Ivonescimab plus chemotherapy versus placebo plus chemotherapy in patients with advanced EGFR-mutated non-small-cell lung cancer after disease progression on EGFR tyrosine kinase inhibitor therapy (HARMONi): a multicentre, randomised, double-blind, phase 3 trial.

Ivonescimab has shown clinical efficacy in non-small-cell lung cancer (NSCLC). We aimed to assess the efficacy and safety of ivonescimab plus chemotherapy versus placebo plus chemotherapy in patients with advanced EGFR-mutated NSCLC whose disease progressed after third-generation EGFR tyrosine kinase inhibitor (TKI) therapy. HARMONi is a randomised, placebo-controlled, double-blind, phase 3 trial done at 114 cancer centres and hospitals across Asia, Europe, and North America. Eligible patients were aged at least 18 years (upper limit: 75 years in Asia) with stage IIIB/IIIC or IV non-squamous EGFR-mutated NSCLC, disease progression after treatment with a third-generation EGFR-TKI, and an Eastern Cooperative Oncology Group performance status score of 0 or 1. Patients were randomly assigned (1:1) via a centralised interactive voice response system or interactive web response system to receive ivonescimab (20 mg/kg) or placebo plus pemetrexed (500 mg/m2) and carboplatin (target area under the curve 5 mg/mL per min) intravenously every 3 weeks. Randomisation was stratified by brain metastases status at enrolment and geographical region. The primary endpoints were progression-free survival by blinded independent radiology review committee and overall survival in the intention-to-treat population. Safety was assessed in patients who received at least one dose of trial treatment. This study is registered with ClinicalTrials.gov (NCT06396065), has completed enrolment, and is ongoing for treatment and follow-up. From Jan 25, 2022, to Oct 1, 2024, 660 individuals were screened for eligibility; of these, 438 were enrolled and randomly assigned to receive ivonescimab plus chemotherapy or placebo plus chemotherapy (219 per group). Of enrolled patients, 257 (59%) were female and 181 (41%) were male; 306 (70%) reported race as Asian, and 105 (24%) as White. At a median follow-up of 22·3 months (95% CI 21·5-23·0), 275 progression or death events had occurred in 345 patients (129 events among 172 patients in the ivonescimab plus chemotherapy group and 146 events among 173 patients in the placebo plus chemotherapy group). Median progression-free survival was 6·8 months (95% CI 5·7-7·1) in the ivonescimab plus chemotherapy group versus 4·4 months (4·1-5·5) in the placebo plus chemotherapy group (hazard ratio [HR] 0·52; 95% CI 0·41-0·66; p<0·0001). At a median follow-up of 29·7 months (95% CI 27·7-31·0), 262 deaths occurred in 438 patients (122 in the ivonescimab plus chemotherapy group and 140 in the placebo plus chemotherapy group). Median overall survival was 16·8 months (14·3-19·0) in the ivonescimab plus chemotherapy group versus 14·0 months (12·8-15·7) in the placebo plus chemotherapy group (HR 0·79; 0·62-1·01). The most common grade 3-4 treatment-related adverse events in the ivonescimab plus chemotherapy versus the placebo plus chemotherapy group were decreased neutrophil count (42 [19%] of 218 vs 36 [17%] of 218), decreased white blood cell count (28 [13%] vs 24 [11%]), decreased platelet count (27 [12%] vs 14 [6%]), and anaemia (22 [10%] vs 27 [12%]). Serious treatment-related adverse events occurred in 61 (28%) patients in the ivonescimab plus chemotherapy group and 33 (15%) patients in the placebo plus chemotherapy group. Treatment-related adverse events led to death in four patients (disease progression, multiple organ dysfunction syndrome, and hepatic failure, each in one patient; gastrointestinal haemorrhage and pulmonary embolism in one patient) in the ivonescimab plus chemotherapy group and five patients (pneumonitis, myocardial infarction, cerebrovascular accident, cognitive disorder, and embolic stroke, each in one patient) in the placebo plus chemotherapy group. Ivonescimab plus chemotherapy showed a clinically meaningful and statistically significant progression-free survival benefit in patients with EGFR-mutated NSCLC after progression on EGFR-TKI therapy. The clinical benefit and lack of new safety signals of ivonescimab with chemotherapy support the potential for the combination as a new treatment option in this patient population. Summit Therapeutics.