Author Of 1 Presentation
P0863 - Discontinuation and dose reduction of rituximab in patients with relapsing remitting multiple sclerosis (ID 1103)
Abstract
Background
In relapsing remitting multiple sclerosis (RRMS) inflammatory disease activity decreases with higher age and longer disease duration. The disease modifying treatments available today are aimed at suppressing inflammatory activity and younger age and higher disease activity are associated with larger relative treatment benefits.
At the University Hospital of Umeå, in Västerbotten county, Sweden, >90% of all patients with RRMS are treated with the monoclonal anti-CD20 B-cell depleting antibody rituximab (RTX). In a placebo-controlled phase II study, RTX have displayed high efficacy in suppressing inflammatory disease activity and in several retrospective observational studies RTX shows high effectiveness compared to other disease modifying therapies commonly used. However, there are limited data on disease activity after discontinuation of treatment with RTX.
Objectives
The primary objective is to evaluate effects on inflammatory disease activity (defined as clinical relapses, new cerebral T2 lesions and/or contrast enhancing lesions on MRI) after discontinuation of treatment with RTX in patients with RRMS or possible MS. The secondary objective is to evaluate the effects on inflammatory disease activity after dose reduction to an average of <1000 mg/year in the same patient group.
Methods
In this retrospective observational study data is collected from the Swedish MS registry and medical records. We include all RRMS and possible MS patients ever treated with ≥2 doses and a total of ≥1000 mg of RTX at the University Hospital of Umeå who either; (1) have discontinued treatment at any time (i.e. ≥18 months since last infusion) or (2) have reduced the treatment dose to a mean of <1000 mg RTX yearly.
Results
Preliminary data indicate that 228 patients meet the inclusion criteria. 102 patients (45%) have discontinued treatment and 206 patients (90%) have reduced the dose to <1000 mg/year at some point during the observation period. Further data analysis will include a comparison of annualized relapse rates and inflammatory disease activity on MRI between time on-treatment, time off-treatment and/or time on low-dose treatment.
Conclusions
This study will provide real-world data that may guide clinicians in future treatment decisions for RRMS patients treated with RTX.