Safety and effectiveness of abatacept in systemic sclerosis: The EUSTAR experience

Objective: To analyze the safety and effectiveness of abatacept (ABA) given in routine care to patients with systemic sclerosis (SSc). Methods: Retrospective multicenter observational study that enrolled patients with SSc treated with ABA. We collected epidemiological data and clinical outcomes. First, we analyzed the frequency of adverse effects. Secondly, we compared the evolution of different organ manifestations during ABA treatment. We collected data from 6 months before start of therapy to the last follow-up the following parameters: modified Rodnan Skin Score (mRSS), joints, lung and gastrointestinal involvement, concomitant medications, and laboratory tests. Results: Data on twenty-seven patients with SSc were collected (93% females; 67% limited SSc). Rheumatoid arthritis was the most frequent concomitant autoimmune disease. ILD was present in 15 patients. Anti-Scl 70 antibodies were present in 13 patients and rheumatoid factor and ACPA antibodies were present in eight and seven patients respectively. The main indication to use abatacept was joint involvement (59%) followed by myositis (26%). A total of 16 adverse effects were reported in 28 months of abatacept treatment including five that required hospitalization. Most of them occurred in the first 3 months after starting abatacept. After 12 months, the number of tender and swollen joints decreased compared to baseline (p<0.03 and p<0.02 respectively). Moreover, a beneficial effect of abatacept on HAQ-DI at 3 and 6 months (p<0.05) and on morning stiffness at 6 and 12 months (p<0.03) was observed. We also observed a decrease in the modified Rodnan skin score (p<0.05). No changes in lung or gastrointestinal involvement were found. Conclusions: ABA demonstrated a good safety profile and seems to have some effectiveness on joint involvement and related disability in SSc patients treated in routine care.