A Clinica Study of SCTC21C in Participants With Systemic Lupus Erythematosus

A Phase Ib/II Clinical Study Evaluating the Safety, Tolerability, Pharmacokinetics, and Efficacy of SCTC21C in Participants With Systemic Lupus Erythematosus

The purpose of this study is to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of SCTC21C in participants with systemic lupus erythematosus

Study Overview

• Status: Not yet recruiting
• Conditions: Systemic Lupus Erythematosus (SLE)
• Intervention / Treatment: Biological: SCTC21C

Detailed Description

This study contains phase Ib and phase II studies. In phase Ib study, participants will be assigned to receive sequentially higher doses of SCTC21C to determine the recomended dose of SCTC21C for the randomized dose optimation-stage. In phase 2 study, 2 dose levels will be uased. A total of 120 participants will be randomized in a 1:1:1 ration to dose 1, dose 2 or placebo groups to better understand the exposure/efficacy/toxicity relationship.

• Study Type: Interventional
• Enrollment (Estimated): 159
• Phase: Phase 2; Phase 1

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Aged 18-75 years;
2. Diagnosed with SLE for ≥12 weeks prior to screening, met the 2019 ACR/EULAR diagnostic criteria for SLE screening period;
3. SELENA-SLEDAI ≥8 at screening;
4. Positive immunological markers within 12 months prior to baseline;
5. Currently receiving ≥1 stable doses of standard treatment: oral corticosteroids, antimalarials, or conventional immunosuppressive drugs;
6. All male participants or females of reproductive potential must agree to use reliable contraception with their partner from signing the ICF through 5 months after the last dose of the study drug
7. Understanding of the study procedures and voluntary signing of the informed consent form

Exclusion Criteria:

1. Severe active or unstable lupus-related neuropsychiatric disorders;
2. Combined with active infections, malignant tumors, or other autoimmune diseases;
3. Catastrophic antiphospholipid syndrome;
4. severe lupus nephritis;
5. Study participants who received a live or attenuated vaccine within 28 days prior to baseline or during the screening period;
6. Received any investigational treatment within 30 days prior to baseline or within 5 half-lives of the investigational drug (whichever is longer);
7. Patients at high risk of severe clinical bleeding, or those requiring plasma transfusion, intravenous immunoglobulin, or acute blood products;;
8. Patients who experienced any of the following cardiovascular or cerebrovascular events within 24 weeks prior to baseline: myocardial infarction, unstable angina, ventricular arrhythmia, New York Heart Association (NYHA) Class II or higher heart failure, stroke, etc.;
9. In accordance with the protocol requirements, participants with abnormal laboratory test results;
10. Participants with positive results of viral serology, including Treponema pallidum, HIV, HCV, and HBV;
11. participants with a history of tuberculosis or latent tuberculosis infection;
12. Diagnosed with type 1 or type 2 diabetes with poor control;
13. Uncontrolled hypertension;
14. Intolerance to the study drug or contraindications, including a history of severe allergic reactions to monoclonal antibodies or any component of SCTC21C injection;
15. Required hospitalization for major surgery within 4 weeks prior to screening or within 12 weeks post-study drug administration;
16. History of solid organ or hematopoietic stem cell/bone marrow transplant, or expected to undergo transplant surgery during the study;
17. Pregnant or breastfeeding;
18. Any other condition that the investigator deems unsuitable for participation in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: experimental: SCTC21C; SCTC21C will be administered to participants for about 24 weeks	Biological: SCTC21C; SCTC21C will be subcutaneously administered at a dose as specified in the respective dose-escalation cohorts. Then, the RP2D and other appropriate doses of SCTC21C will be applied for the dose-expansion cohorts

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Phase 1: safety and tolerability of SCTC21C	To evaluate the incidence rates of treatment emergent adverse event (TEAE), treatment-related TEAE (TRAE), serious adverse event (SAE) and dose-limiting toxicity (DLT)	From first dose to Week 48
Phase II: efficacy of SCTC21C	Percentage of participants who achiened an mSRI-4 response at W24	Up to Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
dose escalation part#SRI4/5/6/7/8	percentage of participants who achieved SRI4/5/6/7/8 response at specified time	up to Week 48
Dose- escalation # mSRI4/5/6/7/8	percentage of participants who achieved mSRI4/5/6/7/8 response at specified time	up to Week 48
Dose-escalation part # BILAG	The BILAG improvement rate among participants with baseline BILAG score of A or B at specified time	up to Week 48
Dose-escalation part # SLE flare	Time to first SLE flare	Up to Week 48
Dose-escalation part # immunogenicity	Serum anti-SCTC21C antibody and anti-SCTC21C neutralization antibody levels	up to Week 48
Dose-escalation part # SCTC21C	Serum SCTC21C levels at specified time	up to Week 48

Collaborators and Investigators

• Sponsor: Sinocelltech Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): April 1, 2027
• Study Completion (Estimated): April 1, 2028

Study Registration Dates

• First Submitted: April 12, 2026
• First Submitted That Met QC Criteria: April 12, 2026
• First Posted (Actual): April 20, 2026

Study Record Updates

• Last Update Posted (Actual): April 20, 2026
• Last Update Submitted That Met QC Criteria: April 12, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: SLE
• Additional Relevant MeSH Terms: Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic
• Other Study ID Numbers: SCTC21C-C201

Drug and device information, study documents

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