Zai Lab to Present First Clinical Data for ZL-1503 at ACAAI 2026

SHANGHAI and CAMBRIDGE, Mass., October 14, 2026

First-in-Human Study to Present Initial Clinical Findings

The Phase 1/1b trial, registered as NCT07235384, is evaluating ZL-1503 in healthy volunteers, with the initial presentation focusing on pharmacokinetic data following single-dose administration across a range of doses. Investigators will also report pharmacodynamic findings involving biomarkers associated with atopic dermatitis, alongside initial information on safety and immunogenicity. These assessments are important in early clinical development because they help characterize how a candidate behaves in the body, whether it affects relevant biological pathways and how participants respond to treatment. The poster is titled “First-in-Human, Single Ascending Dose Study of ZL-1503, a Half-Life-Extended Anti-IL-13/IL-31Rα Bispecific Antibody, in Healthy Volunteers.” It is scheduled for Friday, November 13, 2026, at 2:50 p.m. Mountain Time, with ePoster ID R376 and abstract number 8201. Zai Lab President and Head of Global Research and Development Rafael G. Amado, MD, is scheduled to discuss the findings and the company’s clinical development plans during an investor conference call and webcast on the same day. The announcement does not yet disclose the clinical data themselves; their interpretation will depend on the results presented at the meeting.

Dual Cytokine Targeting Addresses Itch and Inflammation

ZL-1503 is designed to block both IL-13 and IL-31 receptor-mediated signaling, targeting two pathways involved in atopic diseases. IL-13 contributes to type 2 inflammation and tissue changes, while IL-31 is associated with itching and local immune responses. These processes can reinforce the itch-scratch-inflammation cycle that contributes to the persistence of atopic dermatitis. By inhibiting both pathways with a single bispecific antibody, Zai Lab aims to address inflammatory activity and itch through one treatment candidate. The company is also developing ZL-1503 as a long-acting biologic, with the potential for less frequent administration than some existing biologic therapies. Earlier preclinical studies reported that the candidate provided rapid itch relief and significantly reduced inflammation in animal models of atopic diseases. These findings supported advancement into human testing but do not establish clinical benefit in patients. The upcoming healthy-volunteer results will help clarify the candidate’s pharmacokinetic profile, biological activity and early safety characteristics before its potential use in people with atopic dermatitis or related conditions can be assessed.

Clinical Development Plans and Investor Update

Zai Lab plans to discuss the ACAAI presentation and the next steps for ZL-1503 during an investor conference call scheduled for November 13, 2026, at 8:00 a.m. Eastern Time, corresponding to 9:00 p.m. Hong Kong Time. The webcast and registration details have been provided by the company. The clinical program is focused on establishing the candidate’s initial human safety and pharmacological profile while evaluating biological markers relevant to its intended mechanism of action. Further clinical studies will be needed to determine whether simultaneous IL-13 and IL-31Rα pathway inhibition can translate into meaningful and durable improvements for patients. Atopic dermatitis is an inflammatory skin disease that can involve persistent itching, skin irritation and substantial effects on quality of life. Zai Lab is a research-based, commercial-stage biopharmaceutical company operating in China and the United States, with development programs spanning oncology, immunology, neuroscience and infectious diseases. The company’s presentation of ZL-1503 at ACAAI 2026 will provide the first clinical update on this internally developed bispecific antibody and an opportunity to outline its plans for continued evaluation in atopic diseases.

Source::Invivyd press release