Discontinuation of methotrexate in rheumatoid arthritis patients achieving clinical remission by treatment with upadacitinib plus methotrexate (DOPPLER study): A study protocol for an interventional, multicenter, open-label and single-arm clinical trial with clinical, ultrasound and biomarker assessments.

The study results are expected to show the clinical benefit of the discontinuation of MTX after achieving clinical remission by treatment with upadacitinib plus MTX combination therapy. The strength of this study is the prospective evaluation of therapeutic efficacy using clinical disease activity indices and standardized MSUS, which can accurately and objectively evaluate disease activity at the joint level among patients drawn from multiple centers. Furthermore, parameters to predict clinical remission after administration of upadacitinib plus MTX combination therapy and nonclinical relapse after discontinuation of MTX will be screened by integrated multilateral assessments (i.e., clinical disease activity indices, MSUS findings, and serum biomarkers).