Low rates of radiographic progression of structural joint damage over 2 years of baricitinib treatment in patients with rheumatoid arthritis

Background: In ph3 studies, baricitinib (bari) inhibited progression of radiographic joint damage for up to 1 year in patients (pts) with active rheumatoid arthritis (RA) who were DMARD-naïve or who had an inadequate response to conventional synthetic DMARDs (csDMARD-IR). Objectives: To evaluate radiographic progression of structural joint damage in pts with RA over 2 years of treatment. Methods: Upon completion of a bari ph 3 study, pts could enter a long-term extension (LTE) study, in which they continued to receive the same bari dose as in the original ph3 study. At 52 wks, DMARD-naïve pts receiving methotrexate (MTX) or combination therapy (bari 4mg + MTX) were switched to bari 4mg monotherapy; MTX-IR pts receiving adalimumab (ADA) were switched to bari 4mg on background MTX. At 24 wks, csDMARD-IR pts receiving placebo (PBO) were switched to 4mg on background csDMARD. Radiographs at baseline, year 1 and year 2 were scored using the van der Heijde modified total sharp score (mTSS). Data are least squares mean change from baseline using mixed model repeated measures on observed data. Results: Of all pts randomised, 82.5% entered the LTE, and 87.6% of those could be entered in this analysis. At year 2, progression was significantly lower with initial bari (including monotherapy) vs. initial MTX in DMARD-naïve pts. In MTX/csDMARD-IR pts, progression with initial bari was significantly lower than initial PBO, and similar to initial ADA. Conclusions: Treatment with once-daily oral bari resulted in low rates of radiographic progression for up to 2 years. Pts starting with bari showed progression that was significantly less than those starting with PBO or MTX, and comparable to those starting with ADA. The most robust benefit was seen with the 4mg dose.