Study to Demonstrate the Efficacy, Safety and Tolerability of an Intravenous Regimen of Secukinumab Compared to Placebo in Subjects With Active axSpA

Inclusion Criteria: Subjects eligible for inclusion in this study must meet all of the following criteria: 1. Subject must be able to understand and communicate with the investigator, comply with the requirements of the study. and must give written, signed and dated informed consent before any study assessment is performed 2. Male and non-pregnant, non-lactating female patients ≥ 18 years of age 3. Diagnosis of axSpA according to ASAS criteria 1. Inflammatory back pain for at least 6 months 2. Onset before 45 years of age 4. For subjects with AS: Diagnosis of AS with prior documented radiologic evidence (x-ray or radiologist's report) fulfilling the Modified New York criteria for AS 5. For subjects with nr-axSpA: X-ray of SIJ negative (centrally read) for AS by Modified NY criteria AND 1. Sacroiliitis on MRI (centrally read) with ≥ 1 SpA feature OR HLA-B-27 positive with ≥2 SpA features AND 2. Objective signs of inflammation at screening, evident by either MRI with SIJ inflammation (centrally read) AND / OR hsCRP \> ULN (as defined by the central lab) 6. Active axial SpA assessed by BASDAI ≥4 cm (0-10 cm) at Baseline 7. Spinal pain as measured by BASDAI question #2 ≥ 4 cm (0-10 cm) at Baseline 8. Total back pain as measured by VAS ≥ 40 mm (0-100 mm) at Baseline 9. Subjects should have had inadequate response or failure to respond to at least 2 NSAIDs at an approved dose for a minimum of 4 weeks in total and a minimum of 2 weeks for each NSAID prior to randomization, or less than 4 weeks if therapy had to be withdrawn due to intolerance, toxicity or contraindications 10. Subjects who are regularly taking NSAIDs (including COX-1 or COX-2 inhibitors) as part of their AS or nr-axSpA therapy are required to be on a stable dose for at least 2 weeks before randomization 11. Subjects who are intolerant or have been inadequate responders to a TNF inhibitor (not more than one) will be allowed to enter into the study (not more than 20% per group). They must have experienced an inadequate response to previous or current treatment at an approved dose for at least 3 months prior to randomization, or have been intolerant to at least one administration of an anti-TNF agent. These subjects will undergo an appropriate wash-out period prior to randomization, if required 1. 4 weeks for Enbrel® (etanercept) - with a terminal half-life of 102 ± 30 hours 2. 8 weeks for Remicade® (infliximab) - with a terminal half-life of 8.0-9.5 days 3. 10 weeks for Humira® (adalimumab) - with a terminal half-life of 10-20 days (average 2 weeks) 4. 10 weeks for Simponi® (golimumab) - with a terminal half-life of 11-14 days 5. 10 weeks for Cimzia® (certolizumab) - with a terminal half-life of 14 days 12. Subjects taking methotrexate (MTX) (≤ 25 mg/week ) or sulfasalazine (≤ 3 g/day) are allowed to continue their medication and must have taken it for at least 3 months and have to be on a stable dose for at least 4 weeks prior to randomization. Subjects on MTX must be on folic acid supplementation before randomization 13. Subjects who are on a conventional DMARD other than MTX or sulfasalazine must discontinue the DMARD 4 weeks prior to randomization, except for leflunomide, which must be be discontinued 8 weeks prior to randomization, unless a cholestyramine washout has been performed 14. Subjects taking systemic corticosteroids must be on a stable dose of ≤10 mg/day prednisone or equivalent for at least 2 weeks before randomization Exclusion Criteria: Subjects meeting any of the following criteria are not eligible for inclusion in this study 1. Subjects with total ankylosis of the spine 2. Chest x-ray or MRI with evidence of ongoing infectious or malignant process obtained within 3 months of screening and evaluated by a qualified physician 3. Subjects taking moderate and high potency opioid analgesics (e.g. methadone, hydromorphone, morphine) 4. Presence of significant medical problems which at investigator's discretion, will prevent the subject from participating in the study, including but not limited to the following: Subjects with severely reduced kidney function (estimated glomerular filtration rate (eGFR) \<29 ml/min/1.73m2), history of renal trauma, glomerulonephritis, or patients with one kidney only, or a serum creatinine level exceeding 1.5 mg/dl (132.6 μmol/L) 5. Any therapy by intra-articular injections (e.g. corticosteroid) within 4 weeks before Randomization 6. Underlying conditions (including, but not limited to metabolic, hematologic, renal, hepatic, pulmonary, neurologic, endocrine, cardiac, infectious or gastrointestinal) which in the opinion of the investigator significantly immunocompromises the subject and/or places the subject at unacceptable risk for receiving an immunomodulatory therapy 7. Any medical or psychiatric condition which, in the Investigator's opinion, would preclude the participant from adhering to the protocol or completing the study per protocol 8. Active systemic infections during the last two weeks (exception: common cold) prior to randomization or any infection that reoccurs on a regular basis 9. History of ongoing, chronic or recurrent infectious disease or evidence of tuberculosis infection as defined by either a positive purified protein derivative (PPD) skin test (the size of induration will be measured after 48-72 hours, and a positive result is defined as an induration of ≥ 5 mm or according to local practice/guidelines) or a positive QuantiFERON TB-Gold test as indicated in the assessment schedule in Table 8-1. Subjects with a positive test may participate in the study if further work up (according to local practice/guidelines) establishes conclusively that the subject has no evidence of active tuberculosis. If presence of latent tuberculosis is established, then treatment according to local country guidelines must have been initiated 10. Past medical history of infection with HIV or hepatitis B prior to randomization or active infection or on treatment for Hepatitis C at randomization 11. History of lymphoproliferative disease or any known malignancy, or history of malignancy of any organ system treated or untreated within the past 5 years, regardless of whether there is evidence of local recurrence or metastases (except for skin Bowen's disease, or basal cell carcinoma or actinic keratoses that have been treated with no evidence of recurrence in the past 12 weeks; carcinoma in situ of the cervix or non-invasive malignant colon polyps that have been removed) 12. Use or planned use of prohibited concomitant medication (see Section 6.2.2) 13. Inability or unwillingness to undergo repeated venipuncture (e.g., because of poor tolerability or lack of access to veins) 14. Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test 15. History or evidence of ongoing alcohol or drug abuse, within the last six months before randomization 16. Screening total WBC count \<3,000/μl, or platelets \<100,000/μl or neutrophils \<1,500/μl or hemoglobin \<8.5 g/dl (85 g/L) 17. History of clinically significant liver disease or liver injury indicated by abnormal liver function tests, such as SGOT (AST), SGPT (ALT), alkaline phosphatase and serum bilirubin. The investigator should be guided by the following criteria: * Any single parameter may not exceed 2 x the upper limit of normal (ULN). A single parameter elevated up to and including 2 x ULN should be re-checked once more as soon as possible, and in all cases, at least prior to randomization, to rule-out laboratory error. * If the total bilirubin concentration is increased above 2 x ULN, total bilirubin should be differentiated into the direct and indirect reacting bilirubin. In any case, serum bilirubin should not exceed the value of 1.6 mg/dL (27 µmol/L) 18. Significant medical problems or diseases, including but not limited to the following: uncontrolled hypertension (≥160/95 mmHg), congestive heart failure (New York Heart Association status of class III or IV), uncontrolled diabetes, or very poor functional status precluding ability to perform self-care 19. Plans for administration of live vaccines during the study period or within 6 weeks prior to randomization 20. Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using effective methods of contraception during the entire study or longer if required by locally approved prescribing information (e.g., 20 weeks in EU). Effective contraception methods include: * Total abstinence (when this is in line with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception * Female sterilization (have had surgical bilateral oophorectomy with or without hysterectomy) or tubal ligation at least six weeks before taking study treatment. In case of oophorectomy alone, only when the reproductive status of the woman has been confirmed by follow up hormone level assessment * Male sterilization (at least 6 months prior to screening). For female subjects on the study, the vasectomized male partner should be the sole partner for that subject * Barrier methods of contraception: Condom or Occlusive cap (diaphragm or cervical/vault caps). For UK: with spermicidal foam/gel/film/cream/ vaginal suppository * Use of oral, injected or implanted hormonal methods of contraception or other forms of hormonal contraception that have comparable efficacy (failure rate \<1%), for example hormone vaginal ring or transdermal hormone contraception * Placement of an intrauterine device or intrauterine system In case of use of oral contraception women should have been stable on the same pill for a minimum of 3 months before taking study treatment. Women are considered post-menopausal and not of child bearing potential if they have had 12 months of natural (spontaneous) amenorrhea with an appropriate clinical profile (e.g., age appropriate, history of vasomotor symptoms) or have had surgical bilateral oophorectomy (with or without hysterectomy) or tubal ligation at least six weeks prior to randomization. In the case of oophorectomy alone, only when the reproductive status of the woman has been confirmed by follow up hormone level assessment is she considered not of childbearing potential. 21. Active ongoing inflammatory diseases other than axSpA that might confound the evaluation of the benefits of secukinumab therapy, including inflammatory bowel disease or uveitis 22. Current severe progressive or uncontrolled disease which in the judgment of the clinical investigator renders the subject unsuitable for the trial 23. Use of other investigational drugs at the time of enrollment, or within 5 half- lives of enrollment, or within 4 weeks until the expected pharmacodynamic effect has returned to baseline, whichever is longer; or longer if required by local regulations 24. History of hypersensitivity to any of the study drug constituents 25. Previous exposure to secukinumab (AIN457) or any other biologic drug directly targeting IL-17 or the IL-17 receptor 26. Previous treatment with any cell-depleting therapies including but not limited to anti-CD20 or investigational agents (e.g., CAMPATH, anti-CD4, anti-CD5, anti-CD3, anti-CD19)