Ultra-short Glucocorticosteroids and Tocilizumab Therapy in GCA Patients

Inclusion Criteria 1. Patients aged older than 50 years with large vessel giant cell arteritis (LV-GCA) 2. PET/CT showing vascular FDG uptake ≥2 in at least one vascular district 3. ESR \>40 mm/h or CRP \>10 mg/l OR Cranial or systemic symptoms of GCA or symptoms of polymyalgia rheumatica (PMR) 4. Patient's written informed consent. Exclusion Criteria 1. Use of more than 10 mg/day of prednisone (or equivalent) for more than 10 consecutive days in the previous three months 2. Rheumatic diseases (except for CPPD/chondrocalcinosis) other than GCA or polymyalgia rheumatica (i.e., RA, autoimmune connectivitides, other systemic vasculitides, a.o.) 3. Chronic use of systemic CS with inability, in the opinion of the investigator, to withdraw CS treatment at day 4 according to protocol 4. Evidence of significant and/or uncontrolled concomitant disease such as, but not limited to, cardiovascular disease, nervous system, pulmonary, renal, hepatic, endocrine (in particular diabetes mellitus) or gastrointestinal disorders (including previous complicated diverticulitis) which, in the investigator's opinion, would preclude patient participation or impact the benefit-risk ratio 5. History of amaurosis fugax,visual loss or diplopia 6. Any condition or general state of health which, in the Investigator's opinion, would preclude participation in the study 7. Actual or recent myocardial infarction (within the last 3 months before screening visit) 8. Significant cardiac disease (NYHA Class III and IV), known severe chronic obstructive pulmonary disease (COPD) (FEV1 \< 50% predicted or Functional dyspnea \> Grade 3 on the MRC Dyspnea Scale) or other significant pulmonary disease 9. Uncontrolled disease (such as asthma, psoriasis or inflammatory bowel disease) where flares are commonly treated with oral or injectable corticosteroids 10. Known active infection of any kind, or any major episode of infection requiring hospitalization or treatment with i.v. anti-infectives within 4 weeks of baseline or completion of oral anti-infectives within 2 weeks before screening visit 11. History of deep space/tissue infection (e.g. fasciitis, abscess, osteomyelitis) within 52 weeks before screening visit 12. Any surgical procedure, including bone/joint surgery within 8 weeks prior before screening visit or planned within the duration of the study 13. History of serious recurrent or chronic infection (for screening for a chest infection a chest radiograph will be performed at screening if not performed within 12 weeks before screening visit 14. Lack of peripheral venous access 15. Body weight \> 150 kg or BMI \> 35 16. Previous treatment with tocilizumab or any other biological agent within last 6 months before screening visit; Rituximab within 12 months before screening visit 17. Treatment with any investigational agent within 28 days of screening visit or 5 half-lives of the investigational drug (whichever is the longer) 18. History of severe allergic or anaphylactic reaction to any biologic agent or known hypersensitivity to any component of tocilizumab 19. Receipt of any vaccine within 28 days prior to screening visit (a patient's vaccination record and need for immunization prior to receiving tocilizumab/placebo must be carefully investigated) 20. Positive tests for hepatitis B surface antigen (HBsAg) or hepatitis C serology 21. Positive Quantiferon-TB® test for latent Tb without subsequent INH prophylaxis 22. Patients with active Tb which had to be treated for Tb within 2 years before the screening visit 23. Absolute neutrophil count (ANC) \< 2.0 x 103/µL, white blood cells \< 2.5 x 103/µL, platelet count \< 100,000/ µL 24. Hemoglobin \< 8.0 g/dL 25. Concentrations of serum IgG and/or IgM below 5.0 mg/mL and 0.40 mg/mL, respectively 26. Serum creatinine \> 2.0 mg/dL (200 µmol/L) 27. Alanine aminotransferase (ALT) or aspartate amino-transferase (AST) \> 1.5 times the upper limit of normal (ULN) 28. Total bilirubin \> 1.5 times the upper limit of normal (ULN) 29. Triglycerides \> 400 mmol/dL (non-fasted) or \> 250 mmol/dL (fasted) at screening 30. Premenopausal status and nursing (definition of postmenopausal status: Female participants who are surgically sterilised / hysterectomised or post-menopausal for longer than 2 years are not considered as being of child-bearing potential) 31. Technical implants such as cardiac pacemakers (for MR-angiogram) 32. Claustrophobia (for MR-angiogram) 33. Known allergy against the contrast media (Multihance® or Dotarem® as alternative) 34. Evidence of malignant disease or malignancies diagnosed within the previous 5 years (except basal and squamous cell carcinoma of the skin or carcinoma in situ of the cervix uteri that have been excised and cured)