Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


The Belgian MIRA (MabThera in Rheumatoid Arthritis) Registry: Clues for the Optimization of Rituximab Treatment Strategies.

Vander Cruyssen2,  Bert, Durez1,  Patrick, Westhovens5,  Rene, Hoffman3,  Ilse, Kaiser4,  M. J., De Keyser,  Filip

Cliniques Universitaires Saint-Luc, Brussels
Ghent University Hosptial
GZA St-Augustinus Hospital Antwerp, Belgium
University Hospital Liege, Liege, Belgium
University Hospitals KULeuven, Leuven, Belgium

Background:

The Belgian MIRA registry aims to record safety and efficacy data of rituximab treatment. In Belgium, RA patients are eligible for treatment with rituximab if they failed at least 1 anti-TNF and have a baseline DAS28 > 3.7. From week 24 on, patients can be retreated if they have a moderate or good EULAR response at week 16, and a current DAS28 score of at least 3.2.

Methods:

All Belgian rheumatologists could participate in the study. Patients entered the registry as from November 2006 and the entry is still open. All patients were treated with 2 infusions per course of rituximab (2 × 1000 mg week 0 and 2) in combination with 100 mg of methylprednisolone and MTX. Baseline patient's characteristics were recorded as well as DAS28-variables every 2 months.

Results:

By mid may 2010, 497 patients had entered the registry with a mean follow-up time of 84 weeks. Patients (mean age of 59 years, 77 % female) had a mean disease duration of 12 years.

Rituximab therapy decreased the overall mean disease activity from DAS28-ESR 5.9 (SE = 0.1) at baseline to 4.1 (SE = 0.1) at week 16. 83% of patients fulfilled the EULAR good or moderate response criteria. Further decrease of DAS was observed at the end of year 1 and year 2 with a mean DAS28-ESR of 4.0 (SE = 0.2) and 3.7 (SE = 0.2) at these respective time points.

342 and 188 patients received a 2nd and 3rd course of rituximab respectively. The median time to retreatment was 32 weeks after the first course.

At the start of each treatment course, the DAS28-ESR values were lower compared to values at the start of the previous treatment course. The values reached a minimum at week 16 of each respective treatment course, and then increased slightly, until the start of the following treatment course. Paired analysis of DAS28 scores 6 months after the first and second course suggests that lower DAS scores are obtained after the second course (mean diff =-0.6, SE =0.2, p <0.001).

This further decrease of DAS28 scores between the first and second course was especially seen in those patients who did not flare (increase of DAS28>1.2) between week 24 and their second course (mean diff =-1.1, SE = 0.2 vs. mean diff -0.08, SE = 0.4, p = 0.002).

85 patients discontinued treatment: 62 stopped due to inefficacy and 18 stopped due to safety issues (infusion reactions in 6 patients, infections in 5, other reasons in 7 patients). 2 Patient died. Only 33 patients were lost to follow-up.

Conclusions:

The efficacy of rituximab in refractory RA patients is confirmed in this daily practice cohort. DAS28 response was observed in the large majority of our cohort and a sustained DAS 28 decrease was observed during the following course, especially in patients who didn't show an obvious flare. These elements suggest that treatment of RA patients with rituximab could be optimized by earlier retreatment in patients who developed flares.

To cite this abstract, please use the following information:
Vander Cruyssen, Bert, Durez, Patrick, Westhovens, Rene, Hoffman, Ilse, Kaiser, M. J., De Keyser, Filip; The Belgian MIRA (MabThera in Rheumatoid Arthritis) Registry: Clues for the Optimization of Rituximab Treatment Strategies. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :340
DOI: 10.1002/art.28109

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