By Fineline Cube 
Summit Therapeutics (NASDAQ: SMMT) disclosed longer‑term progression‑free survival (PFS) data from its HARMONi trial of the bispecific antibody ivonescimab at the 2025 World Conference on Lung Cancer. The new figures show a 33 % PFS benefit for European and North American patients, compared with 45 % in Chinese patients, and a 43 % overall risk‑reduction across the full study cohort.
Key Findings
| Region | PFS Benefit | Risk‑Reduction |
|---|---|---|
| Europe & North America | 33 % | – |
| China | 45 % | – |
| Entire Population | – | 43 % |
- Long‑term follow‑up: 257 PFS events in the Chinese subgroup vs. 18 events in the ex‑China group during the initial global Phase 3 analysis.
- Phase 3 (May 2025): 48 % reduction in risk of disease progression or death when ivonescimab was combined with chemotherapy.
- Subgroup consistency: Despite regional differences, the study authors noted that the PFS benefit remained statistically consistent across all predefined subgroups.
About Ivonescimab
- First‑in‑class bispecific antibody that simultaneously blocks PD‑1 and VEGF pathways, delivering both immune‑mediated and anti‑angiogenic effects.
- Developed by China‑based Akeso Inc. (HKEX: 9926).
- Exclusive U.S., Canada, Europe, and Japan rights granted to Summit in December 2022, with a potential value of $5 billion.
- July 2025: Reports of AstraZeneca negotiating a licensing deal with Summit, potentially valued at $15 billion.
Strategic Implications
- Commercial pipeline: The HARMONi data support Summit’s expansion plans in key markets, particularly in the U.S. and Europe.
- Partnership prospects: The potential AstraZeneca deal could accelerate global commercialization and provide significant capital for further development.
- Market differentiation: Ivonescimab’s dual‑target mechanism positions it uniquely against competitors that focus on single‑pathway inhibition.
Bottom Line
Summit Therapeutics’ latest HARMONi results underscore the global potential of ivonescimab, while highlighting regional efficacy variations. The company’s strategic partnership with Akeso and possible collaboration with AstraZeneca could position it as a leading player in the next generation of immuno‑anti‑angiogenic therapies for lung cancer.-Fineline Info & Tech