<h3>Background</h3> Therapeutic guidelines draw heavily on evidence from randomised controlled trials undertaken in well-characterised, highly-selective populations and managed in tightly-controlled settings. As such, the extent to which therapeutic efficacy in real-life populations and routine care settings is often unclear. <h3>Objectives</h3> To assess subcutaneous (SC) abatacept (ABA) efficacy and safety in a real-life setting. <h3>Methods</h3> This was a retrospective and single center study in which 70 patients (1987 ACR) were assessed from April 2014 to December 2014. The patients were stratified according to their treatment background: biologic-naïve, switched from IV to SC ABA administration (125mg-wk), and inadequate response to TNF inhibitor (TNF-IR). The primary and secondary endpoints were change in DAS28-CRP, and Routine Assessment of Patient Index Data (RAPID3) from baseline to 9 months, respectively. A linear mixed effects model was made to account for correlation among repeated measures. Adverse events (AEs) were assessed and recorded at each visit to the rheumatology center. <h3>Results</h3> Baseline characteristics of patients were as follows: female gender 84.3%, mean age 54.9±10.6 years, median disease duration 12.5 (IQR 14) years, Rheumatoid Factor or Anti-Cyclic Citrullinated Peptide Antibodies seropositivity 93.8%, erosive disease 32.9%, SC ABA monotherapy 48.5%, concomitant use of methotrexate (MTX) 38.5%, mean DAS28-CRP 4.61±1.59, and mean RAPID3 15.2±7.1. Demographics and disease characteristics were similar in the three groups (including MTX use), except for baseline DAS28-CRP (p<0.0001), and RAPID3 (p=0,0009) in switch group. After 9 months of administration, the DAS28-CRP scores changed from 5.28±1.09 to 4.01±1.3 (p<0.0001, biologic-naïve group), from 3.21±1.24 to 2.8±0.87 (p<0.0001, switch IV-SC group), and from 4.6±1.83 to 3.43±1.22 (p<0.0001, TNF-IR group). The RAPID3 score change was statistically significant (p<0.0001) irrespective of group (18.5±5.6 to 12.5±6.7, 11.6±7.0 to 9.1±6.7, and 14.9±7.2 to 11.6±6.8, respectively). No patients relapsed and needed to return to the IV administration. Infections, constitutional symptoms and headache occurred in 46.9%, 40% and 38.6% of patients, respectively. Local injection-site reactions occurred in 10% of patients. Most of AEs reported were reversible and mild. There were 3 discontinuations of treatment due to inefficacy, serious AE (herpes zoster), and persistent respiratory symptoms. No deaths and malignancies were reported. <h3>Conclusions</h3> Our results disclose an improvement in RA disease activity and physical function, during 9 months administration of SC ABA. Patients switching from IV to SC formulation of ABA had lower activity and functional impairment at baseline, and efficacy was maintained through follow-up. SC ABA demostrated a good safety profile, consistent with previously published data. <h3>References</h3> Nüßlein H, et al. Arthritis Rheum 2012;64(Suppl10):S199. Pincus T, et al. Rheumatology (Oxford). 2008 Mar;47(3):345-9. Reggia R, et al. J Rheumatol. 2014 Dec 15 [Epub ahead of print]. <h3>Disclosure of Interest</h3> None declared
