California-based precision medicine oncology company IDEAYA Biosciences Inc (Nasdaq: IDYA) and Hengrui Pharma, a China-based global pharmaceutical company focused on scientific and technological innovation, presented initial data from Hengrui's Phase 1 clinical trial of IDE849 (SHR-4849), a potential first-in-class delta-like ligand 3 (DLL3)-targeting Topoisomerase-1 (TOP1) antibody drug conjugate (ADC), in an oral presentation on Sunday at the IASLC 2025 World Conference on Lung Cancer (WCLC) 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 20 June 2025, and included 87 patients with small-cell lung cancer (SCLC) and 13 patients with other neuroendocrine carcinomas (NEC). All patients had progressed after front-line therapy, with 33 percent having progressed after two prior lines and 15 percent after three or more prior lines of therapy.

IDEAYA will review the data that was presented by Hengrui at its 10-Year Anniversary R&D Day on 8 September 2025 in New York.