Summary

An investigational selective inhibitor of Janus kinase 1 (JAK1) was found to improve clinical endpoints with a favorable safety profile in a Phase 2a dose-ranging study of patients with rheumatoid arthritis (RA). This article discusses the results of a 4-week double-blind, placebo-controlled study of GLPG0634, an orally-available, selective inhibitor of JAK1, in patients with active RA [Vanhoutte FP et al. EULAR 2013 (poster 0229)].