Inclusion Criteria:  Signed informed consent must be obtained prior to participation in the study. Patient must be able to understand and communicate with the investigator and comply with the requirements of the study. Male or non-pregnant, non-lactating female patients at least 50 years of age.  Diagnosis of GCA based on meeting all of the following criteria:  Age at onset of disease ≥ 50 years. Unequivocal cranial symptoms of GCA (new-onset localized headache, scalp or temporal artery tenderness, ischemia-related vision loss, or otherwise unexplained mouth or jaw pain upon mastication), and/or symptoms of polymyalgia rheumatica (PMR) (defined as shoulder and/or hip girdle pain associated with inflammatory morning stiffness) and/or symptoms of limb ischemia (claudication). Temporal artery biopsy (TAB) revealing features of GCA and/or cross-sectional imaging study such as ultrasound (e.g. cranial or axillary), MRA, CTA, or PET-CT with evidence of vasculitis.  Active disease as defined by meeting both of the following within 6 weeks of Baseline:  Presence of signs or symptoms of GCA Elevated erythrocyte sedimentation rate (ESR) ≥ 30 mm/hr or C-reactive protein (CRP) ≥ 10 mg/L attributed to active GCA or active GCA on TAB or imaging study  Patients to meet definition of new-onset GCA or relapsing GCA:  Definition of new-onset GCA: diagnosis of GCA within 6 weeks of Baseline visit Definition relapsing GCA: diagnosis of GCA > 6 weeks before Baseline visit and patient has experienced recurrence of active disease following the institution of a treatment. Patients must be eligible to receive prednisone (or equivalent) 20 mg-60 mg daily at Baseline. Patients taking MTX (≤ 25 mg/week) are allowed to continue their medication provided they have taken it for at least 3 months, are on a stable dose for at least 4 weeks prior to randomization, and if they are on stable folic acid treatment before randomization  Exclusion Criteria:  Previous exposure to secukinumab or other biologic drug directly targeting IL-17 or IL-17 receptor. Patients treated with any cell-depleting therapies. Previous participation in clinical trial for GCA. Patients who have been treated with inhibitors directly targeting IL-1, or IL-1 receptor, IL-12 and IL-23, or abatacept within 4 weeks or within 5 half-lives of the drug (whichever is longer) prior to Baseline. Treatment with tocilizumab, other IL-6/IL6-R inhibitor or JAK inhibitor within 12 weeks or within 5 half-lives of the drug (whichever is longer) prior to Baseline, or if patient did not respond to or experienced a relapse during treatment any time before Baseline. Any treatment received for GCA other than GCs and patient did not respond to treatment or experienced a relapse during treatment any time before Baseline. Patients treated with i.v. immunoglobulins or plasmapheresis within 8 weeks prior to Baseline. Patients treated with cyclophosphamide, tacrolimus, everolimus, hydroxychloroquine, cyclosporine A, azathioprine, sulfasalazine, mycophenolate mofetil within 6 months prior to Baseline. Patients treated with leflunomide within 8 weeks of Baseline unless a cholestyramine washout has been performed in which case the patient must be treated within 4 weeks of Baseline. Patients treated with an alkylating agent within 5 years prior to Baseline, unless specified in other exclusion criteria. Patients requiring systemic chronic glucocorticoid therapy for any other reason than GCA. Receipt of > 100 mg daily intravenous methylprednisolone pulse therapy within 6 weeks prior to Baseline. Patients requiring chronic (i.e., not occasional "prn") high potency opioid analgesics for pain management. Patients treated with any investigational agent within 4 weeks or within 5 half-lives of the drug (whichever is longer) prior to Baseline. Contraindication or hypersensitivity to secukinumab. Active ongoing inflammatory diseases other than GCA that might confound the evaluation of the benefit of secukinumab therapy, including inflammatory bowel disease or uveitis. Major ischemic event (e.g. myocardial infarction, stroke, etc.) or transient ischemic attack (TIA) (except ischemia-related vision loss), related or unrelated to GCA, within 12 weeks of screening. Confirmed diagnosis of any primary form of systemic vasculitis, other than GCA. Any other biologics within 4 weeks or within 5 half-lives of the drug (whichever is longer) prior to Baseline. Active ongoing diseases which in the opinion of the investigator immunocompromises the patient and/or places the patient at unacceptable risk for treatment with immunomodulatory therapy. Active systemic infections during the last 2 weeks (exception: common cold) prior to randomization. History of ongoing, chronic or recurrent infectious disease or evidence of tuberculosis infection as defined by a positive QuantiFERON TB- Gold Plus test. Patients with a positive test may participate in the study if further work up (according to local practice/guidelines) establishes conclusively that the patient has no evidence of active tuberculosis. If presence of latent tuberculosis is established then treatment according to local country guidelines must be initiated prior to randomization. Live vaccinations within 6 weeks prior to Baseline or planned vaccination during study participation until 12 weeks after last study treatment administration.