Background The recommended therapeutic regime for Rituximab (RTX) in Rheumatoid Arthritis (RA), according to prescribing information, includes two 1000-milligram infusions given two weeks apart, every 6 months. However, this is often not the case in clinical practice, since both consensus documents and information from clinical trials consider other alternatives.
Objectives Our objective in this study was to analyze the regime of use of RTX in RA in daily clinical practice.
Methods This is a retrospective study that includes patients treated with RTX between 1998 and 2013 in a single university hospital. We reviewed medical records and collected demographic data, number of cycles, doses and intervals of RTX administered to the patients, response duration, as well as frequency and reasons of treatment discontinuation. Descriptive analysis was performed using the statistical package Stata v. 12.
Results Ninety-three patients were studied, of which 83% were women. Median age at disease onset was 51 years with an interquartile range (IQR) of 39 to 60 years. Median age at the start of treatment with RTX was 60 [IQR: 51-70] years. Out of the 93 patients, 11 had negative rheumatoid factor. The number of cycles of RTX administered to each patient ranged from one to nine. Treatment was discontinued in 33% of the patients. The reasons for discontinuation were inefficacy (16%), adverse effects (7%) and others (10%). RTX was most commonly withdrawn during the first two cycles. The main data related to use of RTX in our study are summarized in the following table.
Response duration in males tended to be longer [12 months; IQR: 8-13] than in females [10 months; IQR: 7-12], but this didn't reach statistical significance (p=0'11, Mann-Whitney's test). Longer response duration was observed in patients with a longer RA history (r =0.24, P=0.001, Pearson's test). RTX dose per cycle did not modify the response duration (1 vs 2 grams, 9.5 and 10 months respectively).
Conclusions Our data show that, in daily clinical practice, RTX is more frequently used on demand, tending to abandon the fixed regime of 2 grams every six months. In addition, we observe a tendency to an increased use of 1 gram cycles with time. This results in cost savings without apparent decrease in healthcare quality.
Martín Mola et al. Grupo de Expertos en Rituximab. Reumatol Clin. 2011;7:30-44
Disclosure of Interest None declared