A Ph II/III seamless, multi-center, randomized, double-blind, placebo-controlled study of the reduction in signs and symptoms and inhibition of structural damage during treatment with tocilizumab versus placebo in patients with ankylosing spondylitis who

To assess the: efficacy of treatment with TCZ 4 mg/kg and 8 mg/kg versus placebo in AS patients who are na�ve to treatment with TNF antagonist therapy with regard to the proportion of patients who achieve an ASAS20 response at week 12 (confirmation at week 24) and the safety of TCZ 4 mg/kg and 8 mg/kg versus placebo with regard to AEs and laboratory assessments