Decision of Data Safety Monitoring Board

Idiopathic Nephrotic Syndrome (INS) is the first glomerulopathy in children and 60% of the patients develop Steroid-Dependant Nephrotic Syndrome (SDNS). Recently, rituximab (RTX), a humanized anti-CD20 antibody depleting B cells demonstrated the ability to increase relapse free survival and to decrease the number of relapse and the need of other immunosuppressive drugs. However, the remission rate after 2 years is only 30 to 40%.

The aim of the study is to study the ability of intravenous Immunoglobulin to improve remission rate in SDNS when added associated with Rituximab compared to a treatment by Rituximab alone.

Idiopathic Nephrotic Syndrome (INS) is the first glomerulopathy in children and 60% of the patients develop Steroid-Dependant Nephrotic Syndrome (SDNS). Depleting B cells demonstrated the ability to increase relapse free survival and to decrease the number of relapse and the need of other immunosuppressive drugs. However, the remission rate after 2 years is only 30 to 40%.

The aim of the study is to study the ability of intravenous Immunoglobulin to improve remission rate in SDNS when added associated with Rituximab compared to a treatment by Rituximab alone.

Inclusion Criteria:

• Childhood onset nephrotic syndrome (first flair <18 years)

• ≥ 2 years old at inclusion

• Steroid-dependent:

  • Patient with at least 2 relapses confirmed during the decay of corticosteroids or within 2 weeks following steroids discontinuation.
  • Patient with at least 2 relapses including one under steroidsparing agent (MMF, Calcineurin inhibitors, cyclophosphamide, Levamisole) or within 6 months of treatment withdrawal.

• or with frequent relapses:

  · 2 or more relapses within 6 months after initial remission or 4 or more relapses within any 12-month period.

• with a relapse within 3 months prior to inclusion

• In remission: Protein-over-creatinine ratio ≤ 0.2g/g (≤ 0.02g/mmol)

Exclusion Criteria:

• Patients with steroid-resistant nephrotic syndrome;
• Patients with genetic nephrotic syndrome;
• Patients previously treated with rituximab;
• Patients with no affiliation to a social security scheme (beneficiary or legal);
• Prior Hepatitis B, Hepatitis C or HIV infection;
• Pregnancy or breastfeeding.
• Patients with hyperprolinaemia,
• Known hypersensitivity to one of the study medication,
• Scheduled and not postponable injection of live attenuated vaccine
• Protected adults
• Patients with neutrophils < 1.5 G/L and/or platelets < 75 G/L

No masking