A bispecific antibody developed by the Chinese biotech Akeso reduced the risk of death by 34% in squamous non-small-cell lung cancer, presenting at the American Society of Clinical Oncology's plenary session on May 31 — the first time a China-originated investigational drug has been selected for the conference's most prestigious slot in its 61-year history. [1]

The HARMONi-6 Phase III trial enrolled 532 patients and compared ivonescimab plus chemotherapy against tislelizumab — a PD-1 inhibitor comparable to Merck's Keytruda — plus chemotherapy. Ivonescimab is a first-in-class bispecific antibody that simultaneously targets PD-1 and VEGF, combining immune checkpoint inhibition with anti-angiogenic activity. The hazard ratio was 0.66, with median overall survival of 27 months for the ivonescimab arm versus approximately 20 months for the comparator. The results were simultaneously published in The Lancet. [2]

"I'm mindful of the fact that this trial was done exclusively in China," Dr. Suresh Ramalingam of Emory University noted during the plenary session — raising the generalizability question that will shape U.S. regulatory review. [1]

The plenary designation is the signal. ASCO selects abstracts for plenary presentation based on clinical significance, methodological rigor, and the potential to change practice. A China-origin drug beating an established PD-1 inhibitor in a head-to-head Phase III trial is the kind of result that earns the slot. The question is whether FDA will accept China-only data for accelerated approval or require a global trial.

The FDA accepted a biologics license application for ivonescimab in January 2026 for pretreated EGFR-mutated NSCLC. A global Phase III trial is ongoing. The HARMONi-6 data adds squamous NSCLC to the clinical profile and strengthens the case for broader regulatory consideration. [2]

Merck's Keytruda franchise — the world's best-selling drug — faces a bispecific that targets both PD-1 and VEGF in a single molecule. The combination of checkpoint inhibition and anti-angiogenesis in one antibody is a design advantage that monotherapy PD-1 inhibitors cannot match. If Summit Therapeutics, the U.S. commercialization partner, can execute on the regulatory pathway, the competitive landscape for lung cancer immunotherapy shifts.

The paper's lost-science thread tracks clinical evidence that requires operational translation. This study is that evidence: a drug that works, from a country whose biotech sector is now producing first-in-class therapies that outperform Western standards of care, presented at the venue where Western standards of care are defined.

-- KENJI NAKAMURA, Tokyo