Abstract: TH-PO143

Low Dose Rituximab Is Non-Inferior to Higher or Multiple Dose Schedules in the Treatment of Steroid Sensitive, Frequently Relapsing Nephrotic Syndrome in Children

Session Information

Category: Glomerular

  • 1005 Clinical Glomerular Disorders

Authors

  • Reynolds, Ben C, Royal Hospital for Children, Glasgow, Glasgow, United Kingdom
  • Dalrymple, Rebecca Amy, Greater Glasgow and Clyde NHS, Glasgow, United Kingdom
  • Maxted, Andrew P, Nottingham Children''s Renal and Urology Unit, Nottingham, United Kingdom
  • Chisholm, Denise, Nottingham Children''s Renal and Urology Unit, Nottingham, United Kingdom
  • Mccoll, John Hope, University of Glasgow, Glasgow, United Kingdom
  • Tse, Yincent, Great North Children's Hospital, Newcastle upon Tyne, United Kingdom
  • Christian, Martin, NHS, Nottingham, United Kingdom
Background

Rituximab is an effective treatment for children with steroid dependent or frequently relapsing nephrotic syndrome. Dosing schedules vary between centres and are based on anecdotal evidence and non randomised controlled data. We hypothesised that a single low dose of 375mg/m2 would be non-inferior to higher or multiple doses, in maintaining remission and time to B-cell reconstitution.

Methods

This was a retrospective, observational cohort study of children from three paediatric nephrology centres in the United Kingdom. Children with steroid sensitive, frequently relapsing nephrotic syndrome who received Rituximab since January 2007 were included. Data were extracted from clinical records on the dates of diagnosis, treatment and relapses; lymphocyte subset profiling pre-and post-rituximab administration; and the use of concomitant immunosuppression. The primary outcome was an absence of clinically confirmed relapse 12 months after Rituximab administration. Secondary outcomes were median time to relapse, probability of being relapse free at 6 and 24 months and time to reconstitution of CD19+ B cells (CD 19+ B cells >0.2 x109).

Results

60 patients received 143 courses of Rituximab. Patients were grouped according to the dose of Rituximab received; those in group 1 (15 courses) received a higher total dose of 1.5g/m2, group 2 (25 doses) received an intermediate dose between 750mg/m2 – 1g/m2, and group 3 (103 courses) received our current low dose regimen of a single dose of 375mg/m2. There was no difference in event-free survival at 6, 12, or 24 months between groups. Of those who relapsed, the median time to relapse was not significantly different between the high and low dose groups, 317 days in group one and 299 days in group three. The median time to reconstitution of B-cells was not significantly different between groups at 175, 226 and 196 days for groups 1, 2 and 3 respectively.

Conclusion

We conclude that usage of a single low dosage of Rituximab in the management of frequently relapsing nephrotic syndrome does not affect the probability of relapse at 6 and 12 months, or the time to B-cell reconstitution in our cohort of patients.