A Phase 1 Study to Evaluate Pharmacokinetics, Safety and Tolerability of ZL-1503 in Healthy Volunteers

A Phase 1, Randomized, Open-label, Parallel-group Study to Evaluate the Pharmacokinetics, Safety and Tolerability of ZL-1503 Following a Single Dose of Subcutaneous or Intravenous Administration in Healthy Volunteers.

This is a phase 1, single dose, randomized, open-label, parallel-group study to evaluate the pharmacokinetics (PK), safety, tolerability and immunogenicity of ZL-1503 and to explore its PD biomarkers following a single subcutaneous (SC) or intravenous (IV) administration in healthy volunteers.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy Volunteers
• Intervention / Treatment: Drug: ZL-1503; Drug: ZL-1503; Drug: ZL-1503

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: ZaiLab Medical Director; Phone Number: +86 021-61632588; Email: ZL-1503-002_StudyTeam@zailaboratory.com

Study Locations

• New Zealand
  • Auckland
    • Auckland, Auckland, New Zealand
      • ZaiLab Site 18001

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ZL-1503 (Intravenous Administration)	Drug: ZL-1503; Healthy volunteers will receive a single intravenous dose of ZL-1503.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 1.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 2.
Experimental: ZL-1503 (Subcutaneous Dose 1)	Drug: ZL-1503; Healthy volunteers will receive a single intravenous dose of ZL-1503.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 1.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 2.
Experimental: ZL-1503 (Subcutaneous Dose2)	Drug: ZL-1503; Healthy volunteers will receive a single intravenous dose of ZL-1503.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 1.; Drug: ZL-1503; Healthy volunteers will receive a single subcutaneous administration at Dose 2.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Maximum plasma concentration (Cmax)	From Predose to Day 337
Time to maximum concentration (Tmax)	From Predose to Day 337
Area under the plasma concentration-time curve from time 0 to last quantifiable concentration (AUClast)	From Predose to Day 337
Area under the plasma concentration-time curve from time zero to infinity (AUCinf)	From Predose to Day 337
Apparent terminal elimination half-life (t1/2)	From Predose to Day 337
Apparent total body clearance (CL/F)	From Predose to Day 337
Apparent volume of distribution (Vz/F)	From Predose to Day 337
Steady State Volume of distribution (Vss IV)	From Predose to Day 337
Total Body Clearance (CL IV)	From Predose to Day 337
Absolute bioavailability (F)	From Predose to Day 337

Collaborators and Investigators

• Sponsor: Zai Lab (Shanghai) Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): September 3, 2026
• Primary Completion (Estimated): February 6, 2027
• Study Completion (Estimated): November 10, 2027

Study Registration Dates

• First Submitted: June 10, 2026
• First Submitted That Met QC Criteria: June 18, 2026
• First Posted (Actual): June 22, 2026

Study Record Updates

• Last Update Posted (Actual): June 22, 2026
• Last Update Submitted That Met QC Criteria: June 18, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Healthy volunteers
• Other Study ID Numbers: ZL-1503-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No