HARMONi-6 Data: mPFS 11.14 Months (HR=0.6, P<0.0001) Simultaneously Released at ESMO and in The Lancet

• Ivonescimab plus chemotherapy demonstrated a median PFS of 11.14 months, PFS HR=0.60, P < 0.0001.
• The absolute difference in median PFS between the two groups was 4.24 months (ΔPFS = 4.24 months), indicating significantly prolonged progression-free survival with ivonescimab combination therapy.
• Significant benefits were consistently observed with ivonescimab plus chemotherapy versus tislelizumab combination irrespective of PD-L1 expression.
• Ivonescimab combination therapy showed significant benefit over tislelizumab regimen in patients with or without liver metastases and with or without brain metastases.
• In the HARMONi-6 study, 92.3% of enrolled patients had stage IV disease, and approximately 63% had central-type squamous cell carcinoma.
• Ivonescimab demonstrated a favorable overall safety profile with no new safety signals identified.
• Overall survival (OS) data were not yet mature at the time of this analysis.

HONG KONG, Oct. 19, 2025 /PRNewswire/ -- Akeso (9926.HK) announced the groundbreaking results of the registrational Phase III clinical study (AK112-306/HARMONi-6) evaluating ivonescimab (PD-1/VEGF bispecific antibody), a globally first-in-class bispecific antibody developed by Akeso, in combination with chemotherapy versus tislelizumab combined with chemotherapy as first-line treatment for advanced squamous non-small cell lung cancer (sq-NSCLC). The study results were presented by Professor Lu Shun, Chief of the Shanghai Lung Cancer Center at Shanghai Chest Hospital and Professor of Medicine at Shanghai Jiaotong University, at the 2025 ESMO Presidential Symposium, and the results of the HARMONi-6 clinical trial were simultaneously published in The Lancet.

The HARMONi-6 study met its primary endpoint of progression-free survival (PFS), demonstrating a decisive and strong positive outcome with both statistically significant and clinically meaningful benefits. Ivonescimab plus chemotherapy substantially prolonged sq-NSCLC patient's progression-free survival compared to tislelizumab plus chemotherapy:

• The progression-free survival (PFS) hazard ratio (HR) was 0.60 (p < 0.0001) for ivonescimab plus chemotherapy versus tislelizumab plus chemotherapy. The median PFS was 11.14 months in the ivonescimab combination group versus 6.90 months in the tislelizumab combination group, representing an absolute improvement of ΔPFS = 4.24 months.
• Consistent clinical benefits were observed across all PD-L1 expression subgroups. In the PD-L1 negative (TPS <1%) population, the PFS HR was 0.55 for ivonescimab plus chemotherapy versus tislelizumab plus chemotherapy. In the PD-L1 positive (TPS ≥1%) population, the PFS HR was 0.66 for ivonescimab plus chemotherapy versus tislelizumab plus chemotherapy.
• Regardless of liver or brain metastasis, ivonescimab combined with chemotherapy showed significant benefit over the tislelizumab-based regimen. Among patients with liver metastases, the PFS HR was 0.53; among those without liver metastases, the PFS HR was 0.64. For patients with ≥3 baseline metastatic sites, the PFS HR was 0.46, and for those with <3 baseline metastatic sites, the PFS HR was 0.64.

The ivonescimab group demonstrated a favorable overall safety profile with no new safety signals identified. The incidence of treatment-related serious adverse reactions and grade 3 or higher bleeding events was comparable to the tislelizumab regimen group. The most common adverse reactions were chemotherapy-associated myelosuppression.

The HARMONi-6 study enrolled 532 subjects, with balanced baseline characteristics between the two groups. 92.3% of subjects had clinical stage IV disease. The squamous carcinoma characteristics of enrolled patients reflected real-world clinical presentations, with central-type squamous carcinoma accounting for approximately 63% of the total patients (66.9% in the ivonescimab group vs. 59.4% in the tislelizumab group), consistent with real-world patient distribution. PD-L1 expression levels also reflected those seen in real-world clinical settings.

Approved in 2024, ivonescimab has demonstrated groundbreaking clinical value across dozens of clinical studies and real-world treatments involving over 40,000 patients. In the field of tumor immunotherapy, whether compared with PD-1 monotherapy or PD-1 combination chemotherapy (the current standard of care for many cancers), as well as in the field of anti-angiogenesis therapy compared to VEGF-targeted regimens, ivonescimab has demonstrated robust and superior clinical efficacy, highlighting its exceptional capacity to drive iterative advances in cancer treatment.

The encouraging results from the HARMONi-6 study have led to the review of a supplemental New Drug Application (sNDA) in China for ivonescimab in combination with chemotherapy as a first-line treatment for advanced squamous NSCLC. Meanwhile, the global enrollment for the international, multicenter Phase III HARMONi-3 trial, assessing ivonescimab as a first-line treatment for both squamous (sq-NSCLC) and non-squamous (nsq-NSCLC) non-small cell lung cancer is ongoing. 

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.

source: Akeso, Inc.