The purpose of this trial is to demonstrate the clinical efficacy at week 16; and to demonstrate safety and tolerability of secukinumab compared to placebo in patients with ankylosing spondylitis at week 16 and long term safety up to Week 52.

This multicenter study used a randomized, double-blind, placebo-controlled, parallel-group design. A screening period running up to 10 weeks before randomization was used to assess eligibility, followed by 52 weeks of treatment.

At baseline, subjects were randomized to one of the two treatment groups:

• Group 1: 300 subjects, secukinumab 150 mg (1 mL, 150 mg/mL) s.c. pre-filled syringes (PFS) at BSL, Weeks 1, 2, and 3, followed by administration every four weeks starting at Week 4
• Group 2: 150 subjects, placebo (1 mL) s.c. PFS at BSL, Weeks 1, 2, 3, 4, 8, and 12, followed by secukinumab 150 mg (1 mL, 150 mg/mL) administration every four weeks starting at Week 16

The subjects were stratified at randomization according to the region (China and non-China). Approximately 70% of randomized subjects were from China (327 Chinese subjects) in order to evaluate the efficacy and safety in this subject population. No more than 30% TNFα inhibitor inadequate responders (TNF-IR) subjects were to be enrolled in the study.

Starting at Week 16, all subjects switched to open-label secukinumab 150 mg, including all placebo subjects; however, all subjects and investigators/site staff remained blinded to the original randomized treatment group assignment (150 mg vs placebo). Study treatment continued up to Week 48.

An end of treatment visit was done 4 weeks after last study treatment administration and a post treatment follow-up visit was done 12 weeks after last study treatment administration for all subjects (regardless of whether they completed the entire study as planned or discontinued prematurely).

Subjects were instructed in detail how to self-administer the s.c. injection using PFS. Each injection was administered into an appropriate injection site of the body (thighs, arms, or abdomen). All injections were performed at the study site. Site personnel administered the injections to subjects who were not able to, or felt insecure to self-administer. Rescue medication was not allowed until Week 20. However, subjects who were 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 were free to discontinue participation in the study at any time.

Inclusion Criteria:

Male or non-pregnant, non-lactating female patients at least 18 years of age

Diagnosis of moderate to severe AS with prior documented radiologic evidence (x-ray or radiologist's report) fulfilling the Modified New York criteria for AS:

• Active AS assessed by BASDAI ≥4 (0-10) at Baseline
• Spinal pain as measured by BASDAI question #2 ≥ 4 cm (0-10 cm) at Baseline
• Total back pain as measured by VAS ≥ 40 mm (0-100 mm) at Baseline Patients 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 Patients who are regularly taking NSAIDs (including COX-1 or COX-2 inhibitors) as part of their AS therapy are required to be on a stable dose for at least 2 weeks before randomisation Patients who have been on a TNFα inhibitor (not more than one) must have experienced an inadequate response to previous or current treatment given at an approved dose for at least 3 months prior to randomization or have been intolerant to at least one administration of an anti-TNFα agent

Exclusion Criteria:

• Chest X-ray or MRI with evidence of ongoing infectious or malignant process

  • Patients taking high potency opioid analgesics
  • Previous exposure to secukinumab or any other biologic drug directly targeting IL-17 or IL-17 receptor
  • Pregnant or nursing (lactating) women

Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect 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