Objective: To assess the safety, tolerability and efficacy of abatacept in patients with rheumatoid arthritis (RA) who had failed anti-tumour necrosis factor (TNF) therapy and were switched to abatacept directly or after completing washout.
Methods: In this international, 6-month, open-label trial, patients had active RA, an inadequate response to anti-TNF therapy for ≥3 months and a DAS28 (CRP) of ≥5.1. 'Washout' patients discontinued anti-TNF therapy ≥2 months pre-screening; 'direct-switch' patients began abatacept (~10 mg/kg) at their next scheduled anti-TNF therapy dose.
Results: In total, 1046 patients were treated (449 washout, 597 direct-switch; baseline characteristics were similar between groups). At 6 months, adverse events ([AEs] 78.0 vs 79.2%), serious AEs (SAEs; 11.1 vs 9.9%) and discontinuations due to AEs (3.8 vs 4.0%) and SAEs (2.0 vs 1.3%) were comparable in washout versus direct-switch patients. There were no opportunistic infections. At 6 months, in washout versus direct-switch patients, similar clinically meaningful improvements were seen in DAS28 (CRP) (≥1.2 unit improvement, 59.5 vs 53.6%, respectively; LDAS, 22.5 vs 22.3%; DAS28-defined remission,12.0 vs 13.7%), physical function (HAQ-DI ≥0.22 improvement; 46.3 vs 47.1%) and health-related QoL (mean change in SF-36 scores; PCS, 5.5 vs 6.1; MCS, 4.8 vs 5.4).
Conclusion: Abatacept demonstrated acceptable safety and tolerability, and clinically meaningful efficacy over 6 months in patients with an inadequate response to anti-TNF therapy. Results were comparable regardless of whether there was a washout or not, supporting direct-switching from anti-TNF therapy to abatacept as an option in clinical practice.