New DLL3-Targeting Lung Cancer Drugs Show Promise
Preliminary trial data suggest these new therapies could offer future options for patients with small cell lung cancer.
Updated on Oct. 24, 2026 in Cancer
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New phase 1b clinical data presented at ESMO26 show promising responses for two investigational drugs targeting the DLL3 protein in small cell lung cancer. These findings highlight potential new therapy options for patients with this aggressive disease.
Why it matters
Small cell lung cancer remains a difficult-to-treat diagnosis, and these DLL3-targeting drugs offer researchers new ways to attack the cancer cells. This development could eventually change the standard of care by moving toward chemo-free treatment options.
Phase 1b trial results presented at ESMO26 evaluated the DLL3-targeting antibody-drug conjugate zocilurtatug pelitecan in combination regimens and the agent IDE849 in a 122-subject study. Findings indicated confirmed objective response rates of up to 92.3% and 60.8% respectively, though the results remain preliminary.
The players
Zai Lab
A biopharmaceutical company focused on developing therapies for oncology and autoimmune conditions.
Ideaya
A precision medicine company working on synthetic lethality and targeted oncology therapies.
Hengrui
A pharmaceutical manufacturer with a broad portfolio of treatments for oncology and internal medicine.
The details
These drugs are antibody-drug conjugates designed to seek out the DLL3 protein, which is expressed in up to 96% of small cell lung cancer and neuroendocrine carcinoma cases. By binding to this protein, the agents deliver a targeted therapy directly to the cancer cells to inhibit growth. Zai Lab tested its agent at a 1.6 mg/kg dose in combination with immunotherapy, while the IDE849 study evaluated efficacy in a Chinese patient population as a second-line treatment.
Timeline
October 2026: Zai Lab and Ideaya presented trial data at ESMO26.
2024: Ideaya licensed rights to IDE849 from Hengrui.
2025: Amgen's Imdelltra generated $627 million in sales.
Before the end of 2026: Zai Lab expects to begin an international phase 3 trial.
Health Landscape
These findings sit within a competitive field for DLL3-targeted cancer therapies, following the market entry of agents like Amgen's Imdelltra. The push toward international phase 3 registration trials marks a significant step in diversifying treatment options for neuroendocrine carcinomas.
These trial results represent early-stage research and are not yet available for clinical use, so patients should not change any current treatment plans. If you are managing small cell lung cancer, it is worth discussing the evolving landscape of targeted therapies with your oncologist.
The takeaway
Targeted therapies for DLL3 are becoming a major focus in lung cancer research, potentially offering more precise treatment options for the vast majority of patients. Patients or families affected by small cell lung cancer should stay updated on clinical trial opportunities through their primary care team.
What happens next
Zai Lab plans to initiate an international phase 3 trial for zocilurtatug pelitecan before the end of 2026.
Further reading
For more information on the current state of treatment, visit Cancer.
Source note: This article includes information reported by Pharmaphorum.
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