Ideaya, Hengrui Pharma presented initial data from Phase 1 IDE849 trial

IDEAYA Biosciences (IDYA) and Hengrui Pharma presented initial data from Hengrui’s Phase 1 clinical trial of IDE849, a potential first-in-class delta-like ligand 3-targeting Topoisomerase-1 antibody drug conjugate, in an oral presentation today at the IASLC 2025 World Conference on Lung Cancer in Barcelona, Spain. The presentation included data from a total of 100 patients who received IDE849 at doses between 0.8 mg/kg to 4.2 mg/kg with a once every 3-week dosing interval. Data in the presentation were as of a cut-off date of June 20, 2025, and included 87 patients with small-cell lung cancer and 13 patients with other neuroendocrine carcinomas. All patients had progressed after front-line therapy, with 33% having progressed after two prior lines and 15% after three or more prior lines of therapy. Of the 87 SCLC patients enrolled, 72.4% had received prior immunotherapy. A total of 71 patients with refractory SCLC were evaluated for initial efficacy at doses of 2.4 mg/kg, 3.0 mg/kg and 3.5 mg/kg in the expansion phase of the trial. Patients in the 4.2 mg/kg cohort of the dose escalation phase were also included in the analysis. All efficacy-evaluable patients had received at least one post-baseline tumor assessment per RECIST v1.1.