San Antonio Breast Cancer Symposium (SABCS). With the follow-up period now extended to 22.1 months, the study further validates the efficacy and safety profile of the ivonescimab regimen in first-line TNBC treatment.

As of July 15, 2025, a total of 36 patients with TNBC were enrolled. The median age was 55 years, 83.3% of patients had a PD-L1 combined positive score (CPS) <10, and 55.6% had received prior taxane-based neo/adjuvant therapy. As of the data cutoff, 35 patients had undergone at least one post-baseline tumor assessment and were included in the efficacy analysis set. The results showed that the ivonescimab combined with chemotherapy regimen demonstrated efficient tumor relief, disease control, and survival benefits in all PD-L1 subgroups of TNBC patients receiving first-line treatment. The key results are:

• The objective response rate (ORR) for the overall population was 80.0%, the disease control rate (DCR) was 100.0%, and the median duration of response (mDOR) was 12.2 months; the median progression-free survival (mPFS) was 15.2 months, with a 12-month PFS rate of 56.3%.
• In the CPS≥10 subgroup, the ORR was 83.3%, the DCR was 100%, the mDOR was 12.2 months; the mPFS was 15.9 months, with a 12-month PFS rate of 66.7%.
• In the CPS<10 subgroup, the ORR was 79.3%, the DCR was 100%, the mDOR was 9.9 months; the mPFS was 13.04 months, with a 12-month PFS rate of 54.3%.
• In the CPS≥1 subgroup, the ORR was 72.2%, the DCR was 100%, the mDOR was 12.2 months; the mPFS was 15.9 months, with a 12-month PFS rate of 63.8%.
• Overall survival (OS) data is not yet mature.
• Ivonescimab combined with chemotherapy as first-line treatment for TNBC demonstrated a good safety profile. No treatment-related adverse events (TRAEs) led to discontinuation or death in this study, and the most common TRAEs were mostly grade 1-2.

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, 26 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.

SOURCE Akeso, Inc.