Zai Lab to Present Data From First Clinical Trial Evaluating ZL — 1503, an IL — 13/IL — 31Rα Bispecific Antibody, for Atopic Diseases

m. m. HKT Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) today announced that data from the first clinical trial evaluating ZL-1503, the company’s internally developed interleukin-13 (IL-13) and interleukin-31 (IL-31)Rα bispecific antibody, will be shared for the first time at the American College of Allergy, Asthma & Immunology (ACAAI) 2026 Annual Scientific Meeting, taking place November 12-16, 2026, in Phoenix, AZ. “Atopic dermatitis and other IL-13- and IL-31-driven diseases can severely impact patients’ health and quality of life,” said Rafael G.

, President, Head of Global Research and Development at Zai Lab. “Preclinically, ZL-1503 has shown the potential to provide relief of pruritus and inflammation in atopic diseases with less frequent dosing than other biologic therapies. ” ZL-1503 is a novel, long-acting, potentially first-in-class treatment for moderate-to-severe atopic dermatitis and other IL-13- and IL-31-driven diseases. IL-13 and IL-31 are key mediators in atopic disease (AD).

IL-13 promotes Type 2 inflammation and tissue changes, while IL-31 drives itch and amplifies local immune responses. Together, these cytokines perpetuate the itch-scratch-inflammation cycle that contributes to the development and persistence of atopic dermatitis and related conditions. Zai Lab engineered ZL-1503 to disrupt this cycle by simultaneously blocking both IL-13 and IL-31 receptor-mediated signaling. Preclinical data presented earlier this year showed that ZL-1503 provided rapid itch relief and significantly reduced inflammation in animal models of atopic diseases.

Findings from the Phase 1/1b first-in-human trial in healthy volunteers (NCT07235384) to be shared at ACAAI 2026 will include pharmacokinetic data following single-dose administration, as well as pharmacodynamic data on AD-related biomarkers across a range of ZL-1503 doses. The ACAAI presentation will also include initial safety and immunogenicity data. m. m.

m. m. HKT Registration available at: Webcast presentation (preferred): Dial-in: Presenters: Rafael G. , President, Head of Global Research and Development, Zai Lab About Zai Lab Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688) is an innovative, research-based, commercial-stage biopharmaceutical company based in China and the United States.

We are focused on discovering, developing, and commercializing innovative products that address medical conditions with significant unmet needs in the areas of oncology, immunology, neuroscience, and infectious disease. Our goal is to leverage our competencies and resources to positively impact human health.

For additional information about Zai Lab, please visit or follow us at or Zai Lab Forward-Looking Statements This press release contains forward-looking statements relating to our future expectations, plans, and prospects, for Zai Lab, including, without limitation, statements relating to our prospects and plans for developing and commercializing ZL-1503, and the potential treatment of atopic dermatitis and other type 2 helper T-cell (TH2)-driven diseases.

All statements, other than statements of historical fact, included in this press release are forward-looking statements, and can be identified by words such as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “plan,” “possible,” “potential,” “will,” “would,” and other similar expressions. Such statements constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are not guarantees or assurances of future performance.

Forward-looking statements are based on our expectations and assumptions as of the date of this press release and are subject to inherent uncertainties, risks and changes in circumstances that may differ materially from those contemplated by the forward-looking statements. We may not actually achieve the plans, carry out the intentions or meet the expectations or projections disclosed in our forward-looking statements, and you should not place undue reliance on these forward-looking statements. S. Securities and Exchange Commission (SEC).

We anticipate that subsequent events and developments will cause our expectations and assumptions to change, and we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as may be required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press release. com)