Tocilizumab Plus a Short Prednisone Taper for GCA

This is a single center, open label study that will assess the efficacy and safety of 52 weeks of tocilizumab (TCZ) in combination with 8-weeks of prednisone in 30 patients with active giant cell arteritis (GCA). Active disease is defined as signs and/or symptoms of GCA plus increased inflammatory markers (e.g., erythrosedimentation rate \[ESR\] and/or C-reactive protein \[CRP\]). The study will enroll subjects with new onset and with relapsing/refractory GCA, and consist of a screening phase (up to 6 weeks), a treatment phase (52 weeks) and a safety follow up phase (4 weeks). The primary endpoint of the study, sustained remission, will be assessed at week 52. The definition of sustained remission contains 3 elements: 1. Absence of clinical signs and symptoms of active GCA along with the normalization of the ESR (\< 40 mm/hour) and CRP (\< 10 mg/L). 2. Completion of the pre-specified prednisone taper protocol 3. Absence of disease flare (relapse) since the induction of remission by week 8. Disease flare is defined as the re-appearance of unequivocal signs or symptoms of active GCA (with or without elevation of ESR and/or CRP) or the elevation of the ESR and/or CRP that is thought to be due to active GCA and that requires escape therapy.