HARMONi primary analysis reports 6.8 against 4.4 months PFS for ivonescimab plus chemotherapy after EGFR TKI progression

Median progression-free survival of 6.8 months against 4.4, at a hazard ratio of 0.52

Summit states in the release that the progression-free survival result was assessed by an independent radiographic review committee. The difference in medians is 2.4 months, and the hazard ratio of 0.52 has a 95% confidence interval running from 0.41 to 0.66, so the interval does not approach 1.

The setting is the reason a 2.4-month median matters more than the number alone suggests. Summit describes the population as patients whose disease has progressed after a third-generation EGFR tyrosine kinase inhibitor, and states in the same release that treatment options in that setting remain limited. The company’s own headline claim on the release is that this is the first immunotherapy-based regimen to show a statistically significant and clinically meaningful progression-free survival benefit in a global Phase III study in this population. That is Summit’s characterisation of its own result.

“Once a patient with EGFR-mutated lung cancer progresses after a third-generation EGFR TKI, there are limited treatment options for those patients and the survival may be limited.”Xiuning Le, MD, PhD, The University of Texas MD Anderson Cancer Center, lead author of the HARMONi manuscript

A double-blind trial at 114 centres across three continents

The manuscript is titled “Ivonescimab plus chemotherapy versus placebo plus chemotherapy in patients with advanced EGFR-mutated non-small cell lung cancer after EGFR-TKI progression (HARMONi): a randomised, double-blind, multi-centre phase 3 trial”, and Summit reports it as covering primary efficacy and safety results from a study run at 114 cancer centres and hospitals across Asia, Europe and North America.

The comparator is placebo plus platinum-doublet chemotherapy, so both arms received chemotherapy and the trial tests the addition of ivonescimab rather than ivonescimab on its own. The release names no enrolment figure and no randomisation ratio for HARMONi. Its only patient counts are for ivonescimab as a whole: over 4,000 treated in clinical studies globally, and over 70,000 including the commercial setting in China, as noted by Akeso.

An overall survival hazard ratio of 0.76 in western patients, from a June 2026 data cut

Overall survival is not part of this announcement’s primary analysis reporting. Summit refers back to an update it announced on 22 July 2026, based on a June 2026 data cut-off, in which ivonescimab plus chemotherapy continued to show what the company calls a positive overall survival trend, with a consistent efficacy and safety profile in Asian and western patients compared with chemotherapy alone. Western patients had an overall survival hazard ratio of 0.76, which Summit describes as consistent with the global study population.

A trend is not a met endpoint, and the company’s own definition in the release is that a positive study is one in which a prespecified primary endpoint achieves statistical significance. Further detail from that updated analysis is scheduled for presentation at the IASLC World Conference on Lung Cancer on 15 September 2026, in session OA14, abstract OA14.04.

The captured release carries no p value and no safety figures

The text of the announcement captured by the engine breaks off mid-sentence at the p value for the progression-free survival comparison, so that figure cannot be read from it. Nor does the captured text give any adverse event rate, any safety population size, or a median overall survival for either arm, although it states that the manuscript reports primary safety results alongside efficacy.

Summit has an application before the FDA for ivonescimab with platinum-doublet chemotherapy in this indication, with a Prescription Drug User Fee Act goal action date of 14 November 2026. Ivonescimab is a bispecific antibody targeting PD-1 and VEGF in one molecule, engineered by Akeso, and remains investigational in the United States.