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

Not Applicable

Not yet recruiting

• Conditions: Atopic Dermatitis (AD)
• Interventions: Drug: ZL-1503; Drug: Placebo

• Registration Number: NCT07235384
• Lead Sponsor: Zai Lab (Shanghai) Co., Ltd.

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)

Detailed Description

The study consists of two parts:

* Part A: single ascending dose in healthy volunteers

* Part B: multiple ascending doses in adult participants with moderate to severe AD

Study Timeline

• Status Verified: 2025-11
• Study First Submitted: 2025-11-14
• Study First Submitted QC: 2025-11-14
• Last Update Submitted: 2025-11-14
• Study First Posted: 2025-11-19
• Last Update Posted: 2025-11-19
• Study Start: 2025-12-04
• Primary Completion: 2027-12-28
• Study Completion: 2027-12-28

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 84

Inclusion Criteria

• Part A:

  1. Healthy male and female volunteers, 18-65 years of age
  2. Body mass index (BMI) between ≥ 18.5 and < 32.5 kg/m2
  3. Negative pregnancy tests for women of childbearing potential.

• Part B:

  1. 18-65 years of age;

  2. BMI between ≥18.5 and <40.0 kg/m2

  3. Have a diagnosis of AD at least 12 months prior to Day 1;

  4. Moderate-to-severe AD at Screening and Baseline visit, defined as:

     1. Eczema Area and Severity Index (EASI) score ≥ 16;
     2. Affected Body Surface Area (BSA)≥ 10%;
     3. vIGA-AD™ score ≥ 3

  5. History of an inadequate response to treatment with topical medications

  6. Average peak pruritus numeric rating scale (PP-NRS) score ≥4 in the 7 days before randomization.

  7. Negative pregnancy tests for women of childbearing potential.

Exclusion Criteria

• Part A and B:

  1. 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.
  2. History of major metabolic, liver, kidney, hematologic or other significant disorders.
  3. Abnormal Electrocardiogram (ECG) findings
  4. Clinically relevant abnormal lab results, including low blood counts, or abnormal liver and kidney function.
  5. History of drug abuse or addiction within 6 months prior to screening
  6. Current smoker or use of any nicotine or tobacco containing products within the last 6 months prior to dosing.
  7. Donated >500mL blood within 2 months of dosing.

• For Part B only:

  1. Presence of dermatologic conditions and/or comorbidities that might confound the diagnosis of AD and/or might interfere with study assessments.
  2. Uncontrolled chronic disease that might require bursts of oral corticosteroids.
  3. Any other sound medical, psychiatric, and/or social reason as determined by the investigator.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
ZL-1503: Participants will receive single ascending doses of ZL-1503	ZL-1503	Part A: Single Ascending Dose (SAD)
ZL-1503: Participants will receive single ascending doses of ZL-1503	Placebo	Part A: Single Ascending Dose (SAD)
ZL-1503: Participants will receive multiple ascending doses of ZL-1503	ZL-1503	Part B: Multiple Ascending Dose (MAD)
ZL-1503: Participants will receive multiple ascending doses of ZL-1503	Placebo	Part B: Multiple Ascending Dose (MAD)

Primary Outcome Measures

Name	Time	Method
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

Trial Locations

Locations (1)

ZaiLab Site 18001; 🇳🇿 Auckland, Auckland, New Zealand