Patients enrolled in this study were conventional DMARD experienced. Prior use of biologic therapy as well as parenteral steroids were not permitted. In my understanding, the target is GM-CSF receptor and does not appear to be tissue specific Patients with active or untreated latent TB were expluced from the study See the link for the original article for more details: http://ard.bmj.com/content/early/2017/02/17/annrheumdis-2016-210624