Akeso, Inc. (HKEX: 9926.HK) announced on September 2 that a pre-specified interim analysis of overall survival in its Phase III HARMONi-2 trial met the study’s key secondary endpoint, with what the company describes as a statistically significant and clinically meaningful improvement for ivonescimab over pembrolizumab. Notably, the release does not disclose the actual hazard ratio, median survival figures, or event counts behind that claim; Akeso says detailed data will be presented at a future international medical conference and published in a peer-reviewed journal. This is a recurring pattern in how Akeso has announced several ivonescimab trial results in 2026: confirming that a trial won without yet disclosing by how much.
What HARMONi-2 Is
HARMONi-2 (AK112-303) is a randomized, double-blind, multicenter Phase III trial conducted entirely in China, comparing ivonescimab alone against pembrolizumab alone as a first-line treatment for patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose tumors express PD-L1. Pembrolizumab, sold as Keytruda by Merck (NYSE: MRK), is one of the best-selling cancer drugs in the world and the existing standard-of-care comparator this trial was designed to beat. The trial’s primary endpoint, progression-free survival, was already met back in May 2024, with a median of 11.14 months for ivonescimab versus 5.82 months for pembrolizumab, real, specific figures Akeso did disclose at the time. That result supported an NMPA approval for ivonescimab monotherapy in this patient population in 2025.
A Second Look at Overall Survival
This is not the first overall survival readout from HARMONi-2, either. In April 2025, as part of China’s regulatory review of a related application, Akeso disclosed an earlier interim OS analysis showing a hazard ratio of 0.777, at 39% data maturity, which the company described then as a clinically meaningful positive trend rather than a formally confirmed win. Today’s announcement appears to reflect a more mature, later analysis of the same overall survival endpoint that the company is now characterizing as having formally met the threshold for statistical and clinical significance, though because no updated hazard ratio was disclosed in this release, it is not possible to say precisely how the effect size in this newer analysis compares to the 0.777 figure from April 2025.
How Ivonescimab Works
Ivonescimab is a bispecific antibody, meaning it is engineered to bind two different targets at once, in this case PD-1, the same immune checkpoint pembrolizumab blocks, and VEGF, a protein that helps tumors grow new blood vessels. The idea behind combining both mechanisms in one molecule is that blocking tumor blood vessel growth alongside reactivating the immune system’s ability to attack cancer cells could produce a stronger effect than blocking either pathway alone, which pembrolizumab, a PD-1-only antibody, does not attempt to do.
Part of a Broader Pattern
Akeso frames this HARMONi-2 result as part of a broader pattern: company chair and CEO Yu Xia’s quote in the release describes it as the fourth Phase III study of an ivonescimab-based regimen to demonstrate a significant overall survival benefit. Earlier in 2026, Akeso announced that a separate trial, HARMONi-6, showed ivonescimab plus chemotherapy improving overall survival with a disclosed hazard ratio of 0.66 versus a PD-1 inhibitor plus chemotherapy in squamous NSCLC, data selected for a Plenary Session at the 2026 ASCO Annual Meeting. Another trial, HARMONi-GI1, in biliary tract cancer, met its primary OS endpoint in August 2026, though similarly without disclosing a hazard ratio in that release either. Taken together, these announcements show Akeso building a wider body of positive Phase III data across multiple cancer types, even though the exact magnitude of many of those individual results remains undisclosed pending conference presentations.
Not to Be Confused With Summit’s Global HARMONi Trial
It is worth distinguishing HARMONi-2 from a separate, similarly named trial: the global HARMONi study (not HARMONi-2), which tests ivonescimab plus chemotherapy in EGFR-mutated NSCLC and is run by Summit Therapeutics Inc. (Nasdaq: SMMT), Akeso’s ex-China development partner, currently under FDA review with a target decision date of November 14, 2026. HARMONi-2 is a China-only, Akeso-sponsored trial testing ivonescimab as a monotherapy rather than in combination with chemotherapy, and today’s announcement does not directly involve Summit or the FDA review process, even though both trials share the broader ivonescimab development program and the HARMONi naming convention.
What’s Next
No pricing, revenue, or updated regulatory timeline specific to this OS result were disclosed in Akeso’s release, and none are estimated here. This article covers a clinical trial announcement with limited disclosed data and is not investment or medical advice; patients should consult a qualified healthcare professional regarding treatment options.
Sources
Akeso, Inc.: Ivonescimab Meets Overall Survival Key Secondary Endpoint in Interim Analysis of Phase III HARMONi-2 Study, Demonstrating Statistically Significant and Clinically Meaningful Benefit Versus Pembrolizumab in First-Line PD-L1-Positive NSCLC, PRNewswire, September 2, 2026.
Summit Therapeutics Inc.: Interim Overall Survival Analysis Requested from Chinese Health Authorities Shows a Clinically Meaningful, Positive Trend Favoring Ivonescimab Compared to Pembrolizumab in PD-L1 Positive Advanced NSCLC from HARMONi-2 Study Conducted by Akeso in China, April 25, 2025, cited for the earlier April 2025 interim OS analysis and hazard ratio.
Akeso, Inc.: HARMONi-6 Demonstrates Significant Overall Survival Benefit (HR=0.66): Ivonescimab Plus Chemotherapy Superior to PD-1 Plus Chemotherapy in First-Line sq-NSCLC, cited for comparison with a separate ivonescimab trial that did disclose a hazard ratio.
Editorial Disclosure
This article is based on a press release issued by Akeso, Inc. on September 2, 2026, distributed via PRNewswire, with additional context on prior HARMONi-2 and related ivonescimab trial disclosures drawn from Akeso’s and Summit Therapeutics’ own prior announcements, cited above. Akeso trades on the Hong Kong Stock Exchange under the ticker 9926.HK; Summit Therapeutics, a separate company involved in a different global ivonescimab trial discussed for context, trades on the Nasdaq under the ticker SMMT. BioTech Stocks Daily was not compensated for this coverage. The specific hazard ratio and other quantitative results behind this announcement’s overall survival claim were not disclosed by Akeso and are not estimated in this article. This article is for informational and educational purposes only, does not constitute investment advice, and is not medical advice. Consult a qualified healthcare professional for medical guidance. See our full DISCLAIMER.
