Safety, Tolerability, and Pharmacokinetic/Pharmacodynamic (PK/PD) Profile of ACT100 in Healthy Participants..

A Single-Center, Randomized, Double-Blind, Dose-Escalation, Placebo-Controlled, Phase Ia Study to Evaluate the Safety, Tolerability, and Pharmacokinetic/Pharmacodynamic (PK/PD) Profile of ACT100 in Healthy Participants.

This study is a Phase Ia, single-center, randomized, double-blind, dose-escalation, placebo-controlled clinical trial designed to evaluate the safety, tolerability, and pharmacokinetic/pharmacodynamic (PK/PD) profile of ACT100 in healthy participants. A total of 6 dose cohorts are planned, with each cohort enrolling 8 participants (including both male and female participants, where 6 will receive the investigational drug and 2 will receive placebo). The total planned enrollment is 48 healthy participants.

Study Overview

• Status: Not yet recruiting
• Conditions: Systemic Lupus Erythematosus; Cutaneous Lupus Erythematosus
• Intervention / Treatment: Drug: ACT100 Injection; Drug: ACT100 Injection; Drug: ACT100 Injection; Drug: ACT100 Injection; Drug: ACT100 Injection; Drug: ACT100 Injection; Drug: Placebo for ACT100; Drug: Placebo for ACT100; Drug: Placebo for ACT100; Drug: Placebo for ACT100; Drug: Placebo for ACT100; Drug: Placebo for ACT100

• Study Type: Interventional
• Enrollment (Estimated): 48
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Xiaohong Han; Phone Number: 050-69154796; Email: hanxiaohong@pumch.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Participants must voluntarily participate and sign the informed consent form after being informed of the entire trial process and the potential adverse reactions of the investigational product.
2. Healthy male and female participants aged between 18 and 55 years (inclusive) at the time of signing the informed consent form.
3. Body mass index (BMI) at screening: 18.5 kg/m^2 ≤ BMI < 28 kg/m^2; body weight ≥ 50 kg (for males) / ≥ 45 kg (for females).
4. At screening, physical examination, vital signs, laboratory tests, electrocardiogram (ECG), etc., are all normal or show abnormalities judged by the investigator as having no clinical significance.
5. Females of childbearing potential and males must agree to use highly effective contraceptive methods (e.g., intrauterine device, condom) from screening until 3 months after administration of the investigational product and have no plan for sperm or egg donation.

Exclusion Criteria:

1. History of treatment with any drug targeting the same molecule (BDCA2) as the investigational product.
2. A 12-lead electrocardiogram (ECG) at screening showing abnormalities considered clinically significant by the investigator (e.g., QTcF > 450 ms for males or > 470 ms for females).
3. History of severe diseases of major organ systems, including but not limited to neurological, cardiovascular, hematological, autoimmune, renal, hepatic, gastrointestinal, pulmonary, endocrine, metabolic, or psychiatric disorders.
4. Presence of severe bacterial or viral infection (e.g., pneumonia, sepsis, herpes zoster), or fungal/parasitic infection within 2 months prior to screening; or any symptoms of active or suspected infection within 1 week prior to dosing.
5. Chronic infectious diseases such as chronic hepatitis B or C, AIDS, tuberculosis, etc. Exclusion applies if any of the following tests are positive at screening: Hepatitis B surface antigen (HBsAg), Hepatitis B core antibody (HBcAb), Hepatitis C antibody (HCVAb), Treponema pallidum antibody, Human Immunodeficiency Virus antibody (HIVAb); or if there is evidence of active or latent Mycobacterium tuberculosis infection at screening.
6. History of primary immunodeficiency, splenectomy, or any other underlying condition deemed by the investigator to confer a high risk of severe infection.
7. History of severe food or drug allergy, or known allergy to monoclonal antibodies.
8. Vaccination with a live attenuated vaccine within 1 month prior to screening, or any other vaccination within half a month prior to screening, or plans to receive any vaccine during the study period.
9. Use of any prescription drugs, over-the-counter medications (including Chinese herbal medicines, health supplements, etc.) within 14 days prior to the first dose of the investigational product, unless deemed by both the investigator and sponsor to have no impact on the study.
10. History of drug abuse, illicit drug use, or alcohol abuse (history of drug abuse or illicit drug use within the past 5 years; or habitual alcohol intake exceeding 14 units per week within 3 months prior to screening: 1 unit ≈ 285 mL beer, or 25 mL spirits, or 100 mL wine). Participants with a positive alcohol breath test or positive urine drug abuse screening at screening will be excluded.
11. Heavy smoking (averaging >5 cigarettes per day) within 3 months prior to screening, or unwillingness to refrain from smoking during the study period.
12. Donation or loss of >400 mL of blood within 3 months prior to screening, or >200 mL within 1 month prior to screening; or receipt of blood transfusion or blood products within 3 months prior to screening.
13. Participation in another clinical trial involving an investigational drug/therapy within 1 month prior to screening, or within 5 half-lives (based on the known half-life of the prior investigational product, the Investigator's Brochure, or the informed consent form, whichever specifies the longer period).
14. History of blood/needle phobia or intolerance to venipuncture, or abnormalities at the potential injection site deemed by the investigator to be unsuitable for subcutaneous administration.
15. Females who are pregnant or lactating.
16. Any other condition that, in the judgment of the investigator, makes the participant unsuitable for participation in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

12

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ACT100 Cohort 1	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 1	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection
Experimental: ACT100 Cohort 2	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 2	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection
Experimental: ACT100 Cohort 3	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 3	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection
Experimental: ACT100 Cohort 4	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 4	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection
Experimental: ACT100 Cohort 5	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 5	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection
Experimental: ACT100 Cohort 6	Drug: ACT100 Injection; a single 5-mg subcutaneous injection; Drug: ACT100 Injection; a single 25-mg subcutaneous injection; Drug: ACT100 Injection; a single 100-mg subcutaneous injection; Drug: ACT100 Injection; a single 300-mg subcutaneous injection; Drug: ACT100 Injection; a single 600-mg subcutaneous injection; Drug: ACT100 Injection; a single 800-mg subcutaneous injection
Placebo Comparator: Placebo Group for Cohort 6	Drug: Placebo for ACT100; a single 5-mg subcutaneous injection; Drug: Placebo for ACT100; a single 25-mg subcutaneous injection; Drug: Placebo for ACT100; a single 100-mg subcutaneous injection; Drug: Placebo for ACT100; a single 300-mg subcutaneous injection; Drug: Placebo for ACT100; a single 600-mg subcutaneous injection; Drug: Placebo for ACT100; a single 800-mg subcutaneous injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Adverse Event(AE)	Day 1-84
Serious Adverse Event	Day 1-84
blood pressure	Day 1-84
pulse	Day 1-84
respiration	Day 1-84
body temperature	Day 1-84
Number of Participants with Abnormal Physical examination parameters	Day 1-84
Number of Participants with Abnormal Laboratory Parameters Findings	Day 1-84
Number of Participants with 12-Lead Electrocardiogram Findings	Day 1-84

Secondary Outcome Measures

Outcome Measure	Time Frame
Area Under the plasma concentration-time Curve from time zero to the last measurable concentration(AUC₀-t)	Day 1-4,7,14,21,28,42,56,70,84
Area Under the plasma concentration-time Curve from time zero extrapolated to infinity(AUC₀-∞)	Day 1-4,7,14,21,28,42,56,70,84
Maximum observed plasma concentration(Cmax)	Day 1-4,7,14,21,28,42,56,70,84
Time to reach the maximum observed plasma concentration(Tmax)	Day 1-4,7,14,21,28,42,56,70,84
Terminal elimination half-life(t1/2)	Day 1-4,7,14,21,28,42,56,70,84
Apparent clearance (CL/F)	Day 1-4,7,14,21,28,42,56,70,84
Apparent volume of distribution(Vd/F)	Day 1-4,7,14,21,28,42,56,70,84
Levels of BDCA2 on the surface of plasmacytoid dendritic cells (pDCs)	Day 1-3,7,14,28,42,56,70,84
Peripheral blood pDC levels	Day 1-3,7,14,28,42,56,70,84
Anti-drug antibodies (ADA).	Day 1,28,56,84
Neutralizing antibodies (NAb)	Day 1,28,56,84

Collaborators and Investigators

• Sponsor: Xiamen Amoytop Biotech Co., Ltd.
• Collaborators: Peking Union Medical College Hospital
• Investigators: Principal Investigator: Xiaohong Han, Peking Union Medical College Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 6, 2026
• Primary Completion (Estimated): March 30, 2027
• Study Completion (Estimated): October 30, 2027

Study Registration Dates

• First Submitted: February 6, 2026
• First Submitted That Met QC Criteria: February 6, 2026
• First Posted (Actual): February 13, 2026

Study Record Updates

• Last Update Posted (Actual): February 13, 2026
• Last Update Submitted That Met QC Criteria: February 6, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Systemic Lupus Erythematosus; Cutaneous Lupus Erythematosus; Pharmacokinetics and Pharmacodynamics; ACT100
• Additional Relevant MeSH Terms: Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin Diseases; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic; Lupus Erythematosus, Cutaneous
• Other Study ID Numbers: ACT100-4-1-001

Drug and device information, study documents

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