351. EFFECTS OF BASELINE PREDNISONE DOSE ON REMISSION AND DISEASE FLARE IN PATIENTS WITH GIANT CELL ARTERITIS TREATED WITH TOCILIZUMAB IN A PHASE 3 RANDOMIZED CONTROLLED TRIAL. (29th March 2019) - Stone, John; Tuckwell, Katie; Dimonaco, Sophie; Klearman, Micki; Aringer, Martin; Blockmans, Daniel; Brouwer, Elisabeth; Cid, Maria; Dasgupta, Bhaskar; Rech, Juergen; Salvarani, Carlo; Schulze-Koops, Hendrik; et al.