A Study of Anti-CD38 Monoclonal Antibody (SG301) Subcutaneous Injection in Children With Nephrotic Syndrome With Frequent Relapses or Steroid Dependence

Not Applicable

Recruiting

• Conditions: Nephrotic Syndrome in Children
• Interventions: Drug: SG301 Subcutaneous injection

• Registration Number: NCT07087314
• Lead Sponsor: Mao Jianhua

Brief Summary

This is an open - label study to evaluate the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of SG301 Subcutaneous injection in children with frequently relapsing or steroid - dependent nephrotic syndrome.

Detailed Description

This study will recruit children aged 6 - 18 with frequently relapsing or steroid - dependent nephrotic syndrome, who have morning urine protein \< 1 + or urine protein / creatinine \< 0.2 g/g (\<20 mg/mmol) for at least three consecutive days after steroid treatment.

The study will stratify participants into two age groups:≥6 - \<12 years and≥12 - \<18 years. Recruitment will start with the 12 - 18 - year - old group. After collecting sufficient safety and clinical pharmacology data to support moving to lower age groups, the 6 - 12 - year - old group will be recruited. For every 1 to 3 participants enrolled, there will be a phased data review to guide further recruitment.

The trial has three phases: screening (D - 28\~D - 1), treatment (12 - week), and follow - up (40 - week). The enrolled participants will be treated with 12 mg/kg SG301 Subcutaneous injection subcutaneously. They will receive weekly injections for the first six weeks, then every two weeks for three times, totaling nine injections.

Study Timeline

• Study First Submitted: 2025-07-09
• Study First Submitted QC: 2025-07-17
• Study First Posted: 2025-07-25
• Status Verified: 2025-08
• Study Start: 2025-08-25
• Last Update Submitted: 2025-08-28
• Last Update Posted: 2025-09-05
• Primary Completion: 2028-07-09
• Study Completion: 2029-07-09

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 30

Inclusion Criteria

1. Aged 6 - 18 years.
2. Steroid-sensitive nephrotic syndrome with frequent relapses (FRNS) or steroid dependence (SDNS).
3. Normal renal function: eGFR≥90 ml/min/1.73m².
4. After steroid treatment, morning urine protein<1 + or urine protein/creatinine<0.2 g/g (<20 mg/mmol) for ≥3 consecutive days.
5. Within 7 days before enrollment, blood tests (without growth factors or transfusions) must meet: hemoglobin>80 g/L; platelets>75×10⁹/L; neutrophils>1.5×10⁹/L.
6. Prothrombin time/INR≤1.5×ULN, unless due to anticoagulation.
7. No Tacrolimus, cyclosporine A, mycophenolate mofetil, belimumab, levamisole, azathioprine, or cyclophosphamide in prior 2 months; no rituximab or obinutuzumab in prior 6 months.

Exclusion Criteria

1. Family history of nephrotic syndrome, chronic glomerulonephritis, or uremia.
2. Alanine aminotransferase >2×ULN or total bilirubin>2×ULN with a sustained increase for 2 weeks.
3. HBsAg or HBcAb positive with Hepatitis B virus DNA above the lower limit of normal; Hepatitis C virus antibody - positive with Hepatitis C virus RNA positive; HIV antibody - positive.
4. Chronic active infections (e.g., Epstein-Barr Virus, Cytomegalovirus, tuberculosis) that may worsen with steroids/ immunosuppressants.
5. Acute active infection (excluding onychomycosis) requiring systemic antibiotics/antivirals.
6. Secondary nephrotic syndrome (e.g.,immunoglobulin A - associated, lupus nephritis); steroid - resistant nephrotic syndrome (SRNS).
7. Other autoimmune diseases, primary immunodeficiency, or malignancy.
8. Prior anti - cluster of differentiation 38 (CD38) treatment.
9. Live/attenuated vaccine receipt or major surgery (non - diagnostic) within 4 weeks before first dose.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
SG301 Subcutaneous injection	SG301 Subcutaneous injection	full - dose prednisone (60 mg/m²/day, up to 80 mg) for remission induction. After 3 days of negative urine protein, start SG301 Subcutaneous injection with steroid tapering. Taper prednisolone to 60 mg/m² (max 80 mg) every other day, reducing by 1/6 every 2 weeks, and stop after 3 months.

Primary Outcome Measures

Name	Time	Method
Incidence and rate of treatment-Emergent Adverse Events	From baseline through study completion, an average of 1 year	Number and percentage of adverse events which are calculated by worst CTCAE grade by CTCAE 5.0
Relapse free survival rate	Average 1 year per subject	Relapse free survival rate at 6 and 12 months

Secondary Outcome Measures

Name	Time	Method
Relapse frequency in times	From baseline through study completion, an average of 1 year	Proportion of relapsed participants
Time to Relapse	From baseline through study completion, an average of 1 year	Time to first relapse after enrollment
SG301 anti-drug antibodies	From baseline through study completion, an average of 1 year	Number of subjects positive for anti-SG301 anti-drug antibodies
pharmacokinetics : Ctrough	From baseline through study completion, an average of 1 year	The trough concentration of SG301
Serum creatinine	From baseline through study completion, an average of 1 year	Serum creatinine(SCr), SCr in mg/dl
Cumulative corticosteroid dose	From baseline through study completion, an average of 1 year	The total amount of corticosteroids used during the study period, and the total amount of corticosteroids used in the 6 months prior to enrollment
estimated glomerular filtration rate	From baseline through study completion, an average of 1 year	Estimated glomerular filtration rate (eGFR), eGFR in ml/min/1.73m²
Neutralizing antibodies against SG301	From baseline through study completion, an average of 1 year	the neutralizing antibody titer of anti-SG301 anti-drug antibodies

Trial Locations

Locations (3)

Henan Children's Hospital Zhengzhou Children's Hospital; 🇨🇳 Zhengzhou, Henan, China

Tongji Hospital affiliated to Tongji Medical College of Huazhong University of Science & Technology; 🇨🇳 Wuhan, Hubei, China

Children's Hospital, Zhejiang University School of Medicine; 🇨🇳 Hangzhou, Zhejiang, China