ESPN 51th Annual Meeting

ESPN 2018


 
Effect of different Rituximab regimens on B cell depletion and time to relapse in children with steroid-dependant nephrotic syndrome
JULIEN HOGAN 1 CLAIRE DOSSIER 1 THERESA KWON 1 MARIE-ALICE MACHER 1 ANNE MAISIN 1 ANNE COUDERC 1 OLIVIER NIEL 1 VERONIQUE BAUDOUIN 1 GEORGES DESCHENES 1

1- PEDIATRIC NEPHROLOGY DEPARTMENT ROBERT DEBRE HOSPITAL, APHP, PARIS, FRANCE
 
Introduction:

 Several studies demonstrated that Rituximab (RTX) improves relapse-free survival in patients with steroid-dependant nephrotic syndrome (SDNS). However, these studies used various RTX regimens and there are few data comparing these regimens in children with SDNS. In this retrospective study, we aim at assessing the effect of three different initial RTX regimens on both the time to B cell reconstitution and to first relapse.

Material and methods:

 Sixty-one SDNS patients receiving a first course of RTX were included. Group 1 received one injection of 100mg/m2, group 2 one injection of 375mg/m2 and group 3 received two injections of 375mg/m2 at day 0 and day 7. Time to B cell reconstitution and time to first relapse and respective risk factors were studied.

Results:

Median time to B cell reconstitution was 2.5 [1.8-3.5], 5.0 [3.9-6.0] and 6.6 [4.6-7.8] months in group 1, 2 and 3, respectively. RTX regimen was associated with the time to B cell reconstitution (HRs Group 2 vs. 3: 4.07 [1.96-8.48]; Group 1 vs. 3: 11.13 [4.04-30.67]). One-year relapse-free survival was 50% [58-77], 59% [42-76] and 72% [46-87] in group 1, 2 and 3 respectively. RTX regimen was associated with the risk of relapse (HRs Group 2 vs. 3: 1.55 [0.51-4.65]; Group 1 vs. 3: 4.98 [1.15-21.60]).

Conclusions:

The initial dose of Rituximab impacts the time to B cell reconstitution and the probability of relapse. Risk of relapse is also associated with patient characteristics, suggesting that RTX regimen could be modified for each patient to balance efficacy, cost and side effects.