Belimumab With Rituximab for Primary Membranous Nephropathy (REBOOT)

Efficacy of Belimumab and Rituximab Compared to Rituximab Alone for the Treatment of Primary Membranous Nephropathy (ITN080AI)

The primary objective of this study is to evaluate the effectiveness of belimumab and intravenous rituximab co-administration at inducing a complete remission (CR) compared to rituximab alone in participants with primary membranous nephropathy.

Background:

Primary membranous nephropathy (MN) is among the most common causes of nephrotic syndrome in adults. MN affects individuals of all ages and races. The peak incidence of MN is in the fifth decade of life.

Primary MN is recognized to be an autoimmune disease, a disease where the body's own immune system causes damage to kidneys. This damage can cause the loss of too much protein in the urine.

Drugs used to treat MN aim to reduce the attack by one's own immune system on the kidneys by blocking inflammation and reducing the immune system's function. These drugs can have serious side effects and often do not cure the disease. There is a need for new treatments for MN that are better at improving the disease while reducing fewer treatment associated side effects.

In this study, researchers will evaluate if treatment with a combination of two different drugs, belimumab and rituximab, is effective at blocking the immune attacks on the kidney compared to rituximab alone. Rituximab works by decreasing a type of immune cell, called B cells. B cells are known to have a role in MN. Once these cells are removed, disease may become less active or even inactive. However, after stopping treatment, the body will make new B cells which may cause disease to become active again.

Belimumab works by decreasing the new B cells produced by the body and, may even change the type of new B cells subsequently produced. Belimumab is approved by the US Food and Drug Administration (FDA) to treat systemic lupus erythematosus (also referred to as lupus or SLE). Rituximab is approved by the FDA to treat some types of cancer, rheumatoid arthritis, and vasculitis. Neither rituximab nor belimumab is approved by the FDA to treat MN. Treatment with a combination of belimumab and rituximab has not been studied in individuals with MN, but has been tested in other autoimmune diseases, including lupus nephritis and Sjögren's syndrome.

Study Overview

• Status: Active, not recruiting
• Conditions: Nephrotic Syndrome; Membranous Nephropathy
• Intervention / Treatment: Drug: Rituximab; Drug: Belimumab; Drug: Placebo for Belimumab

Detailed Description

This trial is a two-part study (Part A and Part B) of adults with primary membranous nephropathy (MN), ages 18-75 inclusive. The study will be conducted at multiple sites in the United States and Canada.

Part A: Open-label Phase

Part A is an open-label, PK study to compare belimumab exposure between participants who have "low" proteinuria (≥ 4 to < 8 g/day) and "high" proteinuria (≥ 8 g/day) at Visit -1.

Initially Part A planned to enroll 20 individuals with primary MN: 10 individuals with low proteinuria and 10 individuals with high proteinuria. All Part A participants received 200 mg subcutaneous belimumab weekly, the initially approved dose of belimumab in SLE, for 52 doses (weeks 0-51). Trough serum belimumab levels would be obtained weekly following the first 4 doses of belimumab. All participants would receive rituximab 1000 mg IV at weeks 4 and 6, and are followed after the 52 week treatment period on no study medication until week 156.

Belimumab trough levels were to be analyzed after all 20 participants received the first 4 doses to compare the belimumab exposure between the low and high proteinuria groups. If the belimumab exposure was not comparable between the high and low proteinuria groups, the belimumab dose would be doubled to 400 mg/weekly for participants with high proteinuria in Part B. Dose determination for participants with high proteinuria in Part B would be made by an adjudication committee comprised of the Protocol Chair, NIAID Medical Monitor, ITN Clinical Trial Physician, and Rho Scientist, in consultation with the belimumab PK expert at GSK.

Due in part to the observed imbalance in enrollment between the high and low proteinuria groups, an ad hoc PK analysis was conducted. The serum belimumab trough levels of the first 12 participants (8 with high proteinuria and 4 with low proteinuria) who received the first 4 belimumab doses were analyzed to compare belimumab exposure between the low and high proteinuria groups.

The results of the PK analysis were reviewed by the adjudication committee, who determined that the results did not support doubling the dose of belimumab in individuals with high proteinuria nor did it identify a new proteinuria threshold that warranted an increased belimumab dose. The belimumab PK expert at GSK concurred. Thus, enrollment into Part A has been suspended, and all participants in Part B are to receive the same dose of belimumab. All participants currently enrolled in Part A continue to receive belimumab and rituximab as previously planned and are undergoing the safety assessments as presented in Appendix A.

All enrolled participants in Part A will be followed until week 156 and will be assessed for the same study endpoints as participants in Part B.

Part B: Randomized Phase

Part B is a prospective, randomized, phase II, double-blind, placebo-controlled, multicenter clinical trial in adults with primary MN. Part B is commencing after the completion of the ad hoc PK analysis, which did not support increasing the belimumab dose in participants with high proteinuria.

A total of 104 participants will be randomized in a 1:1 fashion into two treatment arms.

Randomization will be stratified by low (≥ 4 to < 8 g/day) and high proteinuria (≥ 8 g/day). This stratification will be performed to equally distribute participants at higher risk for progression to renal failure between the two study arms.

Participants randomized to the experimental arm will receive subcutaneous belimumab 400 mg (two 200 mg injections) once weekly from weeks 0-3, and then 200 mg once weekly from weeks 4-51. This dosing regimen is based on the recommended dosing of subcutaneous belimumab for lupus nephritis. Participants randomized to the comparator arm will receive subcutaneous belimumab placebo according to the same dose and schedule.

Participants in both arms will receive rituximab 1000 mg IV at weeks 4 and 6.

At week 30, participants will be assessed for a response to study treatment. Participants who meet at least two of the following three criteria at week 30 will be considered to have an inadequate response to study treatment and, defined as fulfilling at least two of the following three criteria at week 30, will receive a second course of rituximab (defined as 1000 mg IV given at weeks 34 and 36):

• Anti-PLA2R levels is ≥ 25% of baseline
• Proteinuria is ≥ 50% of baseline
• Serum albumin is < 2.8 g/dL

After the 52 week treatment period, all participants will be followed on no study medication with assessment of the primary endpoint (complete remission) at week 104.

The primary endpoint will be assessed at week 104 because the proteinuric response to treatment is known to lag behind the active treatment period and is recommended to be assessed at least 18 months after the initiation of therapy. There will be a tolerance endpoint at week 156 to determine if treatment with belimumab with rituximab results in a more durable remission compared to rituximab alone, and to assess the rate of relapse after having achieved complete or partial remission.

• Study Type: Interventional
• Enrollment (Estimated): 124
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • British Columbia
    • Vancouver, British Columbia, Canada, V5T3A5
      • The University of British Columbia: Division of Nephrology
  • Ontario
    • Toronto, Ontario, Canada, M4G3E8
      • University of Toronto, Sunnybrook Health Sciences Centre: Nephrology
    • Toronto, Ontario, Canada, M5G 2N2
      • University of Toronto, University Health Network: Nephrology
• United States
  • Alabama
    • Birmingham, Alabama, United States, 35294
      • University of Alabama at Birmingham School of Medicine: Division of Nephrology
  • California
    • San Francisco, California, United States, 94146
      • University of California San Francisco
    • Stanford, California, United States, 94305
      • Stanford University School of Medicine: Division of Nephrology
    • Torrance, California, United States, 90502
      • The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center:Division of Nephrology and Hypertension
  • Florida
    • Jacksonville, Florida, United States, 32224
      • Mayo Clinic Jacksonville: Department of Nephrology and Hypertension
    • Miami, Florida, United States, 33136
      • University of Miami Miller School of Medicine, Div of Nephrology
  • Maryland
    • Baltimore, Maryland, United States, 21287
      • Johns Hopkins
    • Bethesda, Maryland, United States, 20892
      • National Institutes of Health Clinical Center
  • Massachusetts
    • Boston, Massachusetts, United States, 02118
      • Boston Medical Center: Renal Medicine
  • Minnesota
    • Minneapolis, Minnesota, United States, 55455
      • University of Minnesota Health Clinical Research Unit
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic Rochester: Department of Nephrology and Hypertension
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University in St. Louis
  • Nebraska
    • Omaha, Nebraska, United States, 68198
      • University of Nebraska
  • New York
    • New York, New York, United States, 10032
      • Columbia University Medical Center: Division of Nephrology
  • North Carolina
    • Chapel Hill, North Carolina, United States, 27599-
      • University of North Carolina School of Medicine: Division of Nephrology and Hypertension, Kidney Center
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Cleveland Clinic
    • Columbus, Ohio, United States, 43210
      • Ohio State University Wexner Medical Center: Division of Nephrology
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania: Department of Medicine: Renal-Electrolyte and Hypertension Division
  • Tennessee
    • Nashville, Tennessee, United States, 37232
      • Vanderbilt University Medical Center: Division of Nephrology and Hypertension
  • Washington
    • Spokane, Washington, United States, 99204
      • Providence Medical Research Center, Providence Health Care: Nephrology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Subjects must meet all of the following criteria to be eligible for this study-

1. Age 18 to 75 years inclusive

2. Diagnosis of one of the following:

   1. Primary MN confirmed by a kidney biopsy within the past 5 years
   2. Primary MN that is relapsing following a CR (Section 3.3.1) or PR (Section 3.3.2), confirmed by a kidney biopsy within the past 7 years
   3. Nephrotic syndrome with eGFR > 60 mL/min/1.73m2 and no history of immunosuppressant treatment (e.g. glucocorticoids, cyclophosphamide, cyclosporine A, tacrolimus, B-cell depleting agent) for nephrotic syndrome, and without evidence of a secondary cause of nephrotic syndrome
   4. Nephrotic syndrome and a contraindication to kidney biopsy (e.g., anticoagulation, solitary kidney, body habitus that increases the risk of biopsy, or other contraindication in the opinion of the investigator), and without evidence of a secondary cause of nephrotic syndrome
3. Serum anti-PLA2R positive
4. eGFR ≥ 30 mL/min/1.73m2 while on maximally tolerated RAS blockade

5. Proteinuria:

   1. ≥ 4 and < 8 g/day that has persisted for at least the previous 3 months while on maximally tolerated RAS blockade. Documentation of persistent proteinuria may be from a 24-hour collection or calculated from a spot urine collection. Or,
   2. ≥ 8 g/day while on maximally tolerated RAS blockade

6. Blood pressure while on maximally tolerated RAS blockade:

   1. Systolic blood pressure ≤ 140 mmHg
   2. Diastolic blood pressure ≤ 90 mmHg
7. SARS-CoV-2 vaccination according to the current Centers for Disease Control and Prevention (CDC) Advisory Committee on Immunization Practices (ACIP) recommendations. The last SARS-CoV-2 vaccine dose must have been administered at least 14 days prior the initiation of the study drug (Visit 0).

Exclusion Criteria:

Subjects meeting any of the following criteria will not be eligible for this study-

1. Secondary cause of MN (e.g., SLE, drug, infection, malignancy) suggested by review of the patient's medical history and/or clinical presentation
2. Rituximab use within the previous 12 months

3. Rituximab use > 12 months ago:

   1. With an undetectable CD19 B cell count, or
   2. Did not result in a CR (Section 3.3.1) or PR (Section 3.3.2) with rituximab treatment alone (e.g., without other immunosuppressive or immunomodulatory therapy)
4. Use of anti-B cell therapy other than rituximab within the previous 12 months (or 5 half-lives, whichever is greater)
5. Cyclophosphamide use within the past 3 months
6. Use of other immunosuppressive medications such as cyclosporine or tacrolimus within the past 30 days
7. Use of systemic corticosteroids within the past 30 days
8. Use of any biologic investigational agent (defined as any drug not approved for sale in the country it is used) in the previous 12 months
9. Use of any non-biologic investigational agent in the past 30 days (or 5 half-lives, whichever is greater)
10. Poorly controlled diabetes mellitus defined as hemoglobin A1c (HbA1c) ≥ 9.0%

11. Patients with diabetic glomerulopathy on renal biopsy that is:

    1. Greater than Class I diabetic glomerulopathy, or
    2. Class I diabetic glomerulopathy with a history of poor diabetic control (e.g., HbA1c ≥ 9.0%) since time of biopsy
12. Unstable kidney function defined as > 20% decrease in eGFR during the previous 3 months due to primary MN, as determined by the site investigator in consultation with the protocol chair
13. Decrease in proteinuria by 50% or more during the previous 12 months
14. WBC count < 3.0 x 103/μl
15. Absolute neutrophil count < 1.5 x 103/μl
16. Moderately severe anemia (hemoglobin < 9 g/dL)
17. History of primary immunodeficiency
18. Serum IgA < 10 mg/dL
19. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ 2x the upper limit of normal (ULN)
20. Positive HIV serology
21. Positive HCV serology, unless treated with anti-viral therapy with achievement of a sustained virologic response (undetectable viral load 24 weeks after cessation of therapy)
22. Evidence of current or prior infection with hepatitis B, as indicated by positive HBsAg or positive HBcAb
23. Positive QuantiFERON - TB Gold test results. PPD tuberculin test may be substituted for QuantiFERON - TB Gold test
24. History of lung disease with FVC < 70% predicted, DLCO < 70% predicted, or requiring supplemental oxygen
25. History of malignant neoplasm within the last 5 years except for basal cell or squamous cell carcinoma of the skin treated with local resection only or carcinoma in situ of the uterine cervix treated locally and with no evidence of metastatic disease for 3 years
26. Absence of individualized, age-appropriate cancer screening
27. Women of child-bearing potential who are pregnant, nursing, or unwilling to be sexually inactive or use FDA-approved contraception until week 104
28. Acute or chronic infection, including current use of suppressive therapy for chronic infection, hospitalization for treatment of infection in the past 60 days, or parenteral anti-microbial (including anti-bacterial, anti-viral, or anti-fungal agents) use in the past 60 days for infection
29. History of an anaphylactic reaction or known sensitivity or intolerance to parenteral administration of contrast agents, human or murine proteins, or monoclonal antibodies, including rituximab or belimumab
30. Evidence of serious suicide risk including any history of suicidal behavior in the last 6 months and/or any suicidal ideation in the last 2 months, or who in the investigator's judgment, poses a significant suicide risk
31. Evidence of current drug or alcohol abuse or dependence, or a history of drug or alcohol abuse or dependence in the past 12 months
32. Vaccination with a live vaccine within the past 30 days
33. Other diseases or conditions or other clinically significant abnormal laboratory value which in the opinion of the investigator would put the patient at risk or confound the results of the study
34. Inability to comply with study and follow-up procedures

Study Plan

How is the study designed?

Design Details

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

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part A: Low Proteinuria Group - Belimumab and Rituximab; Open-label pharmacokinetics (PK) phase. Participants with low proteinuria classification will receive belimumab weekly subcutaneous injections (52 doses administered Week 0 to Week 51) and rituximab infusions at Weeks 4 and 6. Low proteinuria classification: The excretion of ≥4 to <8 g/day of protein by the kidneys in adults. (Normal in adults: 0.15 g/day).	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Belimumab; Belimumab is a recombinant, human, IgG1λ monoclonal antibody. Belimumab will be provided as a 200 mg sterile, liquid product in a prefilled syringe. Each syringe contains 1.0 mL of 200 mg/mL belimumab. Each syringe will be a single use. Standard Weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Benlysta®
Experimental: Part A :High Proteinuria Group - Belimumab and Rituximab; Open-label pharmacokinetics (PK) phase. Participants with high proteinuria classification will receive belimumab weekly subcutaneous injections (52 doses administered Week 0 to Week 51) and rituximab infusions at Weeks 4 and 6. High proteinuria classification: The excretion of ≥8 g/day of protein by the kidneys in adults. (Normal in adults: 0.15 g/day).	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Belimumab; Belimumab is a recombinant, human, IgG1λ monoclonal antibody. Belimumab will be provided as a 200 mg sterile, liquid product in a prefilled syringe. Each syringe contains 1.0 mL of 200 mg/mL belimumab. Each syringe will be a single use. Standard Weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Benlysta®
Experimental: Part B: Low Proteinuria Group - Belimumab and Rituximab; Participants in the low proteinuria classification stratification, based upon Part A, and randomized to this arm, will receive subcutaneous belimumab 400 mg (two 200 mg injections) once weekly from weeks 0-3, and then 200 mg once weekly from weeks 4-51. Participants will receive rituximab infusions at Weeks 4 and 6. At week 30, participants will be assessed for a response to study treatment. Participants who meet at least two out of the following three criteria at week 30 will be considered to have an inadequate response to study treatment and receive a second course of rituximab (defined as 1000 mg IV given at weeks 34 and 36): Anti-PLA2R level is ≥ 25% of baseline; Proteinuria is ≥ 50% of baseline; Serum albumin is < 2.8 g/dL	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Belimumab; Belimumab is a recombinant, human, IgG1λ monoclonal antibody. Belimumab will be provided as a 200 mg sterile, liquid product in a prefilled syringe. Each syringe contains 1.0 mL of 200 mg/mL belimumab. Each syringe will be a single use. Standard Weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Benlysta®
Placebo Comparator: Part B: Low Proteinuria Group - Placebo and Rituximab; Participants in the low proteinuria classification stratification, based upon Part A, and randomized to this arm, will receive subcutaneous belimumab placebo 400 mg (two 200 mg injections) once weekly from weeks 0-3, and then 200 mg once weekly from weeks 4-51. Participants will receive rituximab infusions at Weeks 4 and 6. At week 30, participants will be assessed for a response to study treatment. Participants who meet at least two out of the following three criteria at week 30 will be considered to have an inadequate response to study treatment and receive a second course of rituximab (defined as 1000 mg IV given at weeks 34 and 36): Anti-PLA2R level is ≥ 25% of baseline; Proteinuria is ≥ 50% of baseline; Serum albumin is < 2.8 g/dL	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Placebo for Belimumab; The placebo control will be provided as a sterile liquid product in a prefilled syringe. Each syringe will be of a single use. Standard weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Belimumab placebo
Experimental: Part B :High Proteinuria Group - Belimumab and Rituximab; Participants in the high proteinuria classification stratification, based upon Part A, and randomized to this arm, will receive subcutaneous belimumab 400 mg (two 200 mg injections) once weekly from weeks 0-3, and then 200 mg once weekly from weeks 4-51. Participants will receive rituximab infusions at Weeks 4 and 6. At week 30, participants will be assessed for a response to study treatment. Participants who meet at least two out of the following three criteria at week 30 will be considered to have an inadequate response to study treatment and receive a second course of rituximab (defined as 1000 mg IV given at weeks 34 and 36): Anti-PLA2R level is ≥ 25% of baseline; Proteinuria is ≥ 50% of baseline; Serum albumin is < 2.8 g/dL	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Belimumab; Belimumab is a recombinant, human, IgG1λ monoclonal antibody. Belimumab will be provided as a 200 mg sterile, liquid product in a prefilled syringe. Each syringe contains 1.0 mL of 200 mg/mL belimumab. Each syringe will be a single use. Standard Weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Benlysta®
Placebo Comparator: Part A :High Proteinuria Group - Placebo and Rituximab; Participants in the high proteinuria classification stratification, based upon Part A, and randomized to this arm, will receive belimumab placebo weekly subcutaneous injections (52 doses administered Week 0 to Week 51) and rituximab infusions at Weeks 4 and 6.	Drug: Rituximab; Rituximab is a monoclonal antibody with specificity for CD20, a transmembrane protein expressed on B cells from the pre-B to memory cell development stages. Rituximab is supplied at a concentration of 10 mg/mL in either 100 mg/10 mL or 500 mg/50 mL single-use vials for infusion. It is a clear, colorless liquid. Dose: 1000 mg intravenously (IV), Week 4 and -6.; Other Names: Rituxan®; Drug: Placebo for Belimumab; The placebo control will be provided as a sterile liquid product in a prefilled syringe. Each syringe will be of a single use. Standard weekly dose: Part A: 200 mg. administered subcutaneously. Part B: 400 mg (two 200 mg injections) from weeks 0-3, and then 200 mg from weeks 4-51, administered subcutaneously.; Other Names: Belimumab placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Participants in Complete Remission (CR) at Week 104: By Treatment Group	Defined as proteinuria of ≤ 0.3 g/day with a < 20% decrease in estimated glomerular filtration rate (eGFR) from baseline.	Week 104

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of Participants in Complete Remission (CR) at Week 52 and Week 156: By Treatment Group	Defined as proteinuria of ≤ 0.3 g/day with a < 20% decrease in estimated glomerular filtration rate (eGFR) from baseline.	Week 52, Week 156
Proportion of Participants in Partial Remission (PR) at Week 52, Week 104 and Week 156: By Treatment Group	Defined as a 50% or greater decrease in proteinuria compared to baseline and proteinuria <3.5 g/day with a < 20% decrease in eGFR from baseline.	Week 52, Week 104, Week 156
Proportion of Participants in Complete or Partial Remission at Week 52, Week 104, Week 156: By Treatment Group	Those who fulfill criteria for either complete or partial remission, as defined in prior outcome measures.	Week 52, Week 104, Week 156
Time to Relapse for Participants who Achieved Complete Remission (CR) or Partial Remission (PR): By Treatment Group	Relapse is defined as a return of proteinuria ≥ 3.5 g/day after: Achieving a CR, or; Achieving and maintaining a PR for at least 12 weeks. The first timepoint at which a participant achieves CR or PR will be taken defined as Time 0. Participants will be followed from Time 0 to the first evaluation at which the participant fulfills the definition for relapse.	Up to 156 Weeks (3 Years)
Level of Proteinuria at Week 52, Week 104 and Week 156: By Treatment Group	Method of assessment: 24 hour urine collection for quantitation of protein in the urine.	Week 52, Week 104, Week 156
Proportion of Participants in Complete Remission (CR) and Anti-PLA2R Negative: By Treatment Group	CR as defined per protocol. Antibodies to the phospholipase A2 receptor 1 (Anti-PLA2R antibodies) are a correlate ot primary MN disease activity.	Week 104
Proportion of Participants in Partial Remission (PR) and Anti-PLA2R Negative: By Treatment Group	PR as defined per protocol and in prior outcome measures. Antibodies to the phospholipase A2 receptor 1 (Anti-PLA2R antibodies) are a correlate ot primary MN disease activity.	Week 104
Proportion of Participants Who are Anti-PLA2R Negative: By Treatment Group	Antibodies to the phospholipase A2 receptor 1 (Anti-PLA2R antibodies) are a correlate ot primary MN disease activity.	Week 52, Week104, Week 156
Incidence of Adverse Events (AEs): By Treatment Group	An AE is any untoward or unfavorable medical occurrence associated with the participant's participation in the research, whether or not considered related to the participant's participation in the research. For purposes of this study, neither B cell depletion nor proteinuria will be classified as an AE.	Week 0 to Week 52
Incidence of Grade 3 or Higher Infectious Adverse Events (AEs): By Treatment Group	Reference: NCI-CTCAE manual titled, National Cancer Institute (NCI)s Common Terminology Criteria for Adverse Events Version 5.0 (published November 27, 2017).	Week 0 to Week 52
Incidence of Arterial Thromboembolic Events: By Treatment Group	Peripheral vascular embolism, mesenteric infarct, or myocardial infarction.	Week 0 to Week 52
Incidence of Venous Thromboembolic Events: By Treatment Group	Venous thromboembolic event (VTE) is defined as a symptomatic deep vein thrombosis (DVT): the formation of a blood clot in a deep vein, detected by systematic compression ultrasonography, symptomatic DVT, or symptomatic fatal or non-fatal pulmonary embolism (PE). An embolism is a clot in the blood that forms and blocks a blood vessel. A pulmonary embolism is a blood clot that has travelled from elsewhere in the body through the blood stream to block the main artery of the lung or one of its branches.	Week 0 to Week 52
Kidney Disease Quality of Life (KDQOL-36) Mean Scale Scores at Baseline, Week 52, Week 104 and Week 156: By Treatment Group	A Quality of life (QOL) measure using the Kidney Disease Quality of Life-36 (KDQOL-36) survey, a kidney-disease-specific quality of life instrument that assesses five domains: general physical health, mental health, disease burden, disease symptoms, and disease effects. For all KDQOL scales, a higher score indicates better quality of life. All domain scales can range from 0-100.	Week 52, Week 104, Week 156
Belimumab Exposure After the First 4 Doses of Belimumab	Pharmacokinetics (PK) Assay -Applicable to Part A of the Study. Belimumab exposure will be assessed using the observed belimumab trough levels (C_min) after 4 weeks (i.e., Week 0, Week 1, Week 2 and Week 3) of subcutaneous dosing. Analysis will be begin after all participants in Part A have reached week 4.	Week 0, Week 1, Week 2, Week 3
Proportion of participants meeting criteria for a second course of rituximab at week 30		Week 30

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
EXPLORATORY: Belimumab Levels at Week 4, Week 12, Week 24, Week 36 and Week 52	Exploratory analyses will be performed combining participant data from Part A with the subgroup of Part B participants treated with belimumab.	Week 4, Week 12, Week 24, Week 36, Week 52

Collaborators and Investigators

• Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
• Collaborators: GlaxoSmithKline; PPD; Rho Federal Systems Division, Inc.; Immune Tolerance Network (ITN)
• Investigators: Study Chair: Patrick Nachman, M.D., University of Minnesota, Department of Medicine, Division of Renal Diseases and Hypertension; Study Chair: Iñaki Sanz, M.D., Emory University, Department of Medicine, Division of Rheumatology

Publications and helpful links

General Publications

• Ayoub I, Nachman PH. Advances in ANCA-associated vasculitis and lupus nephritis. Nat Rev Nephrol. 2021 Feb;17(2):89-90. doi: 10.1038/s41581-020-00388-x. No abstract available.

Helpful Links

• Immune Tolerance Network (ITN)
• Visit this ITN Study website for more information

Study record dates

Study Major Dates

• Study Start (Actual): March 6, 2020
• Primary Completion (Estimated): March 1, 2029
• Study Completion (Estimated): March 1, 2030

Study Registration Dates

• First Submitted: May 13, 2019
• First Submitted That Met QC Criteria: May 13, 2019
• First Posted (Actual): May 14, 2019

Study Record Updates

• Last Update Posted (Actual): April 5, 2024
• Last Update Submitted That Met QC Criteria: April 4, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: nephrotic syndrome; Primary Membranous Nephropathy; Pharmacokinetics (PK) Analysis; Double-Blind (Masked), Placebo-Controlled Clinical Trial; Co-administered belimumab and rituximab
• Additional Relevant MeSH Terms: Immune System Diseases; Autoimmune Diseases; Urologic Diseases; Nephritis; Glomerulonephritis; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Kidney Diseases; Nephrotic Syndrome; Nephrosis; Glomerulonephritis, Membranous; Physiological Effects of Drugs; Antirheumatic Agents; Antineoplastic Agents; Immunosuppressive Agents; Immunologic Factors; Antineoplastic Agents, Immunological; Rituximab; Belimumab
• Other Study ID Numbers: DAIT ITN080AI; NIAID CRMS ID#:38478 (Other Identifier: DAIT NIAID)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The plan is to share data upon completion of the study in: Immunology Database and Analysis Portal (ImmPort), a long-term archive of clinical and mechanistic data from DAIT-funded grants and contracts.
• IPD Sharing Time Frame: On average, within 24 months after database lock for the trial.
• IPD Sharing Access Criteria: Open access.

Drug and device information, study documents

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