A bispecific antibody developed in China has done something no drug had managed before: beaten the established immunotherapy standard for a common form of lung cancer in a head-to-head trial. Akeso announced on May 31 that ivonescimab, paired with chemotherapy, produced a statistically significant and clinically meaningful improvement in overall survival as a first-line treatment for advanced squamous non-small cell lung cancer in the Phase III HARMONi-6 study. The result, presented at the American Society of Clinical Oncology’s annual meeting in Chicago and published simultaneously in The Lancet, lands as both a clinical milestone and a marker of how far Chinese biotech has come.
What The Trial Showed
The headline figure is a sharp one. In the intent-to-treat population, ivonescimab plus chemotherapy reduced the risk of death by 34% versus tislelizumab plus chemotherapy, with a hazard ratio of 0.66 and a p-value of 0.0017. Patients on ivonescimab lived a median of about 28 months after enrollment, compared with 24 months for the control group. The study enrolled 532 patients, roughly 63% of whom had centrally located squamous tumors, a notably difficult-to-treat group.
That four-month survival gain carries weight in a disease where progress has been incremental. Oncologists described the extension as substantial given how limited options are for this patient population, and industry watchers who typically regard a 30% improvement as a major win noted the 34% figure exceeded expectations.
Why The Drug’s Design Matters
Ivonescimab’s appeal lies in its mechanism. The bispecific antibody targets both PD-1, the pathway behind Merck’s best-selling Keytruda, and VEGF, the target of Roche’s Avastin, combining two of oncology’s most commercially important approaches into a single molecule. The PD-1/VEGF class has become one of the most closely watched and debated frontiers in cancer treatment.
The squamous setting is where that design becomes consequential. Squamous lung tumors, most often linked to smoking, tend to develop near major blood vessels, and blocking VEGF can interfere with those vessels’ ability to repair themselves, raising the risk of dangerous bleeding. That hazard had long limited anti-angiogenic therapy in these patients. HARMONi-6 suggests the bispecific approach can manage it: severe hemorrhages of grade 3 or above occurred in 2.6% of the ivonescimab group versus 0.8% in the comparison arm. Bleeding of any severity, however, occurred in nearly a quarter of ivonescimab patients, roughly double the control group, a signal clinicians will watch as the drug moves toward wider use.
A Test For Chinese Biotech On A Global Stage
The trial’s significance extends beyond the clinic. The overall survival data came from an interim analysis of a trial conducted entirely in China, and it marked the first time a China-only data set was selected for presentation at ASCO’s prestigious plenary session. For an industry that has spent years trying to shed a reputation for derivative work, that placement is a statement.
It also complicates how the result should be read. One oncologist cautioned that this is a first randomized controlled trial in a geographically limited Chinese population, making it hard to know how the findings apply elsewhere. That uncertainty is precisely why the cross-border structure matters. Ivonescimab was developed by Akeso and is already available in China, while Summit Therapeutics holds development and commercialization rights in the United States. The licensing arrangement has become a template for how Chinese-originated drugs reach Western markets, and ivonescimab is now its most prominent test case.
The Regulatory And Commercial Road Ahead
Summit is already pursuing US approval on a separate front. The company has submitted a biologic license application for ivonescimab in patients with EGFR-mutated non-squamous NSCLC after TKI therapy, with a regulatory decision date of November 14, 2026, based on the HARMONi trial. A larger global study, HARMONi-3, is testing the drug against the chemotherapy-plus-Keytruda regimen that anchors treatment for many lung tumors — the trial likeliest to determine whether the China results translate internationally.
For the broader market, the implications are competitive. Beating a PD-1 inhibitor head-to-head, rather than merely matching it, positions the PD-1/VEGF class as a potential successor to the checkpoint inhibitors that have dominated oncology for a decade. Whether ivonescimab realizes that potential depends on confirmatory data in more diverse populations and on how regulators weigh a strong but single-region survival signal.
What is clear is that a drug conceived in Shenzhen has redrawn expectations for first-line squamous lung-cancer treatment, and that the next chapter will be written in trials spanning far beyond China.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. It summarizes clinical-trial findings and should not be used to make treatment decisions. Ivonescimab is not approved for squamous NSCLC in the United States, and clinical-trial results may differ from real-world outcomes. Patients should consult a qualified healthcare professional regarding any medical condition or treatment option.
