RT Journal Article SR Electronic T1 Use of Magnetic Resonance Imaging to Support Dose Selection in a Phase II Trial of Baricitinib Combined with Conventional Synthetic Disease-modifying Antirheumatic Drugs in Rheumatoid Arthritis JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.171469 DO 10.3899/jrheum.171469 A1 Charles Peterfy A1 Julie DiCarlo A1 Paul Emery A1 Mark C. Genovese A1 Edward C. Keystone A1 Peter C. Taylor A1 Doug E. Schlichting A1 Scott D. Beattie A1 Monica Luchi A1 William Macias YR 2019 UL http://www.jrheum.org/content/early/2019/01/15/jrheum.171469.abstract AB Objective Magnetic resonance imaging (MRI) was used in a Phase IIb study (NCT01185353) of baricitinib in patients with RA to support dose selection for the Phase III program. Methods 301 patients with active RA on stable methotrexate were randomized 2:1:1:1:1 to placebo or once-daily baricitinib (1-, 2-, 4-, or 8-mg) for up to 24 weeks. 154 patients with definitive radiographic erosion had MRI of the hand/wrist at baseline and weeks 12 and 24. Two expert radiologists, blinded to treatment and visit order, scored images for synovitis, osteitis, bone erosion, and cartilage loss. Combined inflammation (osteitis + 3x synovitis score) and total joint damage (erosion + 2.5x cartilage loss score) scores were calculated. Treatment groups were compared using analysis of covariance adjusting for baseline scores. Results Mean changes from baseline to week 12 for synovitis were -0.10, -1.50, and -1.60 for patients treated with placebo, baricitinib 4-mg, and baricitinib 8-mg, respectively (P=0.003 vs placebo for baricitinib 4- and 8-mg); mean changes for osteitis were 0.00, -3.20, and -2.10 (P=0.001 vs placebo for baricitinib 4-mg and P=0.037 for 8-mg) and mean changes for bone erosion were 0.90, 0.10, and 0.40 (P=0.089 for 4-mg and P=0.275 for 8 mg), respectively in these treatment groups. Conclusion Using MRI findings in this subgroup of patients suggest suppression of synovitis, osteitis, and combined inflammation by baricitinib 4- and 8-mg, which corroborate previously demonstrated clinical efficacy of baricitinib and increase confidence that baricitinib 4-mg could positively effect reduction of the radiographic progression in Phase III studies.