Akeso's ivonescimab beats tislelizumab in Phase III squamous NSCLC overall survival trial

Akeso (HKEX: 9926.HK) [reported](https://www.prnewswire.com/news-releases/harmoni-6-demonstrates-significant-overall-survival-benefit-hr0-66-ivonescimab-plus-chemotherapy-superior-to-pd-1-plus-chemotherapy-in-first-line-sq-nsclc-landmark-results-to-be-presented-at-asco-2026-plenary-session-302786433.html) on Saturday that [ivonescimab](https://app.allsci.com/drugs/ASC-DR-0000000024618-1.0-1772718717), its PD-1/VEGF bispecific antibody, cut the risk of death by 34% compared with a PD-1 inhibitor plus chemotherapy in first-line squamous NSCLC. The result marks the first time any therapy has beaten a PD-1-based regimen in a head-to-head Phase III overall survival test for the indication. The results were simultaneously published in *The Lancet* and selected for the ASCO 2026 plenary session, the first time a China-originated oncology drug has reached that platform in the society's 61-year history. The [HARMONi-6](https://app.allsci.com/clinical-trial/ASC-CT-0000000201552-1.0-1745776457) study enrolled 532 patients with advanced squamous NSCLC and randomized them to ivonescimab plus chemotherapy or BeiGene's Tevimbra (tislelizumab) plus chemotherapy. With a median follow-up of 21.36 months and a data cutoff of February 27, 2026, ivonescimab overall survival reached a median of 27.9 months versus 23.7 months in the tislelizumab arm (HR\=0.66; 95% CI: 0.50–0.87; P\=0.0017). The 24-month OS rate diverged meaningfully: 64.7% versus 48.6%. At a prespecified interim analysis, progression-free survival also favored ivonescimab, with a median of 11.1 months versus 6.9 months (HR\=0.60; 95% CI: 0.46–0.78; P \< 0.0001). The OS benefit was consistent across PD-L1 subgroups and in patients with higher metastatic burden, including those with liver metastases (HR\=0.69) and three or more metastatic sites (HR\=0.47). Grade ≥3 treatment-related adverse events occurred in 69.2% of patients in the ivonescimab arm versus 58.9% in the tislelizumab arm — a numerically higher rate, though rates of discontinuation and treatment-related death were described as similar between arms. Ivonescimab is designed to block both PD-1 and VEGF through a single bispecific molecule, with the rationale that simultaneous immunologic and anti-angiogenic activity may produce more durable tumor control than either pathway alone — particularly in squamous NSCLC, where anti-VEGF agents such as bevacizumab have historically been avoided due to bleeding risk. The HARMONi-6 trial results now provide OS-level evidence for that hypothesis in this histology. The result is particularly noteworthy since ivonescimab is being developed globally by Summit Therapeutics outside China. Positive OS data from HARMONi-6 may strengthen expectations for ongoing global Phase III studies and increase pressure on established PD-1 franchises led by Merck's Keytruda. The current standard of care in first-line squamous NSCLC is built around Merck's Keytruda (pembrolizumab) plus carboplatin and paclitaxel or nab-paclitaxel, which demonstrated a 36% reduction in the risk of death versus chemotherapy alone in KEYNOTE-407 (HR\=0.64). Cross-trial comparisons are limited by differences in patient populations, comparator arms, and follow-up duration, but the ivonescimab overall survival hazard ratio of 0.66 versus an active PD-1 comparator — rather than chemotherapy alone — carries a different evidentiary weight. Akeso has submitted a biologics license application to the FDA for ivonescimab in EGFR-mutant non-squamous NSCLC after TKI failure, with a [PDUFA date anticipated in November 2026](https://app.allsci.com/news/ASC-NR-0000002366877-1.0-1779381220?query=ivonescimab). As noted, the company is developing ivonescimab in partnership with Summit Therapeutics for global markets outside China. --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/ivonescimab-squamous-nsclc-akesos-beats)