Remission induction by Raising the dose of Remicade in RA (RRRR) study: Rationale and study protocol for a randomized controlled trial comparing for sustained clinical remission after discontinuation of infliximab in patients with rheumatoid arthritis.

Infliximab, an inhibitor of TNF-α, is one of the most widely used biological disease-modifying antirheumatic drugs. Recent studies indicated that baseline serum TNF-α could be considered as a key indicator for optimal dosing of infliximab for RA treatment to achieve the clinical response and its sustained remission. The Remission induction by Raising the dose of Remicade in RA (RRRR) study is an open-label, parallel group, multicenter randomized controlled trial to compare the proportions of clinical remission based on the simplified disease activity index (SDAI) after 1 year of treatment and its sustained remission rate after another 1 year between the investigational treatment strategy (for which the dose of infliximab was chosen based on the baseline serum TNF) and the standard strategy of 3 mg/kg per 8 weeks of infliximab administration in infliximab-naïve patients with RA showing an inadequate response to MTX. The primary endpoint is the proportion of patients who kept discontinuation of infliximab 1 year after discontinued infliximab at the time of 54 weeks after the first administration of infliximab. The secondary endpoints are the proportion of clinical remission based on SDAI and changes in SDAI from baseline at each time point, other clinical parameters, quality of life measures and adverse events. Target sample size of randomized patients is 400 patients in total. The main results of the RRRR study are expected to be published at the end of 2017.