HARMONi-6 Demonstrates Significant Overall Survival Benefit (HR=0.66): Ivonescimab Plus Chemotherapy Superior to PD-1 Plus Chemotherapy in First-Line sq-NSCLC Landmark Results to Be Presented at ASCO 2026 Plenary Session

CHICAGO, May 31, 2026 /PRNewswire/ -- Akeso, Inc. (9926.HK) ("Akeso" or the "Company") today announced that ivonescimab, the Company's first-in-class PD-1/VEGF bispecific antibody, has achieved a statistically significant and clinically meaningful improvement in overall survival (OS) as a first-line treatment for patients with advanced squamous non-small cell lung cancer (sq-NSCLC) in the Phase III HARMONi-6 (AK112-306) study. These landmark findings will be featured in a Plenary Session at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. Professor Shun Lu, Director of the Lung Cancer Center at Shanghai Chest Hospital and Principal Investigator of HARMONi-6, presented the data in an oral Plenary Session presentation.

This marks the first time a China-originated investigational oncology drug has been selected for the ASCO Plenary Session in the society's 61-year history. This moment is a definitive testament to the ivonescimab regimen's role in ushering cancer immunotherapy into the '2.0 Era'.

The HARMONi-6 study results were simultaneously published in The Lancet.

The HARMONi-6 study enrolled a total of 532 patients. Among them, approximately 63% had centrally located squamous tumors, 39.0% had PD-L1 TPS <1%, and 33.8% had multi-site metastases, liver metastases, or brain metastases. At the pre-specified interim analysis, as assessed by the Independent Data Monitoring Committee (IDMC), the study met its key secondary endpoint of overall survival (OS), demonstrating both clinically a meaningful and statistically significant benefit.

As of the data cutoff date of February 27, 2026, with a median follow-up of 21.36 months:

34% reduction in the risk of death - ivonescimab plus chemotherapy significantly prolonged OS

• In the intent-to-treat (ITT) population, ivonescimab plus chemotherapy reduced the risk of death by 34% versus tislelizumab plus chemotherapy (HR=0.66 [95% CI: 0.50–0.87], P=0.0017(＜0.0049). Median OS was 27.9 months in the ivonescimab arm (the final death event in this arm caused the Kaplan-Meier curve to drop sharply to the median, thereby producing the mOS estimate) versus 23.7 months in the control arm.
• The 12-month OS rate was 78.9% with ivonescimab plus chemotherapy versus 72.2% in the control arm, and the 24-month OS rate was 64.7% versus 48.6%, respectively. The survival benefit continued to widen over time, reflecting a more durable and clinically meaningful long-term survival advantage.

Consistent OS benefit across all prespecified subgroups

• OS benefit with ivonescimab was observed consistently regardless of PD-L1 expression status: HR=0.68 in the PD-L1 TPS ≥1% subgroup and HR=0.64 in the TPS <1% subgroup; HR=0.67 in the PD-L1 TPS 1–49% subgroup and HR=0.64 in the TPS ≥50% subgroup.
• The OS benefit was also consistent across subgroups defined by metastatic burden: HR=0.47 in patients with ≥3 metastatic sites and HR=0.69 in those with liver metastases.

Comparable subsequent anticancer therapy between the two arms

Proportions of patients in the two groups who subsequently received immunotherapy: 13.9% in the treatment group vs 19.2% in the control group; proportions receiving targeted therapy: 12.4% vs 17.3%; proportions receiving ADC therapy: 4.5% vs 5.6%; proportions participating in other clinical trials: 0.8% vs 2.3%.

Favorable safety profile comparable to tislelizumab plus chemotherapy

• Grade ≥3 treatment-related adverse events (TRAEs) occurred in 69.2% of patients in the ivonescimab arm and 58.9% in the control arm.
• Rates of adverse events leading to treatment discontinuation or death were similar between arms.

At the prespecified interim analysis for progression-free survival (PFS), ivonescimab plus chemotherapy had already demonstrated a clinically meaningful and statistically significant improvement in PFS compared with tislelizumab plus chemotherapy, with a median PFS of 11.1 months versus 6.9 months (HR=0.60 [95% CI: 0.46–0.78], P＜0.0001).

Professor Shun Lu, Principal Investigator of HARMONi-6, Director of the Lung Cancer Center at Shanghai Chest Hospital and Tenured Professor:

"HARMONi-6 is the first global Phase III study in lung cancer to show statistically significant improvements in both OS and PFS compared with PD-1 plus chemotherapy. It is also the first in sq-NSCLC to achieve dual OS and PFS success through a pre-specified hypothesis test. The results significantly reduced the risk of death and disease progression, with consistent benefits across all subgroups, while enabling patients to maintain better quality of life for longer.

These strong head-to-head data redefine the gold standard for first-line sq-NSCLC treatment and fill a major clinical gap for anti-angiogenic therapy in this setting. We look forward to ivonescimab delivering broader benefits to patients worldwide as a next-generation immuno-oncology therapy."

Dr. Yu Xia, Founder, Chairwoman, President and CEO of Akeso:

"Today, we are thrilled to announce that ivonescimab plus chemotherapy has successfully challenged PD-1 plus chemotherapy, achieving both clinically meaningful and statistically significant improvements in overall survival (OS) and progression-free survival (PFS). We extend our sincere gratitude to all investigators, clinical teams, and patients who participated in this study. Thanks to their efforts, Chinese patients with advanced sq-NSCLC are the first to benefit from this innovative, safe, and highly effective global therapy.

Prior to ivonescimab, no therapy had successfully challenged the dominance of PD-1-based regimens in a head-to-head Phase III trial. Ivonescimab has already demonstrated dual OS and PFS benefits in EGFR-mutant non-squamous NSCLC after TKI failure, becoming the first immunotherapy approved in this setting. It has also shown superior PFS versus pembrolizumab monotherapy in first-line PD-L1-positive NSCLC. These results have generated strong global anticipation for next-generation therapies. Since its launch, ivonescimab has been widely adopted by clinicians and patients.

PD-1 plus chemotherapy is currently the most broadly used first-line regimen in oncology. Following our previous success versus pembrolizumab monotherapy, the HARMONi-6 study now demonstrates for the first time that ivonescimab plus chemotherapy can achieve dual superiority in both OS and PFS over PD-1 plus chemotherapy. This landmark result solidifies ivonescimab's position as a next-generation cornerstone of cancer immunotherapy.

The success of HARMONi-6 gives us even greater confidence to leverage global resources, fully unlock ivonescimab's potential, reshape treatment paradigms, and deliver more effective and safer solutions to patients worldwide."

Ivonescimab is currently being evaluated in more than 30 clinical settings across a wide range of tumors, including 15 Phase III trials, seven of which are head-to-head studies versus PD-1/PD-L1 therapies. The positive results from HARMONi-6 further strengthen its differentiated clinical profile. In partnership with Summit Therapeutics, Akeso remains fully committed to advancing the global development of ivonescimab to maximize its therapeutic benefit for patients worldwide.

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 established a robust R&D innovation ecosystem centered on its 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. Supported by a global-standard GMP manufacturing infrastructure and a highly efficient, integrated commercialization model, the company has evolved into a globally competitive biopharmaceutical 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, 27 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.

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 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.

SOURCE Akeso, Inc.