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

NCT07235384 | Recruiting Phase 1 FDA Drug

• 1 other identifier: ZL-1503-001
• Study Type: interventional
• Target: 84
• Locations: 1 country
• Sites: 1

Brief Summary

This is a phase 1/1b randomized, double blind, placebo-controlled, single dose escalation (SAD) and multiple dose escalation (MAD) study to evaluate the safety, tolerability, and pharmacokinetics (PK) of ZL-1503 in healthy volunteers and participants with moderate to severe atopic dermatitis (AD)

Conditions

Atopic Dermatitis (AD)

Keywords

Atopic Dermatitis

Outcome Measures

Primary Outcomes (5)

• Number of participants with adverse events (AEs)

  Up to 48 weeks after last intervention

• Number of participants with serious adverse events (SAEs)

  Up to 48 weeks after last intervention

• Number of participants with clinical laboratory abnormalities

  Up to 48 weeks after last intervention

• Number of participants with vital sign abnormalities

  Up to 48 weeks after last intervention

• Number of participants with electrocardiogram (ECG) abnormalities

  Up to 48 weeks after last intervention

Study Arms (2)

ZL-1503: Participants will receive single ascending doses of ZL-1503

EXPERIMENTAL

Part A: Single Ascending Dose (SAD)

Drug: ZL-1503; Drug: Placebo

ZL-1503: Participants will receive multiple ascending doses of ZL-1503

EXPERIMENTAL

Part B: Multiple Ascending Dose (MAD)

Drug: ZL-1503; Drug: Placebo

Interventions

ZL-1503 DRUG

Healthy volunteers will receive ZL-1503.

ZL-1503: Participants will receive single ascending doses of ZL-1503

Placebo DRUG

Healthy volunteers will receive placebo.

ZL-1503: Participants will receive single ascending doses of ZL-1503

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Part A:
• Healthy male and female volunteers, 18-65 years of age
• Body mass index (BMI) between ≥ 18.5 and \< 32.5 kg/m2
• Negative pregnancy tests for women of childbearing potential.
• Part B:
• years of age;
• BMI between ≥18.5 and \<40.0 kg/m2
• Have a diagnosis of AD at least 12 months prior to Day 1;
• Moderate-to-severe AD at Screening and Baseline visit, defined as:
• Eczema Area and Severity Index (EASI) score ≥ 16;
• Affected Body Surface Area (BSA)≥ 10%;
• vIGA-AD™ score ≥ 3
• History of an inadequate response to treatment with topical medications
• Average peak pruritus numeric rating scale (PP-NRS) score ≥4 in the 7 days before randomization.
• Negative pregnancy tests for women of childbearing potential.

You may not qualify if:

• Part A and B:
• Significant health issues, such as positive tests for human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B surface antigen (HBsAg), active tuberculosis, immunodeficiencies or autoimmune diseases.
• History of major metabolic, liver, kidney, hematologic or other significant disorders.
• Abnormal Electrocardiogram (ECG) findings
• Clinically relevant abnormal lab results, including low blood counts, or abnormal liver and kidney function.
• History of drug abuse or addiction within 6 months prior to screening
• Current smoker or use of any nicotine or tobacco containing products within the last 6 months prior to dosing.
• Donated \>500mL blood within 2 months of dosing.
• For Part B only:
• Presence of dermatologic conditions and/or comorbidities that might confound the diagnosis of AD and/or might interfere with study assessments.
• Uncontrolled chronic disease that might require bursts of oral corticosteroids.
• Any other sound medical, psychiatric, and/or social reason as determined by the investigator.

Sponsors & Collaborators

• Zai Lab (Shanghai) Co., Ltd.: lead

Study Sites (1)

ZaiLab Site 18001

Auckland, Auckland, New Zealand

RECRUITING

MeSH Terms

Conditions

Dermatitis, Atopic

Condition Hierarchy (Ancestors)

Skin Diseases, Genetic; Genetic Diseases, Inborn; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; Dermatitis; Skin Diseases; Skin and Connective Tissue Diseases; Skin Diseases, Eczematous; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Central Study Contacts

ZaiLab Medical Director

CONTACT

+86 021-61632588; ZaiLab_1503-001_StudyTeam@zailaboratory.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 14, 2025
• First Posted: November 19, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): December 28, 2027
• Study Completion (Estimated): December 28, 2027
• Last Updated: December 19, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

NZ (1)