To Evaluate the Efficacy and Safety of SG301 SC Injection in Systemic Lupus Erythematosus

A Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Study to Evaluate the Efficacy and Safety of SG301 SC Injection in Patients With Systemic Lupus Erythematosus

This was a multicenter, randomized, double-blind, placebo-controlled Phase 2 clinical study. The primary objective was to evaluate the efficacy of SG301 SC injection in participants with Systemic Lupus Erythematosus (SLE) based on the Systemic Lupus Erythematosus Responder Index -4 (SRI-4) response rate. The secondary objectives were to assess the safety, pharmacokinetics, pharmacodynamics, and immunogenicity profiles of SG301 SC injection in these participants .

Study Overview

• Status: Recruiting
• Conditions: Systemic Lupus Erythematosus (SLE)
• Intervention / Treatment: Drug: SG301 SC Injection; Drug: SG301 SC Injection; Drug: SG301 SC placebo

Detailed Description

This was a multicenter, randomized, double-blind, placebo-controlled Phase II clinical study. The primary objective was to evaluate the efficacy of SG301 SC Injection in participants with systemic lupus erythematosus (SLE) as assessed by the SRI-4 score. The secondary objectives included assessing the safety, pharmacokinetics, pharmacodynamics, and immunogenicity profiles of SG301 SC injection in these participants.

Eligible participants were those diagnosed with SLE in accordance with the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria, with a Systemic Lupus Erythematosus Disease Activity Index - 2000 (SLEDAI-2K )score of ≥ 8 points and seropositivity for antinuclear antibody (ANA) or anti-double-stranded DNA (anti-dsDNA) antibody at the screening visit.

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Yue Song; Phone Number: +86-18511021346; Email: songyue@sumgenbio.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China
      • Recruiting
      • Peking University People's Hospital
      • Contact: Zhanguo Li, Doctor; Phone Number: +86-010-88378021
      • Contact: Yue Yang, Doctor; Phone Number: +86-010-88378021

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Voluntarily participate in the clinical study and sign a written informed consent form.
2. Participants must be diagnosed with SLE in accordance with the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatism (ACR) SLE classification criteria and have inadequate response to standard treatment, intolerance to standard treatment, or recurrent disease.
3. SLEDAI-2K score ≥ 8 points, with clinical features corresponding to a SLEDAI-2K score ≥ 4 points.
4. Positive serological test results for autoantibodies, defined as antinuclear antibody (ANA) positivity and/or anti-double-stranded DNA (anti-dsDNA) antibody positivity.
5. Body weight ≥ 35 kg.
6. Must have received standard treatment for at least 8 weeks before the first dose and maintained a stable dose of the treatment unchanged for at least 4 weeks before the first dose.
7. Participants of childbearing potential or whose partners are of childbearing potential must agree to use effective contraceptive measures throughout the entire study period and within 6 months after the last dose.

Exclusion Criteria:

1. Previous use of CD38 or monoclonal antibodies targeting CD38.
2. Active central nervous system (CNS) disease within 2 months before the first dose, or CNS disease that the investigator believes may require treatment with prohibited therapies specified in the protocol.
3. Diagnosis of mixed connective tissue disease or a history of any overlap syndrome between SLE and systemic sclerosis.
4. Laboratory abnormalities.
5. Current acute or chronic infection meeting any of the following criteria.
6. Participation in any other clinical trial within 4 weeks before the first dose (excluding participants who provided informed consent but did not receive trial treatment, or only received placebo).
7. Use of any targeted T or B lymphocyte drugs (e.g., rituximab) within 3 months before the first dose.
8. Receipt of any B cell-depleting drugs (such as belimumab, telitacicept) within 4 weeks or 5 half-lives (whichever is shorter) before the first dose.
9. Receipt of JAK inhibitor treatment within 2 weeks before the first dose.
10. Presence of severe cardiovascular and cerebrovascular diseases.
11. Mycobacterium tuberculosis infection.
12. Presence of HIV infection, active hepatitis B, or hepatitis C.
13. Known history of active syphilis.
14. History of major organ transplantation (e.g., heart, lung, kidney, liver) or hematopoietic stem cell/or bone marrow transplantation.
15. Other conditions that the investigator believes would prevent the participant from participating in the study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SG301 SC - A; SG301 SC Injection	Drug: SG301 SC Injection; One injection per week for 8 doses, followed by one injection every two weeks for another 8 doses, with a total of 16 injections administered.; Drug: SG301 SC Injection; One injection per week for 8 doses, followed by one injection every two weeks for another 8 doses, with a total of 16 injections administered, among which 2 injections are placebos
Experimental: SG301 SC -B; SG301 SC Injection	Drug: SG301 SC Injection; One injection per week for 8 doses, followed by one injection every two weeks for another 8 doses, with a total of 16 injections administered.; Drug: SG301 SC Injection; One injection per week for 8 doses, followed by one injection every two weeks for another 8 doses, with a total of 16 injections administered, among which 2 injections are placebos
Placebo Comparator: Placebo; SG301 SC Placebo	Drug: SG301 SC placebo; One injection per week for 8 doses, followed by one injection every two weeks for another 8 doses, with a total of 16 injections administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of subjects achieving Systemic Lupus Erythematosus Responder Index -4 (SRI-4)	SRI-4 response is defined as: Systemic Lupus Erythematosus Disease Activity Index - 2000 (SLEDAI-2K) reduction from baseline of ≥ 4 points;; No British Isles Lupus Assessment Group-2004 (BILAG-2004) worsening, defined as ≥ 1 new A or ≥ 2 new B items compared to baseline;; No worsening in Physician's Global Assessment (PGA), defined as an increase of ≥ 0.3 from baseline;	From baseline to week 25

Collaborators and Investigators

• Sponsor: Hangzhou Sumgen Biotech Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): March 26, 2026
• Primary Completion (Estimated): September 30, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: February 25, 2026
• First Submitted That Met QC Criteria: February 25, 2026
• First Posted (Actual): March 4, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: April 1, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin and Connective Tissue Diseases; Lupus Erythematosus, Systemic
• Other Study ID Numbers: CSG-301 SC-205

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