Better Retention of Abatacept Is Associated with High Rheumatoid Factor: A Five-Year Follow-Up Study of Patients with Rheumatoid Arthritis.

Recently, biological disease-modifying antirheumatic drugs (bDMARDs) have revolutionized the treatment of rheumatoid arthritis (RA) and provided patients with a higher chance of achieving clinical remission. Among them, abatacept (ABT), which selectively inhibits T cell activation through blocking costimulation signal, has been reported efficacious in controlling disease activity. Previous studies have shown that ABT has a high retention rate of up to three years with tolerable adverse events; however, it remains unclear whether this is maintained in the longer term. Here we conducted a retrospective five-year follow-up study to explore prognostic factors concerning better retention. In total, 98 patients who were treated with ABT from May 2011 to July 2019 in Osaki Citizen Hospital were enrolled, including 73 female patients (74.5%). The Kaplan-Meier method was used to estimate the retention rate of ABT. The mean age of ABT initiation was 72.1 years. Concomitant methotrexate was prescribed for 39 patients, and ABT was used as the first-line bDMARD for 65 patients. Rheumatoid factor (RF) was positive in 79 patients. One-, three-, and five-year retention rates of ABT were 83.3%, 66.2%, and 62.7%, respectively. Approximately two-thirds of discontinuation resulted from an inadequate response. Multivariate logistic regression analysis revealed that positive RF was associated with better drug retention. Receiver operating characteristics analysis showed that patients with high RF (≥ 45 IU/mL) had better retention rate of ABT. In conclusion, ABT shows high retention rate among patients with positive RF. The present study may provide better insights when selecting bDMARDs.