Ivonescimab HARMONi-A Study Final OS Analysis Results Presented at SITC 2025 with OS HR=0.74

• The HARMONi-A study is the first Phase III trial of an immunotherapy for EGFR-TKI-resistant, EGFR-mutated non-squamous NSCLC to show statistically significant and clinically meaningful improvements in both progression-free survival (PFS) and overall survival (OS)
• With a median follow-up of 32.5 months, the ivonescimab combination regimen showed a median OS of 16.8 months, versus 14.1 months for chemotherapy (OS HR=0.74, P=0.019)
• The OS benefit of the ivonescimab combination regimen was consistent across all subgroups, showing significant improvement regardless of the presence of brain metastases or EGFR mutations (19Del and L858R)
• During the 32.5-month follow-up period, the ivonescimab combination regimen demonstrated excellent safety
• These are the final and only formal OS analysis results from the HARMONi-A study
• Ivonescimab was approved for market launch in China in May 2024 and was added to the National Reimbursement Drug List (NRDL) in November 2024

HONG KONG, Nov. 7, 2025 /PRNewswire/ -- Akeso, Inc. (HKEX: 9926.HK) is excited to announce that the final Overall Survival (OS) analysis results from the HARMONi-A study, a Phase III study evaluating ivonescimab combined with chemotherapy for the treatment of EGFR-mutated non-squamous non-small cell lung cancer (nsq-NSCLC) following EGFR-TKI progression, were selected as a "Late-Breaking Abstract" (LBA) for the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), held in National Harbor, Maryland, USA. Professor Xiuning Le from MD Anderson Cancer Center presented these findings to a global audience during an oral presentation session.

HARMONi-A is the first global Phase III clinical trial of an immunotherapy in the EGFR-TKI resistant, EGFR-mutated nsq-NSCLC setting to demonstrate clinically meaningful and statistically significant benefits in both Progression-Free Survival (PFS) and Overall Survival (OS). This final OS analysis, the first from a Phase III trial of ivonescimab, confirms the breakthrough value of ivonescimab-based therapy in improving both PFS and OS. Historically, cancer immunotherapies have largely failed to demonstrate significant breakthroughs in this specific indication. Prior Phase III trials involving other regimens—such as PD-1 inhibitors combined with chemotherapy or immunotherapies combined with anti-angiogenic therapy, failed to show significant OS benefits. The significant positive outcomes in both PFS and OS in the HARMONi-A study underscore the substantial clinical benefit improvement of ivonescimab over PD-1 inhibitors.

Previously, the HARMONi-A study had already met its primary endpoint, demonstrating a statistically significant improvement in PFS at the interim analysis (PFS HR 0.46, P < 0.001). Previously, during the regulatory review for the approval of ivonescimab in first-line PD-L1-positive NSCLC in China, a descriptive analysis of OS from the HARMONi-A study was conducted in May 2024 at the request of the regulatory authorities. The final OS analysis results presented at SITC 2025 represent the final and only pre-specified formal OS analysis for the HARMONi-A study, performed as a sequential test according to the pre-specified statistical analysis plan (SAP).

The final OS analysis, with a median follow-up period of 32.5 months, showed that the ivonescimab plus chemotherapy regimen provided a clinically meaningful and statistically significant improvement in OS compared to chemotherapy alone:

• The median OS was 16.8 months in the ivonescimab treatment group compared to 14.1 months in the control group (OS HR=0.74, P=0.019), achieving statistical significance. The OS benefit increased with extended follow-up.
• The ivonescimab combination regimen consistently demonstrated OS benefit over the control group across all subgroups:
  • In patients with brain metastases, OS HR=0.61;
  • In patients without brain metastases, OS HR=0.77;
  • In patients with EGFR 19Del mutations, OS HR=0.83;
  • In patients with EGFR L858R mutations, OS HR=0.60.

With a median follow-up of 32.5 months, the long-term safety profile of the ivonescimab combination therapy remained favorable, with no new safety signals identified. The incidence of common treatment-related adverse events (TRAEs) showed no significant difference between the two groups.

Based on the positive clinical data from the HARMONi-A study, ivonescimab received approval from the China National Medical Products Administration in May 2024 for this indication. In November 2024, Akeso announced that ivonescimab was successfully added to China's National Reimbursement Drug List, effective January 1, 2025, ensuring widespread patient access to this life-saving treatment.

Additionally, Summit Therapeutics, Akeso's global partner for ivonescimab, announced in October 2025 that it plans to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) in the fourth quarter of 2025, seeking approval for ivonescimab in combination with chemotherapy for the treatment of EGFR-mutant, third-generation EGFR-TKI-resistant, non-squamous NSCLC.

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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