ZL-1503 / ZAI Lab - LARVOL DELTA

Anticipated Major Milestones:…ZL-1503 (IL-13/IL-31Rα) (Businesswire) - "Report initial first-in-human data from the SAD portion of the global Phase 1/1b study in healthy volunteers, including pharmacokinetics (PK), half-life, pharmacodynamic biomarkers (including pSTAT6), and safety, in the second half of 2026. Continue enrollment in the MAD portion of the Phase 1/1b study in patients with atopic dermatitis. Initial clinical data from the MAD portion expected in the first half of 2027."

First-in-human • P1 data • Trial status • Atopic Dermatitis

A Phase 1/1b Study to Evaluate Safety, Tolerability and Pharmacokinetics of ZL-1503 in Healthy Volunteers and Participants With Moderate to Severe Atopic Dermatitis (clinicaltrials.gov) - P1 | N=84 | Recruiting | Sponsor: Zai Lab (Shanghai) Co., Ltd. | Initiation date: Apr 2026 ➔ Dec 2025

Trial initiation date • Atopic Dermatitis • Dermatitis • Dermatology • Immunology

A Phase 1 Study to Evaluate Pharmacokinetics, Safety and Tolerability of ZL-1503 in Healthy Volunteers (clinicaltrials.gov) - P1 | N=36 | Not yet recruiting | Sponsor: Zai Lab (Shanghai) Co., Ltd.

New P1 trial

ZL-1503 (IL-13/IL-31Rα) (Zai Lab Press Release) - "A global Phase 1/1b study is underway with initial data expected in 2026."

P1 data • Atopic Dermatitis

ZL-1503: A Bispecific Antibody Targeting IL-13 and IL-31Rα Sustains Suppression of Pruritus and Atopic Disease in Non-Human Primates (IMMUNOLOGY 2026) - "ZL-1503 strongly inhibited IL-13/IL-31 pathways in primates and showed significant effects across atopic conditions in NHP models. These findings support its development for human trials targeting moderate-to-severe atopic dermatitis and other IL-13/IL-31 driven diseases."

Bispecific • Allergic Rhinitis • Asthma • Atopic Dermatitis • Dermatitis • Dermatology • Immunology • Inflammation • Pruritus • Respiratory Diseases • IL13 • STAT6

Zai Lab Presents New Preclinical Data Suggesting ZL-1503, an IL-13/IL-31Rα Bispecific Antibody, Provides Rapid Itch Relief and Reduction in Inflammation in Atopic Diseases (Businesswire) - "A single intravenous dose of ZL-1503 (0.3, 3, 10 mg/kg) produced sustained, dose-dependent inhibition of both IL-31-induced scratching and IL-13-dependent pSTAT6 signaling over a 112-day observation period, demonstrating durable pathway suppression. A single dose of 10 mg/kg also significantly improved lung function, reduced airway inflammation in asthma, and alleviated symptoms of allergic rhinitis and conjunctivitis."

Preclinical • Allergic Rhinitis • Asthma • Atopic Dermatitis • Conjunctivitis

ZL-1503: A Bispecific Antibody Targeting Inflammatory and Pruritogenic Pathways with a Prolonged Serum Half-life and Sustained Activity in Non-human Primates (AAD 2026) - "ZL-1503 exhibited sustained inhibition of inflammatory and pruritogenic pathways in NHP, supporting its progression to IND-enabling studies as a potential treatment for moderate-to-severe AD, and other IL-13 and IL-31-driven diseases."

Bispecific • Atopic Dermatitis • Dermatitis • Immunology • Inflammation • IL13

ZL-1503 (IL-13/IL-31Rα bispecific antibody): First-in-Human (FIH) data from the ongoing global Phase 1/1b study expected in the second half of 2026, paving the way for Phase 2 development in atopic dermatitis (AD). (Businesswire)

First-in-human • P1 data • Atopic Dermatitis

A Phase 1/1b Study to Evaluate Safety, Tolerability and Pharmacokinetics of ZL-1503 in Healthy Volunteers and Participants With Moderate to Severe Atopic Dermatitis (clinicaltrials.gov) - P1 | N=84 | Recruiting | Sponsor: Zai Lab (Shanghai) Co., Ltd. | Not yet recruiting ➔ Recruiting

Enrollment open • Atopic Dermatitis • Dermatitis • Dermatology • Immunology

Zai Lab Announces Dosing of First Participant in Global Phase 1/1b study of ZL-1503, an IL-13/IL-31R Bispecific Antibody for the Treatment of Atopic Dermatitis (Businesswire) - "The Phase 1/1b study of ZL-1503 is a randomized, double-blind, placebo-controlled single-dose and multiple-ascending dose trial designed to evaluate the safety, tolerability, and pharmacokinetics of ZL-1503 in healthy volunteers and participants with moderate to severe AD."

Trial status • Atopic Dermatitis

A Phase 1/1b Study to Evaluate Safety, Tolerability and Pharmacokinetics of ZL-1503 in Healthy Volunteers and Participants With Moderate to Severe Atopic Dermatitis (clinicaltrials.gov) - P1 | N=84 | Not yet recruiting | Sponsor: Zai Lab (Shanghai) Co., Ltd.

New P1 trial • Atopic Dermatitis • Dermatitis • Dermatology • Immunology

Immunology Pipeline: ZL-1503 (IL-13/IL-31R) (Businesswire) - "In November 2025, Zai Lab initiated a global Phase 1/1b study to evaluate safety, tolerability and pharmacokinetics of ZL-1503 in healthy volunteers and participants with moderate to severe atopic dermatitis."

Trial status • Atopic Dermatitis

Expected Clinical Developments and Data Readouts:…ZL-1503 (IL-13/IL-31R) (Businesswire) - "Zai Lab to provide the initial data readout from the global Phase 1/1b study in healthy volunteers and participants with moderate to severe atopic dermatitis in 2026."

P1 data • Atopic Dermatitis

Zai Lab Announces Second Quarter 2025 Financial Results and Recent Corporate Updates (Businesswire) - "ZL-1503 (IL-13/IL-31R): Zai Lab to advance into a global Phase 1 study in moderate-to-severe atopic dermatitis in the second half of 2025. Efgartigimod (FcRn): Lupus Nephritis (LN): Zai Lab and partner argenx to provide topline results from the Phase 2 study in LN in the fourth quarter of 2025. Seronegative gMG: Zai Lab partner argenx to provide topline results from the global Phase 3 ADAPT-SERON study in seronegative gMG in the second half of 2025. Zai Lab participated in the study in Greater China. Ocular myasthenia gravis: Zai Lab partner argenx to provide topline results from the global Phase 3 ADAPT-OCULUS study in the first half of 2026. Zai Lab participated in the study in Greater China. Sjogren's disease: Zai Lab to join the registrational UNITY study of efgartigimod subcutaneous given by prefilled syringe in Sjogren’s disease in Greater China in the third quarter of 2025."

New P1 trial • P2 data • P3 data: top line • Atopic Dermatitis • Lupus Nephritis • Myasthenia Gravis • Sjogren's Syndrome

ZL-1503: A Bispecific Antibody Targeting Inflammatory and Pruritogenic Pathways with a Prolonged Serum Half-life and Sustained Activity in Non-human Primates (EAACI 2025) - "These findings demonstrate strong PK/PD relationships of ZL-1503 in blocking IL-13 and IL-31 in the NHP model. Conclusion ZL-1503 exhibited sustained inhibition of inflammatory and pruritogenic pathways in NHP, supporting its progression to IND-enabling studies as a potential treatment for moderate-to-severe AD, and other IL-13 and IL-31-driven diseases."

Atopic Dermatitis • Dermatitis • Immunology • Inflammation • IL13

Zai Lab Presents New Preclinical Data for ZL-1503, an IL-13/IL-31R Bispecific Antibody for the Treatment of Atopic Dermatitis, at EAACI Congress 2025 (Businesswire) - "Key study results presented at the EAACI Congress 2025 include: An intravenous single dose of ZL-1503 (10 mg/kg, iv) completely inhibited IL-13-mediated pSTAT6 and IL-31-induced scratching for at least 76 days in all preclinical subjects. Two out of three subjects exhibited prolonged IL-13-mediated pSTAT6 inhibition for over 118 days, and one out of three subjects sustained IL-31-induced scratching inhibition for over 133 days....ZL-1503 was well tolerated following weekly IV dosing up to 150 mg/kg. Additionally, in vitro studies showed that binding to one target did not affect ZL-1503’s blocking effects on the other target."

Preclinical • Atopic Dermatitis

Zai Lab Announces Fourth Quarter and Full Year 2024 Financial Results and Recent Corporate Updates (Businesswire) - "ZL-1102 (IL-17 Humabody): Zai Lab to provide interim analysis in the global Phase 2 study in chronic plaque psoriasis in the first half of 2025. ZL-1503 (IL-13/IL-31R): Zai Lab to provide preclinical data update and initiate a global Phase 1 study in moderate-to-severe atopic dermatitis...Seronegative gMG: Zai Lab partner argenx to provide topline results from the Phase 3 ADAPT-SERON study in seronegative gMG. Zai Lab participated in the study in Greater China. Lupus Nephritis (LN): Zai Lab to provide topline results from the Phase 2 study in LN."

New P1 trial • P2 data • P3 data • Preclinical • Atopic Dermatitis • Lupus Nephritis • Myasthenia Gravis • Psoriasis

ZL-1503, a Bispecific, Serum Half-life Extended Antibody Targeting Both Inflammatory and Pruritogenic Pathways for Atopic Dermatitis and Other IL-13/IL-31 Related Diseases (EADV 2024) - No abstract available

Late-breaking abstract • Atopic Dermatitis • Dermatitis • Dermatology • Immunology • IL13

ZL-1503, a bispecific, serum half-life extended antibody targeting both inflammatory and pruritogenic pathways for atopic dermatitis and other IL-13/IL-31 related diseases (EADV 2024) - No abstract available

Late-breaking abstract • Atopic Dermatitis • Dermatitis • Dermatology • Immunology • IL13