ESPN 51th Annual Meeting

ESPN 2018


 
Rituximab treatment in children with oncological, infectious or autoimmune diseases
ABDELJAOUAD BOALLOUCHE 1 HANNERIEKE VAN DEN HOUT 1 ELISE HUISMAN 1 SYLVIA KAMPHUIS 1 RINZE NEUTEBOOM 1 CLEMENTIEN VERMONT 1 ANDRICA DE VRIES 1 EISKE DORRESTEIJN 1

1- ERASMUS MEDICAL CENTER, ROTTERDAM, THE NETHERLANDS
 
Introduction:

In pediatric care, many oncological and autoimmune diseases are treated with rituximab. However, since its approval 20 years ago, many different rituximab dosage regimens have arisen. This study aimed to investigate the relationship between rituximab dosage regimens and the duration of B-cell depletion. This study also aimed to investigate the relationship between different regimens and the clinical response.

Material and methods:

Retrospective cohort study of patients aged 0-18 years, treated with rituximab for oncological, autoimmune or infectious diseases at the Erasmus Medical Center-Sophia Children’s Hospital between January 1st, 2006 and January 1st, 2017. Based upon the cumulative rituximab dosages, patients were divided in a low dose group (≤500mg/m2), an intermediate group (501-1250mg/m2) and a high dose group (>1250mg/m2). The duration of B-cell depletion was defined as the time until B-cell counts reached a value of  ≥1.0*109/L. Clinical response was assessed at 6 months and was classified as either good, moderate or bad.

Results:

Sixty-three patients were included in this study. In the entire group, the mean rituximab dosage was 1084mg/m2 (range=320-1724mg/m2). Rituximab dosage had an adjusted hazard ratio (aHR) of 1.00 (95% CI, 1.00-1.00; p=0.81) for B-cell repopulation for every increase of 1 mg/m2. Compared to the low dose group (n=8), the intermediate (n=30) and high dose group (n=25) had aHRs for B-cell repopulation of 0.41 (95% CI, 0.16-1.04; p=0.06) and 0.99 (95% CI, 0.41-2.37; p=0.97), respectively. Good responses in the low, intermediate and high dose group were seen in 37.5%, 46.7% and 36%, respectively. The adjusted odds ratios for improvement of disease activity were 1.82 (95% CI, 0.41-8.19, p=0.43) and 1.06 (95% CI, 0.22-5.05, p=0.94) for the intermediate and the highest group compared to the lowest group.

Conclusions:

This study did not find any difference between different rituximab dosage regimens and the duration of B-cell depletion or disease activity at 6 months after rituximab.