Zai Lab Announces Global Clinical Trial Collaboration and Supply Agreement to Evaluate Novel DLL3 ADC, Zocilurtatug Pelitecan, in Combination with a Bispecific T-Cell Engager Therapy

Key Takeaways

• Amgen sponsors global Phase 1b zoci + IMDELLTRA trial.
• Zoci retains full ownership, supplied by Zai Lab.
• Dual DLL3 targeting aims to improve SCLC response rates.
• Zoci has orphan and fast track FDA designations.
• Combination may address brain metastases and resistance.

Summary

Zai Lab and Amgen have entered a global collaboration to test Zai Lab’s DLL3‑targeting antibody‑drug conjugate, zocilurtatug pelitecan (zoci), together with Amgen’s FDA‑approved bispecific T‑cell engager IMDELLTRA® in extensive‑stage small cell lung cancer (ES‑SCLC). Amgen will sponsor and lead a Phase 1b study, while Zai Lab retains full ownership of zoci and will supply the drug. Early data show zoci delivers high response rates and intracranial activity in heavily pre‑treated patients. The partnership aims to combine cytotoxic delivery with immune activation to deepen and broaden treatment responses.

Pulse Analysis

Small cell lung cancer remains one of the deadliest solid tumors, accounting for roughly 15% of the 2.5 million lung‑cancer diagnoses worldwide each year. Patients diagnosed at the extensive stage face median survivals of about 12 months and five‑year survival rates under 10%. The recent FDA approval of Amgen’s IMDELLTRA®, a DLL3‑directed bispecific T‑cell engager, marked the first immunotherapy to demonstrate an overall survival benefit in this setting, yet resistance and brain metastases continue to limit outcomes. By pairing IMDELLTRA® with a second DLL3‑directed modality, the industry seeks to overcome these gaps.

Zocilurtatug pelitecan (zoci) is a next‑generation ADC that couples a humanized anti‑DLL3 antibody with a camptothecin‑derived topoisomerase I inhibitor via Zai Lab’s TMALIN® platform. This technology is designed to release its payload preferentially within the tumor microenvironment, reducing off‑target toxicity that plagued earlier ADCs. Phase 1/2 data presented at major oncology meetings revealed robust systemic and intracranial responses in heavily pre‑treated SCLC patients, earning the drug orphan and Fast Track designations from the FDA. The ADC’s tolerable safety profile positions it as a viable backbone for combination regimens, potentially replacing or reducing chemotherapy intensity.

The Amgen‑Zai Lab alliance leverages complementary expertise: Amgen’s global trial infrastructure and commercial muscle with IMDELLTRA®, and Zai Lab’s innovative ADC pipeline. By retaining ownership of zoci, Zai Lab safeguards future revenue streams while benefiting from Amgen’s sponsorship and broader patient access. If the Phase 1b study confirms synergistic efficacy, the duo could set a new standard of care for ES‑SCLC, opening avenues for similar dual‑targeting strategies in other neuroendocrine cancers. Investors and analysts will watch enrollment metrics and early safety signals closely, as success could translate into significant market share in a $5 billion‑plus lung‑cancer therapeutic space.