Zai Lab Presents Promising Preclinical Data on Bispecific Antibody for Atopic Diseases

ZL-1503 shows potential to treat itch and inflammation in atopic dermatitis and other conditions

Apr. 18, 2026 at 2:05pm

Got story updates? Submit your updates here. ›

An extreme macro, translucent X-ray photograph revealing the intricate internal structures of a human skin cell, with glowing lines highlighting the biological mechanisms that drive the inflammatory and pruritogenic responses characteristic of atopic diseases.A revealing X-ray view of the cellular processes underlying the inflammatory and itch-inducing symptoms of atopic diseases, which ZL-1503 aims to disrupt.Boston Today

Zai Lab Limited announced new preclinical data on its internally developed IL-13/IL-31Ra bispecific antibody ZL-1503, demonstrating the drug's ability to simultaneously suppress inflammatory and pruritogenic (itch-causing) pathways in models of atopic diseases like asthma, allergic conjunctivitis, and rhinitis. The findings, presented at the IMMUNOLOGY2026 conference, reinforce ZL-1503's potential as a first-in-class treatment option for moderate-to-severe atopic dermatitis and other IL-13 and IL-31-driven conditions.

Why it matters

Atopic diseases like atopic dermatitis are characterized by a persistent itch-scratch cycle driven by the inflammatory cytokines IL-13 and IL-31. Current treatments often fail to adequately address both the inflammatory and pruritogenic components of these conditions. ZL-1503's ability to simultaneously target these two key pathways could offer improved efficacy and faster onset of action compared to single-pathway inhibitors.

The details

In preclinical studies, a single dose of ZL-1503 produced sustained, dose-dependent inhibition of both IL-31-induced scratching and IL-13-dependent signaling over 112 days. A 10 mg/kg dose also significantly improved lung function, reduced airway inflammation in asthma, and alleviated symptoms of allergic rhinitis and conjunctivitis. Transcriptomic and histopathological analyses further demonstrated broad suppression of Th2-related inflammatory pathways, immune cell infiltration, and mast-cell activation across multiple tissues.

  • ZL-1503 is currently being evaluated in an ongoing global Phase 1/1b clinical trial that began in December 2025.
  • The preclinical data on ZL-1503 was presented at the IMMUNOLOGY2026 conference in Boston on April 18, 2026.

The players

Zai Lab Limited

A biopharmaceutical company focused on developing innovative therapies for unmet medical needs, particularly in oncology, autoimmune, and infectious disease areas.

ZL-1503

Zai Lab's internally developed IL-13/IL-31Ra bispecific antibody that is being evaluated as a potential first-in-class treatment for atopic dermatitis and other IL-13 and IL-31-driven diseases.

Got photos? Submit your photos here. ›

What’s next

Zai Lab initiated Phase 1/1b first-in-human studies of ZL-1503 in healthy volunteers and adult patients with moderate-to-severe atopic dermatitis in Australia, New Zealand, and China in December 2025.

The takeaway

ZL-1503's ability to simultaneously target the inflammatory and pruritogenic pathways underlying atopic diseases could offer improved efficacy and faster onset of action compared to single-pathway inhibitors, representing a potentially transformative new treatment option for patients suffering from these debilitating conditions.