FXS6837 for the Treatment of IgAN Patients

A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of FXS6837 in IgAN Patients

This is a multicenter, randomized, double-blind, placebo controlled Phase IIb study to explore the efficacy and safety of FXS6837 capsules in IgAN patients. About 60 patients dignosed with primary IgAN will be enrolled and randomized to three cohorts and take different dosage of FXS6837 or placebo capsules orally according to protocol.

Study Overview

• Status: Not yet recruiting
• Conditions: IgAN
• Intervention / Treatment: Drug: FXS6837 Dose 1; Drug: FXS6837 Dose 2; Drug: Placebo Capsule

Detailed Description

This is a multicenter, randomized, double-blind, placebo-controlled study in approximately 60 patients with primary IgA nephropathy (IgAN).

Participants receiving background therapy will be randomized in a 1:1:1 ratio to receive FXS6837 capsules dose 1,dose 2, or placebo, administered orally once daily.

The study aims to evaluate the efficacy and safety of FXS6837 in patients with primary IgAN and to identify the optimal clinical dose.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2

Contacts and Locations

• Study Contact: Name: Jicheng LV, Doctor; Phone Number: +86-10-83572211; Email: jichenglv@bjmu.edu.cn
• Study Contact Backup: Name: Yang Li, Doctor; Phone Number: +86-10-83572211; Email: liyang_3337@163.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100034
      • Peking University First Hospital
      • Contact: Wang; Phone Number: 801 +86-10-66119025; Email: bdyyec@163.com
      • Contact: Yu; Phone Number: 802 +86-10-66119025; Email: bdyyec@163.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion criteria:

1. Adult male or female patients aged ≥18 years with biopsy-confirmed primary IgA nephropathy (IgAN), meeting all of the following:

   1. A qualifying renal biopsy performed within the past 8 years;
   2. ≤50% tubulointerstitial fibrosis;
   3. Crescent formation present in ≤50% of glomeruli;
   4. If a historical biopsy is not available, a biopsy may be performed during screening.
2. Estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m² at screening and at the end of the run-in period.
3. Urine protein-to-creatinine ratio (UPCR) ≥0.75 g/g at screening and at the end of the run-in period.
4. Vaccination against Neisseria meningitidis and Streptococcus pneumoniae is required prior to initiation of study treatment. If not previously vaccinated or if a booster is required, 5. vaccination should be administered according to local regulations at least 2 weeks prior to first dose. If treatment must begin earlier, prophylactic antibiotic therapy should be initiated.
5. Patients must have received a stable dose of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB), at the locally approved maximum daily dose or maximally tolerated dose (per investigator judgment), for at least 90 days prior to first dose. If receiving sodium-glucose cotransporter-2 inhibitors (SGLT2i), endothelin receptor antagonists (ERA), or hydroxychloroquine, doses must also be stable for at least 90 days prior to first dose (per investigator judgment).

Exclusion criteria:

1. Secondary IgA nephropathy (IgAN), as defined by the investigator.
2. Rapidly progressive IgAN, defined as ≥50% decline in eGFR (CKD-EPI) within 3 months, or <50% decline but considered by the investigator to be at risk of rapid renal function deterioration.
3. Other systemic diseases associated with proteinuria or chronic kidney disease (e.g., diabetic nephropathy, lupus nephritis, ANCA-associated vasculitis), or severe urinary tract obstruction or dysuria.
4. Prior treatment with immunosuppressive agents, including but not limited to cyclophosphamide, rituximab, infliximab, eculizumab, canakinumab, mycophenolate mofetil (MMF), mycophenolate sodium (MPS), cyclosporine, tacrolimus, sirolimus, everolimus, or systemic corticosteroids within 90 days (or 5 half-lives, whichever is longer) prior to first dose.
5. Prior treatment with oral budesonide (Nefecon®) within 6 months prior to first dose.
6. Prior treatment with other complement inhibitors within 30 days (or 5 half-lives, whichever is longer) prior to first dose.
7. Positive test results for HIV; active syphilis infection; chronic hepatitis B infection (HBsAg positive with HBV DNA > lower limit of quantification [LOQ]); or hepatitis C infection (positive HCV antibody with detectable HCV RNA).
8. Active tuberculosis at screening.
9. Clinically significant abnormal liver function at screening, defined as any of the following: ALT, AST, GGT, or ALP >3 × upper limit of normal (ULN), or total bilirubin >2 × ULN.
10. History of meningococcal infection.
11. Active systemic bacterial, viral (including COVID-19), or fungal infection within 14 days prior to first dose, or body temperature >38°C within 7 days prior to first dose.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm1：FXS6837 Dose 1; Once daily	Drug: FXS6837 Dose 1; FXS6837 taken orally once a day; Other Names: Dose 1
Experimental: Arm2：FXS6837 Dose 2; Once daily	Drug: FXS6837 Dose 2; FXS6837 taken orally once a day; Other Names: Dose 2
Placebo Comparator: Arm3：Placebo; Once daily	Drug: Placebo Capsule; Placebo taken orally once a day; Other Names: Placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Ratio to baseline in Urine Protein to Creatinine Ratio (sampled from 24h urine collection) at Day180	baseline and Day180

Secondary Outcome Measures

Outcome Measure	Time Frame
Ratio to baseline in Urine Protein to Creatinine Ratio at Day90	baseline and Day90
Ratio to baseline in Urine Protein to Creatinine Ratio	up to Day180
Ratio to baseline in Urine Albumin to Creatinine Ratio	up to Day180
Ratio to baseline in Urinary protein excretion（UPE）	up to Day180
Ratio to baseline in Urinary Albumin excretion（UAE）	up to Day180
Change from baseline of serum creatinine	up to Day180
Change from baseline of estimated glomerular filtration rate（eGFR）	up to Day180

Collaborators and Investigators

• Sponsor: Shanghai Fosun Pharmaceutical Industrial Development Co. Ltd.
• Investigators: Principal Investigator: Jicheng Lv, Doctor, Peking University First Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 31, 2026
• Primary Completion (Estimated): September 12, 2027
• Study Completion (Estimated): November 14, 2027

Study Registration Dates

• First Submitted: March 15, 2026
• First Submitted That Met QC Criteria: March 27, 2026
• First Posted (Actual): March 31, 2026

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 27, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: FXS6837-IIb-201

Drug and device information, study documents

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