SAT0138 Analysis of Treatment Retention Rate of Biologics Therapy in Patients with Rheumatoid Arthritis – A Single Center Cohort Study

BackgroundBiologics (Bio) therapy has become a standard therapy in the treatment of rheumatoid arthritis (RA) and long-term outcomes can be evaluated recently. Although one of the desirable treatment strategy is to stop Bio therapy after reaching targets to treat such as remission or low disease activity (Bio-free), other desirable treatment strategy is to continue Bio therapy and to sustain targets to treat. Several studies showed it difficult to continue Bio-free for a long time, so it is a practical strategy to continue Bio therapy in clinical setting.ObjectivesThis observational cohort study investigated the treatment retention rate of Bio therapy and the predictors of its continuation in patients with RA.Methods254 RA patients who initiated any of biologic agents (infliximab, etanercept, adalimumab, tocilizumab, abatacept, golimumab) as first Bio in our institute from 2003 to 2013 were included in this study. Switching from one Bio agent to another was defined as continuation of Bio therapy in this study. Patients' characteristics and treatment retention rate were investigated. The outcomes at last observation in both the Bio-continued and the Bio-stopped were compared with each other. Bio-free due to remission and stopping Bio therapy related to pregnancy were assigned to the Bio-continued. The predictors for continuation of the Bio therapy were also investigated.ResultsBaseline characteristics was as follows. % female was 82.7%. Mean age was 57.8 years old. Mean RA duration was 11.3 years. % methotrexate (MTX) concomitant was 81.5% and mean used dose was 8.5mg/weeks (MTX dose was restricted up to 8mg/weeks until 2011 in Japan and 16mg/w after 2011). % prednisolone (PSL) concomitant was 56.3%. % Bio monotherapy was 13.6%. Mean baseline DAS28-CRP and SDAI was 4.74 and 25.8, respectively. % high disease activity measured using DAS28 and SDAI at baseline was 41.7% and 46.3%, respectively. Baseline disease activity were getting lower year by year. Treatment continuation rates using Kaplan-Meier method were 88.4% at 1 year, 82.1% at 3 years, 74.4% at 5 years and 70.4% at 7 years. Reasons for stopping Bio therapy were infection at first, hope of patients or absent to hospital at second and worsened comorbidities at third. Lower disease activity and more remission rates were observed in the Bio- continued compared with the Bio-stopped. Predictors of continuation of Bio therapy were shorter RA duration, fewer concomitant prednisolone, more concomitant MTX, l