December 8, 2025 — Leads & Copy —
Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) has announced the dosing of the first participant in a global Phase 1/1b clinical trial evaluating ZL-1503, a potential first-in-class IL-13/IL-31R bispecific antibody intended for the treatment of atopic dermatitis (AD).
ZL-1503, identified and advanced by Zai Lab’s discovery team, targets both IL-13 and IL-31 pathways, and features an extended serum half-life. The dual targeting is designed to offer faster action and better efficacy, according to the company.
Preclinical studies have demonstrated ZL-1503’s ability to simultaneously suppress inflammatory and itch-causing pathways associated with AD. The findings were recently presented at the European Academy of Allergy and Clinical Immunology (EAACI) 2025 Congress.
The Phase 1/1b study of ZL-1503 is a randomized, double-blind, placebo-controlled trial involving single and multiple-ascending doses. The trial is designed to evaluate the safety, tolerability, and pharmacokinetics of ZL-1503 in healthy volunteers and participants with moderate to severe AD.
Rafael G. Amado, M.D., President, Head of Global Research and Development at Zai Lab, stated that the progress of ZL-1503 exemplifies the company’s global development capabilities. He added that ZL-1503 could provide a treatment option for patients managing their disease, and the company looks forward to evaluating its performance in the clinic.
Zai Lab is a biopharmaceutical company based in China and the United States. It focuses on discovering, developing, and commercializing products that address medical conditions with unmet needs in oncology, immunology, neuroscience and infectious disease.
Source: Zai Lab
