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.


Efficacy and Tolerance of Rituximab in Refractory Idiopathic Inflammatory Myopathy. Data of the AIR Registry.

Couderc3,  Marion, Gottenberg12,  Jacques E., Mariette2,  Xavier, Hachulla9,  Eric, Sibilia11,  Jean, Fain6,  Olivier, Hot8,  Arnaud

Aulnay Hospital, Carrieres Sur Seine, France
Paris Hospital
Strasbourg Hospital, Strasbourg, France
Strasbourg Hospitals, Strasbourg, France
Toulouse Hopsital
Toulouse Hospital
Bicetre Hospital/Paris Univ, Le Kremlin Bicetre, France
Clermont-Ferrand Hospital
Groupe Hospitalier Pellegrin, Bordeaux, France
Hospital Cochin, Paris, France
Jean Verdier Hospital, Paris University
L'Archet Hospital (University), Nice, France
Lyon Hospital
National Scleroderma Centre, Lille Cedex, France

Objective:

To assess the efficacy and tolerance of Rituximab (RTX) in patients with refractory idiopathic inflammatory myopathies.

Methods:

Adult patients from the Auto-Immunity and Rituximab (AIR) french registry treated by RTX for polymyositis (PM), dermatomyositis (DM) or antisynthetase syndrome (AS) were prospectively included. Efficacy was evaluated on the basis of CPK level, daily corticosteroid dose (CS), concomitant immunosuppressor treatment (IS) dose and physicians' opinion. A patient was considered as a responder if there was improvement in at least 2 of these 4 criteria and no aggravation in the 2 others.

Results:

Thirty patients were studied (21 women (70%), mean age 52.5 years), 12 with PM, 6 with DM and 12 with AS. Mean disease duration was 6.1 years. All had received IS agents. Twenty-five patients received two doses of 1 gram of RTX 2 weeks apart and 5 patients received four weekly infusions of 375 mg/m2 of RTX. RTX was given alone to 9 patients and in combination with IS to the others. Twenty eight patients received associated CS (mean daily dose 21.4 mg/day). The mean follow up period was 17.2 months.

Twelve adverse events corresponding to 27.9 adverse events per 100 patient-years were reported: two acute infusion reactions of moderate severity, two episodes of undetermined fever, and eight infectious events (18.6 for 100 patients-year) in 7 patients of which seven were mild to moderate, and only one serious (pyelonephritis). Most of these infectious events occurred in the initial 6 months (87.5%).

Efficacy was observed in 21 patients (70%): 8 PM (66.7%), 5 DM (83.3%), 8 AS (66.7%). The mean daily corticosteroid dose (CS) decreased from 21.2 +/- 19.5 to 9.9 +/- 8.5 mg/day. Daily CS dose decreased in 20 patients, increased in 3, and remained unchanged in 7 patients. In patients with elevated CPK level (n=24), it decreased in 19 patients, increased in 5 patients and the mean CPK level decreased from 20,7 ± 29,9 to 11 ± 24,6 times the normal range. Physician opinion on RTX efficacy was favourable for 20 patients and unfavourable for 10. Three patients were considered to be in complete remission with normal CPK level, discontinuation of corticosteroids and in 2 of them discontinuation of IS therapies. Efficacy was not significantly different between patients with or without inflammatory myopathy antibodies [14/17 (82.3%)][7/13(53.8%)] (p = 0.12)]. Mean duration of efficacy in responders was 15.5 months. Ten patients received a second course of RTX; efficacy was observed in 8 with a mean duration of 7.4 months, 1 patient was not evaluated and 1 did not respond.

Conclusions:

Rituximab seems to be an effective and well-tolerated treatment in patients with idiopathic inflammatory myopathies.

To cite this abstract, please use the following information:
Couderc, Marion, Gottenberg, Jacques E., Mariette, Xavier, Hachulla, Eric, Sibilia, Jean, Fain, Olivier, et al; Efficacy and Tolerance of Rituximab in Refractory Idiopathic Inflammatory Myopathy. Data of the AIR Registry. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :917
DOI: 10.1002/art.28685

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