DLL3-Targeting Cancer Drugs Show Strong Results
Zai Lab and Ideaya report positive trial data for new small cell lung cancer therapies at ESMO26.
Updated on Oct. 24, 2026 in Cancer
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Zai Lab and Ideaya presented phase 1b trial results for novel DLL3-targeting cancer drugs during the ESMO26 conference. The therapies demonstrated high objective response rates in patients with extensive-stage small cell lung cancer.
Why it matters
Targeting the DLL3 protein offers a potential pathway to more effective, chemo-free treatment options for aggressive lung and neuroendocrine cancers. These results signal a major competitive advancement in the pursuit of specialized oncology therapies.
Zocilurtatug pelitecan combined with Tecentriq achieved an 81.8% confirmed objective response rate, rising to 92.3% with the addition of carboplatin. The DLL3-targeting ADC IDE849 showed a 60.8% confirmed response rate and 17.4-month median survival.
The players
Zai Lab
This pharmaceutical company is focused on developing oncology and autoimmune disease treatments for global markets.
Ideaya Biosciences
This precision medicine oncology company is based in South San Francisco and develops targeted therapeutics.
Hengrui
Headquartered in Shanghai, this biopharmaceutical company specializes in the development of cancer and surgical medications.
Amgen
This multinational biotechnology firm produces a range of human therapeutics, including the DLL3-targeting treatment Imdelltra.
The details
Zai Lab tested zocilurtatug pelitecan at a 1.6 mg/kg dose, while the 122-subject IDE849 study was conducted in China. DLL3 protein is found in up to 96% of small cell lung cancer and neuroendocrine carcinoma cases, making it a critical target for these new agents.
Timeline
In 2024, Ideaya licensed the rights to IDE849 from Hengrui.
In 2025, Amgen's drug Imdelltra generated $627 million in sales.
On October 24, 2026, Zai and Ideaya presented data at ESMO26.
Before the end of 2026, Zai Lab plans to start an international phase 3 trial.
Health Landscape
These new drug candidates directly challenge the market dominance of Amgen's Imdelltra, which established a new benchmark for DLL3-targeting therapies in 2025. This rapid development illustrates the intense shift toward precision oncology in the treatment of small cell lung cancer.
These developments signal the potential for future treatment options that could reduce or eliminate the need for traditional chemotherapy in lung cancer care. Patients may eventually gain access to more targeted, effective therapies that specifically address the DLL3 protein found in most of these tumor cases.
The takeaway
Targeting the DLL3 protein is rapidly becoming a cornerstone of small cell lung cancer research. Patients and providers should watch for upcoming phase 3 trial results to see if these high response rates hold up in larger, international populations.
What happens next
Zai Lab plans to initiate an international phase 3 clinical trial for zocilurtatug pelitecan before the end of 2026.
Further reading
Learn more about advancements in Cancer treatments and emerging clinical research.
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