Efficacy of abatacept in systemic lupus erythematosus: a retrospective analysis of 11 patients with refractory disease

Objective The objective of this study was to assess the safety and efficacy of abatacept in patients with SLE refractory to conventional treatment in routine clinical practice. Methods This retrospective study included 11 SLE patients treated with abatacept for an active and refractory disease. The primary endpoint was the change in SLE Disease Activity Index (SLEDAI) score at six months. Response was defined as a decrease of SLEDAI 4 in a patient continuing abatacept. Results Indications of abatacept treatment were articular (n=8), renal (n=1) and cutaneous (n=1) involvement and autoimmune thrombocytopenia (n=1). Abatacept was discontinued before six months in two patients, because of adverse event (n=1) and/or lupus flare (n=2). The median SLEDAI decreased from 6 (2-20) to 4 (0-20) (p=0.031). Decrease of SLEDAI 4 was observed in 6/11 patients (55%) and response to treatment according to the physician's judgement in 8/11 (73%) patients. Improvement of articular involvement was observed in 7/8 (87.5%) patients. Four adverse events were observed in three patients, but no severe infection occurred. Conclusion This study suggests some efficacy of abatacept in patients with refractory disease in routine clinical practice, particularly in the case of articular manifestations, with an acceptable safety profile. These data support conducting new controlled trials of abatacept in SLE patients.