Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) announced a clinical trial collaboration with Amgen Inc. (NASDAQ: AMGN) to evaluate a combination therapy for extensive-stage small cell lung cancer patients.

Under the agreement, Amgen will sponsor and lead a global Phase 1b study combining Zai Lab's investigational drug zocilurtatug pelitecan with Amgen's approved therapy IMDELLTRA. The study will assess safety and efficacy in patients with extensive-stage small cell lung cancer.

Zai Lab will retain full ownership of zocilurtatug pelitecan, a delta-like ligand 3-targeting antibody-drug conjugate, and will supply the drug for the study. The company presented data from earlier trials showing response rates in heavily pretreated small cell lung cancer patients.

Zocilurtatug pelitecan uses TMALIN technology platform and comprises a humanized anti-DLL3 monoclonal antibody linked to a camptothecin derivative payload. The drug has received FDA Orphan Drug Designation and Fast Track Designation for small cell lung cancer treatment.

IMDELLTRA received FDA approval for treating adult patients with extensive-stage small cell lung cancer following disease progression on platinum-based chemotherapy. The drug is currently marketed in the United States.

Small cell lung cancer accounts for approximately 15% of the 2.5 million lung cancer cases diagnosed globally each year. Two-thirds of patients are diagnosed at extensive stage, with median survival of approximately 12 months following initial therapy and a 5-10% five-year survival rate.

The collaboration agreement information was disclosed in a company press release.