Background Therapeutic guidelines draw heavily on evidence from randomized controlled trials undertaken in well-characterized, 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 [1–2].

Objectives To assess subcutaneous (SC) abatacept (ABA) efficacy and safety in a real-life setting.

Methods This was a retrospective and single center study in which 94 patients (1987 ACR) were assessed from April 2014 to January 2016. The patients were stratified according to their treatment background: (n=39) biologic-naïve, (n=22) switched from IV to SC ABA administration (125mg-wk), and (n=33) 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 6 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.

Results Baseline characteristics of patients were as follows: female gender 86%, mean age 55.2±12.3 years, median disease duration 12.5 (IQR 14) years, Rheumatoid Factor positive 94%, Anti-Cyclic Citrullinated Peptide Antibodies 84%, mean DAS28-CRP 5.4±0.72, and mean RAPID3 15.6±5.0. SC ABA monotherapy, concomitant use of methotrexate (MTX), and leflunomide were reported in 10%, 48%, and 27%, respectively. Demographics and disease characteristics were similar in all groups, except for baseline DAS28-CRP (p<0.0001), and RAPID3 (p<0.0001) in switch group. After 6 months of administration, the DAS28-CRP score change was statistically significant irrespective of group. The scores changed from 5.4±0.9 to 3.8±1.3 (p<0.0001, biologic-naïve group), from 3.1±1.2 to 2.7±1.2 (p=0.002, switch IV-SC group), and from 4.6±1.9 to 3.2±1.4 (p=0.0305, TNF-IR group). The RAPID3 scores changed from 18.1±5.4 to 12.1±6.3 (p<0.0001, biologic-naïve group), from 10.4±6.6 to 9.2±7.0 (p=0.0114, switch IV-SC group), and from 16.1±5.7 to 11.8±7.1 (p=0.284, TNF-IR group). No patients relapsed or needed to return to the IV administration. Infections, headache, and constitutional symptoms, occurred in 48%, 37% and 32% of patients, respectively. Serious infections were reported only in 2% of patients (i.e., herpes zoster). Local injection-site reactions occurred in 13% of patients. Most of AEs reported were reversible and mild. There were no treatment discontinuations. No deaths and malignancies were reported.

Conclusions Our results disclose an improvement in RA disease activity and physical function, during 6 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 demonstrated a good safety profile, consistent with previously published data.

1. Reggia R, et al. J Rheumatol 2015;42(2):193–5.

2. Nüβlein H, et al. Arthritis Rheum 2012;64(Suppl10):S199.

Disclosure of Interest None declared