Characteristics of patients with difficult-to-treat rheumatoid arthritis in clinical practice

The aim of this study was to investigate the clinical characteristics of patients with difficult-to-treat RA (D2T RA) and the usefulness of switching to drugs with different modes of action in real-world. Methods. We reviewed all consecutive patients with RA treated at Keio University Hospital between 2016 and 2017 with a definition of D2T RA. We analysed clinical characteristics and evaluated the usefulness of changing drugs according to mode of action. Results. Among 1709 patients with RA, 173 (10.1%) were D2T RA. The reason for the D2T RA was multi-drug resistance in 59 patients (34.1%), comorbidity in 17 (9.8%), and socio-economic reasons in 97 (56.1%). The multidrug- resistance group had significantly higher tender joint count and evaluator global assessment than the other groups, despite receiving the most intensive treatment. The comorbidity group showed a significantly older age and higher rheumatic disease comorbidity index. Although changing the drug to another with a different mode of action was useful, the proportion of patients who achieved remission or low disease activity decreased as the number of switches increased. Conclusion. Of the patients with RA, 10.1% were still difficult to treat in clinical practice, despite intensive treatment. Their characteristics were distinct by the reasons of D2T RA, which suggests the need for a personalized approach to D2T RA.