ESPN 50th Annual Meeting

ESPN 2017


 
A single low dose schedule of Rituximab is non-inferior to high dose and multiple dose schedules in the treatment of steroid sensitive frequently relapsing nephrotic syndrome
ANDREW MAXTED 1 REBECCA DALRYMPLE 2 DENISE CHISHOLM 3 JOHN MCCOLL 4 URSULA MONACHAN 2 YINCENT TSE 3 MARTIN CHRISTIAN 1 BEN REYNOLDS 2

1- NOTTINGHAM CHILDREN’S HOSPITAL, RENAL AND UROLOGY UNIT
2- ROYAL HOSPITAL FOR CHILDREN, GLASGOW
3- GREAT NORTH CHILDRENS HOSPITAL, NEWCASTLE
4- SCHOOL OF MATHEMATICS AND STATISTICS, UNIVERSITY OF GLASGOW
 
Introduction:

Rituximab is an emerging and effective treatment for children with steroid dependent or frequently relapsing nephrotic syndrome. The optimum dosing schedule for Rituximab has not been established. We hypothesised that a single low dose of 375mg/m2 would be non-inferior to higher or multiple doses in reducing the frequency of disease relapse and time to B-cell reconstitution.

Material and methods:

This was a multicentre, retrospective, observational cohort study of children with a diagnosis of steroid sensitive frequently relapsing nephrotic syndrome. Data were extracted from clinical records on the dates of diagnosis, treatment and relapses; the use of concomitant immunosuppression; and lymphocyte subset profiling pre-and post-rituximab administration. The primary outcome was an absence of clinically confirmed relapse 12 months following Rituximab administration. Secondary outcomes were median time to relapse, probability of being relapse free at 6 and 24 months, time to reconstitution of CD19+ B cells and the introduction of additional or ongoing immunosuppression. 

 

Results:

60 patients received 143 courses of Rituximab. Patients in group 1 received a higher total dose of 1.5g/m2, group 2 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 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.

Conclusions:

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