A Randomized, Double-blind, Parallel Group Placebo-controlled Study of the Safety and Reduction of Signs and Symptoms During Treatment With Tocilizumab (TCZ) Versus Placebo in Patients With Ankylosing Spondylitis Who Have Had an Inadequate Response to Previous TNF Antagonist Therapy

Inclusion Criteria:

- Adult patients ≥ 18 years of age.

- Ankylosing spondylitis as defined by the modified New York criteria for ≥ 3 months
prior to baseline.

- Active disease at screening and baseline (Bath Ankylosing Spondylitis Disease
Activity Index [BASDAI] ≥ 4.0, spinal pain visual analog scale [VAS] ≥ 40).

- Inadequate response or intolerant to 1 or more previous non-steroidal
anti-inflammatory drugs (NSAIDs).

- Inadequate response to treatment with etanercept, infliximab, adalimumab, or
golimumab because of inadequate efficacy.

- Tumor necrosis factor (TNF) antagonist therapy must have been discontinued at least 8
weeks prior to baseline (etanercept 4 weeks).

- Traditional disease-modifying anti-rheumatic drugs (DMARDs) must be withdrawn for at
least 4 weeks prior to baseline (methotrexate, sulfasalazine, and hydroxychloroquine
or chloroquine may be allowed if at stable dose for at least 4 weeks prior to
baseline).

- Oral corticosteroids (≥ 10 mg/day prednisone or equivalent) and
NSAIDs/cyclooxygenase-2 [COX-2] inhibitors must be at stable dose for at least 4
weeks prior to baseline.

Exclusion Criteria:

- Major surgery (including joint surgery) within 8 weeks prior to screening or planned
major surgery within 6 months after randomization.

- Total ankylosis of spine (as determined by investigator).

- Inflammatory rheumatic disease other than ankylosing spondylitis.

- Active, acute uveitis at baseline.

- Previous treatment with tocilizumab.

- Intra-articular or tendon injections or parenteral corticosteroids within 4 weeks
prior to screening.

- History of severe allergic or anaphylactic reactions to humanized or murine
monoclonal antibodies.

- Active current or history of recurrent bacterial, viral, fungal, mycobacterial, or
other infection.

- History of or currently active primary or secondary immunodeficiency.

- Body weight > 150 kg.