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
| ISRCTN | ISRCTN17949230 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN17949230 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | ZL-1503-001 |
| Sponsor | Zai Lab (Shanghai) Co., Ltd |
| Funder | Zai Lab (Shanghai) Co., Ltd |
- Submission date
- 03/11/2025
- Registration date
- 04/11/2025
- Last edited
- 03/11/2025
- Recruitment status
- Not yet recruiting
- Overall study status
- Ongoing
- Condition category
- Skin and Connective Tissue Diseases
Plain English summary of protocol
Background and study aims
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)
Who can participate?
SAD: Healthy male and non-pregnant, non-lactating female participants, 18-65 years of age, inclusive
MAD: Male and non-pregnant, non-lactating female participants with moderate to severe atopic dermatitis (AD), 18-65 years of age, inclusive
What does the study involve?
Participants are randomly assigned to receive either ZL-1503 or a placebo as a single dose or multiple doses to determine the safety and the way people process the drug. The total maximum study duration for participants is about 1 year.
What are the possible benefits and risks of participating?
No clinical benefit is anticipated for healthy volunteers. However, participants may benefit society by contributing to the process of developing new therapies in an area of unmet need. Additionally, participants will benefit from medical evaluations/assessments associated with study procedures (e.g., physical examination, electrocardiogram [ECG], labs, etc.).
Where is the study run from?
Zai Lab (Shanghai) Co., Ltd (China)
When is the study starting and how long is it expected to run for?
September 2025 to December 2027
Who is funding the study?
Zai Lab (Shanghai) Co., Ltd (China)
Who is the main contact?
ZaiLab_1503-001_StudyTeam@zailaboratory.com
Contact information
Public, Scientific, Principal investigator
Building B, 899 Halei Road, Pudong
Shanghai
201203
China
| Phone | +86 21 61632588 |
|---|---|
| ZaiLab_1503-001_StudyTeam@zailaboratory.com |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Multicenter interventional phase 1/1b randomized double blind placebo-controlled single and multiple dose escalation study |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | A phase 1/1b randomized, double blind, placebo-controlled, single and multiple dose escalation study to evaluate the safety, tolerability, and pharmacokinetics of ZL-1503 in healthy volunteers and participants with moderate to severe atopic dermatitis (AD) |
| Study objectives | The main objective of this study is to evaluate the safety and tolerability of ZL-1503. The secondary objectives are to evaluate the pharmacokinetics (PK) and immunogenicity of ZL-1503. The data obtained from this FIH study will inform dose selection for subsequent clinical development and will help with the design of future studies. |
| Ethics approval(s) |
Submitted 11/09/2025, Health and Disability Ethics Committee (133 Molesworth Street, Wellington, 6140, New Zealand; -; hdecs@health.govt.nz), ref: 2025FULL23878 |
| Health condition(s) or problem(s) studied | Safety and tolerability in healthy volunteers and participants with moderate to severe atopic dermatitis |
| Intervention | Healthy volunteers in the SAD part of the study will enrol sequentially into 4 single dose cohorts from New Zealand. Two additional cohorts of Chinese healthy volunteers will enrol sequentially in China. Within each cohort, participants will be randomized to receive a single IV dose of ZL-1503 or placebo. In the MAD part of the study, participants with moderate to severe atopic dermatitis will enrol sequentially into 2 multiple dose cohorts. Within each cohort, participants will be randomized to receive multiple IV doses of ZL-1503 or placebo. |
| Intervention type | Drug |
| Phase | Phase I |
| Drug / device / biological / vaccine name(s) | ZL-1503 |
| Primary outcome measure(s) |
Safety and tolerability of ZL-1503 assessed using incidence of Adverse Events (AEs) and serious adverse events (SAEs) coded based on the National Cancer Institute’s Common Terminology Criteria for Adverse Events (CTCAE). Incidence of clinically significant laboratory findings (Chemistry, Hematology. Urinalysis). Incidence of clinically significant vital signs include pulse rate measured via brachial/radial artery, blood pressure through digital Sphygmomanometer, body temperature, and respiratory rate. Incidence of clinically significant changes in electrocardiograms. |
| Key secondary outcome measure(s) |
1. PK parameters of ZL-1503 may include, but are not limited to, maximum serum concentration (Cmax), time to reach maximum concentration (Tmax), area under the concentration-time profile (AUC), half-life (t1/2), volume of distribution at steady-state (Vss), clearance (CL) and accumulation ratio, as applicable. |
| Completion date | 31/12/2027 |
Eligibility
| Participant type(s) | Healthy volunteer, Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 65 Years |
| Sex | All |
| Target sample size at registration | 84 |
| Key inclusion criteria | Part A (SAD): A1. Healthy male and female volunteers, 18-65 years of age A2. Body mass index (BMI) between ≥ 18.5 and < 32.5 kg/m² A3. Negative pregnancy tests for women of childbearing potential Part B (MAD): B1. 18-65 years of age B2. BMI between ≥18.5 and <40.0 kg/m² B3. Have a diagnosis of AD at least 12 months prior to Day 1 B4. Moderate-to-severe AD at Screening and Baseline visit, defined as: B4.1. Eczema Area and Severity Index (EASI) score ≥ 1 B4.2. Affected Body Surface Area (BSA)≥ 10% B4.3. vIGA-ADTM score ≥ 3 B5. History of an inadequate response to treatment with topical medications B6. Average peak pruritus numeric rating scale (PP-NRS) score ≥4 in the 7 days before randomization B7. Negative pregnancy tests for women of childbearing potential |
| Key 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 virus (HBV), 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. Part B only: B8. Presence of dermatologic conditions and/or comorbidities that might confound the diagnosis of AD and/or might interfere with study assessments. B9. Uncontrolled chronic disease that might require bursts of oral corticosteroids. B10. Any other sound medical, psychiatric, and/or social reason as determined by the investigator. |
| Date of first enrolment | 04/12/2025 |
| Date of final enrolment | 20/11/2026 |
Locations
Countries of recruitment
- China
- New Zealand
Study participating centre
Auckland
6022
New Zealand
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not expected to be made available |
| IPD sharing plan | Individual results from the clinical trial will not be made available to study participants or others. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
03/11/2025: Trial's existence confirmed by Health and Disability Ethics Committees.
