80.0% (8/10) ORR and 70.0% (7/10) confirmed ORR in 2L SCLC; a 73.7% (14/19) ORR and 57.9% (11/19) confirmed ORR (1 pending confirmation) were observed across all lines of SCLC at the 2.4 mg/kg expansion dose of IDE849
77.1% (27/35) ORR and 60.0% (21/35) confirmed ORR (4 pending confirmation) in 2L SCLC; a 73.2% (52/71) ORR and 47.9% (34/71) confirmed ORR (10 pending confirmation) were observed across all lines of SCLC at all expansion doses of IDE849
In patients with baseline brain metastases, a 83.3% (5/6) confirmed ORR at the 2.4 mg/kg dose was observed; across all doses ≥2.4 mg/kg (n=18), a 66.7% (12/18) confirmed ORR (1 pending confirmation) was observed
14.1% (10/71) of patients across all doses >2.4 mg/kg are still pending confirmation, as well as multiple patients that have had limited follow-up (e.g. one post-baseline scan) highlighting the study has not yet achieved a fully mature confirmed ORR%
6.7 month median progression free survival (PFS) across all lines of SCLC across all dose levels (≥2.4 mg/kg); mPFS not reached in 2L SCLC patients
Manageable safety profile observed across multiple expansion cohorts, including the 2.4 mg/kg, 3.0 mg/kg, and 3.5 mg/kg dose levels with a once every 3-week dosing interval
SHANGHAI and SOUTH SAN FRANCISCO, Calif., Sept. 7, 2025 /PRNewswire/ — IDEAYA Biosciences, Inc. (Nasdaq: IDYA), a leading precision medicine oncology company, and Hengrui Pharma, a 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 today 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.
(PRNewsfoto/IDEAYA Biosciences, Inc.)
“We believe the ORR, median PFS, and overall safety data presented at WCLC 2025 in over 70 efficacy evaluable SCLC patients provides a potential best-in-class DLL3 TOP1 ADC profile,” said Yujiro S. Hata, President and Chief Executive Officer, IDEAYA Biosciences. “We look forward to advancing the global clinical development of IDE849 in SCLC, NETs, and additional DLL3 upregulated solid tumors, as both a potential first-in-class and best-in-class DLL3 TOP1 ADC to address areas of high unmet medical need in cancer.”
Data in the presentation were as of a cut-off date of June 20, 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% having progressed after two prior lines and 15% after three or more prior lines of therapy. Of the 87 SCLC patients enrolled, 72.4% (63/87) had received prior immunotherapy. A total of 71 patients with refractory SCLC (2L+) were evaluated for initial efficacy at doses of 2.4 mg/kg (n=19), 3.0 mg/kg (n=18) and 3.5 mg/kg (n=31) in the expansion phase of the trial. Patients in the 4.2 mg/kg cohort (n=3) 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.
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