Summit Therapeutics (US:SMMT) Businesswire·2025-09-07 07:30Core Insights - The Phase III HARMONi trial data for ivonescimab plus chemotherapy shows an improving overall survival (OS) trend with a nominal p-value of 0.0332 compared to chemotherapy alone, particularly in North American patients with an OS hazard ratio (HR) of 0.70 [1][4][6] Group 1: Trial Overview - HARMONi trial evaluated ivonescimab plus platinum-doublet chemotherapy against placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) who progressed after third-generation EGFR TKI treatment [2][18] - The trial's primary endpoints were progression-free survival (PFS) and overall survival (OS), with previous PD-1 monoclonal antibodies failing to show benefits in similar settings [2] Group 2: Efficacy Results - In the primary analysis, ivonescimab plus chemotherapy showed a median OS of 16.8 months versus 14.0 months for placebo plus chemotherapy, with a hazard ratio of 0.79 (95% CI: 0.62 – 1.01; p=0.057) [4][6] - Longer-term follow-up analysis indicated a median OS of 17.0 months for ivonescimab compared to 14.0 months for placebo in Western patients, with an improved hazard ratio of 0.84 [6][7] - The overall response rate was higher in the ivonescimab arm at 45% compared to 34% in the placebo arm, with a median duration of response of 7.6 months versus 4.2 months [10] Group 3: Safety Profile - Ivonescimab plus chemotherapy demonstrated a manageable safety profile, with 7.3% of patients discontinuing due to treatment-related adverse events (TRAEs) compared to 5.0% in the placebo group [12][13] - The most common TRAEs included anemia and decreases in white blood cell counts, with less than 1% experiencing Grade 3 or higher hemorrhage events [12][13] Group 4: Future Developments - Summit Therapeutics plans to host a conference call on September 8, 2025, to discuss the ivonescimab data presented at the WCLC 2025 [14][30] - The company is engaged in multiple Phase III clinical trials for ivonescimab, including HARMONi-2 and HARMONi-6, which are expected to further evaluate its efficacy [19][20]