Zai Lab Limited announced that updated data from its global Phase 1 clinical trial evaluating zocilurtatug pelitecan (formerly ZL-1310) has been selected for an oral presentation at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics, taking place October 22-26, 2025, in Boston, Massachusetts. The presentation will feature new data highlighting the potential of this Delta-like ligand (DLL3)-targeted antibody-drug conjugate (ADC) as a promising next-generation therapy for patients with extensive-stage small cell lung cancer (ES-SCLC).
Novel ADC Technology Platform Addresses Aggressive Cancer
Zocilurtatug pelitecan represents a potential first- and best-in-class DLL3-targeted ADC being developed specifically for ES-SCLC patients. The compound comprises a humanized anti-DLL3 monoclonal antibody connected via a cleavable linker to a novel camptothecin derivative, which functions as a topoisomerase 1 inhibitor payload. The drug was designed using a novel ADC technology platform called TMALIN®, which leverages the tumor microenvironment to overcome challenges associated with first-generation ADC therapies.
DLL3 is an antigen overexpressed in many neuroendocrine tumors, including SCLC, and is often associated with poor clinical outcomes. This targeted approach aims to deliver cytotoxic therapy directly to cancer cells while minimizing systemic toxicity.
Addressing Critical Unmet Medical Need
Small cell lung cancer represents one of the most aggressive and lethal solid tumors, accounting for approximately 15% of the 2.5 million patients diagnosed with lung cancer worldwide each year. The disease burden is particularly severe, with two-thirds of all SCLC patients diagnosed at extensive stage, when treatment options are limited and prognosis remains poor.
"The critical need for expanded treatment options for patients with small cell lung cancer propels our strategy to advance zoci as a novel therapeutic option as quickly as possible," said Rafael G. Amado, M.D., President, Head of Global Research and Development, Zai Lab.
Phase 1 Trial Design and Development Timeline
The ongoing Phase 1 study (NCT06179069) is evaluating the safety and antitumor activity of zocilurtatug pelitecan at various doses in patients who have progressed after at least one prior platinum-based chemotherapy regimen. The study is being conducted across multiple global sites and will provide additional follow-up data from patients in the ongoing trial.
Zai Lab remains on track to initiate a Phase 3 registrational study in previously treated SCLC by year-end, demonstrating an accelerated development timeline for this novel therapeutic approach. The company's aggressive development strategy reflects the urgent need for new treatment options in this patient population.
Regulatory Recognition and Future Prospects
Zocilurtatug pelitecan received Orphan Drug Designation from the U.S. Food and Drug Administration in January 2025, recognizing its potential to treat patients with SCLC. This designation provides various development incentives and reflects the FDA's acknowledgment of the significant unmet medical need in this indication.
The oral presentation will be delivered by Grace K. Dy, M.D., from Roswell Park Comprehensive Cancer Center, Buffalo, NY, during the Plenary Session on Antibody Drug Conjugates on Friday, October 24, 2025. Zai Lab will also host an investor conference call and webcast on the same day to discuss the updated data and outline next steps in clinical development.
