An Efficacy and Safety Study of Tocilizumab (RoActemra/Actemra) in Participants With Giant Cell Arteritis (GCA)

Inclusion Criteria:

• Diagnosis of GCA classified according to age >/=50 years; history of ESR >/=50 mm/hror history of CRP >/=2.45 mg/dL; and at least one of the following: unequivocalcranial symptoms of GCA or symptoms of polymyalgia rheumatica [PMR]; and at least oneof the following: temporal artery biopsy revealing features of GCA or evidence oflarge-vessel vasculitis by angiography or cross-sectional imaging

• New onset (diagnosis within 6 weeks of baseline) or refractory (diagnosis greater than [>] 6 weeks before baseline and previous treatment with >/= 40 milligrams per dayprednisone [or equivalent] for at least 2 consecutive weeks at any time) GCA

• Active disease (presence of clinical signs and symptoms [cranial or PMR] and ESR >/=30mm/hour or CRP >/=1 mg/dL) within 6 weeks of baseline visit

Exclusion Criteria:

• Major surgery within 8 weeks prior to screening or planned within 12 months afterrandomization

• Transplanted organs (except corneas with transplant performed >3 months prior toscreening)

• Major ischemic event, unrelated to GCA, within 12 weeks of screening

• Prior treatment with any of the following: investigational agent within 12 weeks (or 5half-lives of the investigational drug, whichever is longer) of screening;cell-depleting therapies including investigational agent; intravenous (IV) gammaglobulin or plasmapheresis within 6 months of baseline; alkylating agents or withtotal lymphoid irradiation; tocilizumab; hydroxychloroquine, cyclosporine A,azathioprine, or mycophenolate mofetil within 4 weeks of baseline; etanercept within 2weeks of baseline; infliximab, certolizumab, golimumab, abatacept, or adalimumabwithin 8 weeks of baseline; anakinra within 1 week of baseline; tofacitinib;cyclophosphamide within 6 months of baseline; >100 milligrams of daily IVmethylprednisolone within 6 weeks of baseline

• Participants requiring systemic glucocorticoids for conditions other than GCA, which,in the opinion of the investigator, would interfere with adherence to the fixedglucocorticoid taper regimen and/or to assessment of efficacy in response to the testarticle

• History of severe allergic reactions to monoclonal antibodies or to prednisone

• Evidence of serious uncontrolled concomitant disease (for example, cardiovascular,respiratory, renal, endocrine, psychiatric, corneal ulcers/injuries, orgastrointestinal [GI] disease)

• Current liver disease, as determined by the investigator

• History of diverticulitis, inflammatory bowel disease, or other symptomatic GI tractcondition that might predispose to bowel perforation

• Known active or history of recurrent bacterial, viral fungal, mycobacterial, or otherinfection

• Primary or secondary immunodeficiency

• Evidence of malignancies diagnosed within previous 5 years (except basal and squamouscell carcinoma of the skin or carcinoma in situ of the cervix uteri that have beenexcised and cured)

• Inadequate hematologic, renal or liver function

• Positive for hepatitis B or hepatitis C infection