This multicenter study uses a randomized, double-blind, placebo-controlled, parallel-group design to study the efficacy, safety, and tolerability of treatment with intravenous secukinumab (initial dose of 6 mg/kg followed thereafter with 3 mg/kg administered every four weeks starting at Week 4) in subjects with active axSpA. The study population consists of approximately 400 subjects with active AS and approximately 100 subjects with active nr-axSpA, despite current or previous NSAID, conventional DMARD and / or TNF inhibitor therapy, or intolerance to these therapies. A screening (SCR) period of up to 10 weeks will be used to assess eligibility, followed by randomization to 52 weeks of study treatment.

At baseline, subjects with active AS and nr-axSpA will be randomized to one of the two treatment groups:

• Group 1: approximately 200 AS subjects and approximately 50 nr-axSpA subjects; These subjects will receive secukinumab 6 mg/kg i.v. at randomization (Baseline (BSL) visit), followed by the administration of secukinumab 3 mg/kg i.v. every four weeks starting at Week 4 through Week 48 (exposure through Week 52).
• Group 2: approximately 200 AS subjects and approximately 50 nr-axSpA subjects; These subjects will receive i.v. placebo at randomization (BSL visit), Weeks 4, 8, and 12 , followed by the administration of secukinumab 3 mg/kg i.v. at Week 16 and every four weeks through Week 48 (exposure through Week 52).

This study will consist of 4 periods totaling up to 70 weeks: the screening period (up to 10 weeks), the treatment period 1 (total duration of 16 weeks) and the treatment period 2 (total duration of 36 weeks) followed by the safety follow up period of 8 weeks after the end of treatment visit (i.e., Week 52).

The subjects will be stratified at randomization according to disease condition (i.e., AS or nr-axSpA). No more than 20% TNF Inhibitor Incomplete Responders (TNF-IR) subjects will be enrolled in the study. Starting at Week 16, all subjects will switch to open-label intravenous secukinumab, including all placebo subjects.

No subject will be on placebo treatment after Week 16. Although study treatment is open label secukinumab i.v. starting at Week 16, all subjects and investigators/site staff will remain blinded to original treatment assignment, so as to ensure unbiased efficacy and safety assessments for the remainder of the study. Study treatment will continue up to Week 52. An end of treatment visit (i.e., Week 52) is to be done 4 weeks after last study treatment administration and a post treatment follow-up visit (i.e., Week 60) is to be done 8 weeks after the end of treatment visit for all subjects (regardless of whether they complete the entire study as planned or discontinue prematurely). All i.v. infusions will be performed at the study site and site personnel will administer the infusions to subjects.

Rescue medication is not allowed until Week 16. However, subjects who are deemed by the investigator not to be benefiting from the study treatment based on safety and efficacy assessments or for any reason of their own accord will be free to discontinue participation in the study at any time. The study will have a primary endpoint analysis at Week 16. Therefore, the primary analysis will be performed with Week-16 data once the last subject has completed the Treatment Period 1.

Clinical management of axSpA by pharmacotherapy includes the use of NSAIDs and conventional DMARDs, and if insufficient response, biologic agents (i.e., TNF-inhibitor therapy or anti-IL17 agents).

This study intends to enroll patients with active disease despite current or previous NSAIDs, conventional DMARDs and/or TNF inhibitor therapy or intolerance to these therapies. A background of NSAID therapy and/or concomitant therapy with methotrexate (≤25 mg/week) or sulfasalazine (≤ 3 g/day) will be acceptable, if dose and route of administration have been stable for at least two weeks with NSAIDs and/or four weeks with MTX or sulfasalazine, prior to the randomization visit. Inclusion of patients with active axSpA who are TNF-IR (up to 20% in each group) in the study also makes the background patient population more representative of the real world clinical scenario.

A placebo arm up to the primary endpoint at Week 16 is included in this study. Due to the nature of the disease and the outcome measures used (ASAS criteria), a placebo arm is necessary to reliably evaluate the efficacy and safety of the active drug. The treatment duration of the placebo group is relatively short and the placebo group will be re-assigned to active treatment at Week 16. The regular assessment of disease activity ensures that subjects who are experiencing worsening of disease in any of the treatment groups can exit the study at any time upon their own accord or based on the advice of the investigator.

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)

Novartis is committed to sharing access to patient-level data and supporting clinical documents from eligible studies with qualified external researchers. Requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to protect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com