ACR70-disease activity score remission achievement from switches between all the available biological agents in rheumatoid arthritis: a systematic review of the literature.

INTRODUCTION: The aim of our analysis was to compare the gaining of a major response (disease activity score [DAS] remission or American College of Rheumatology 70% improvement criteria [ACR70]) by switching between all the available biological therapies in rheumatoid arthritis. METHODS: A systematic review was performed including studies, published before December 2008, in which a second biological agent was used and clinical outcomes were evaluated after a first biological failure. RESULTS: Nine articles were included. Switching from etanercept and/or infliximab to adalimumab is effective with an ACR70 response ranging from 5% to 33%. Rituximab may be slightly more effective than switching to a second anti-tumor necrosis factor-alpha (anti-TNFalpha), reaching an ACR70 or DAS remission response in 12% and 9%, respectively. Clinical trials confirmed the efficacy in switching to abatacept (gain of effect 10.2%). Tocilizumab allows DAS28 (DAS using 28 joint counts) remission in 30.1% but ACR70 only in 12.4% of patients refractory to anti-TNFalpha. CONCLUSIONS: The efficacy of a second biological agent, irrespective of the mode of action, in reaching an ACR70 or DAS remission after a first biologic is observed from 5% to 15% and from 9% to 15.4%, respectively (except in two studies).