Conditions: Spondylitis, Ankylosing
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 306
Healthy volunteers: no

Brief summary:
This randomized, double-blind, placebo-controlled study will evaluate the safety and efficacy of RoActemra/Actemra (tocilizumab) in patients with ankylosing spondylitis (AS) who have failed treatment with non-steroidal anti-inflammatory drugs and are naïve to tumor necrsos factor (TNF) antagonist therapy. In Part 1 of the study, patients will be randomized to receive either RoActemra/Actemra 8 mg/kg intravenously (IV) or placebo every 4 weeks for 12 weeks. In Part 2, patients will be randomized to receive RoActemra at either 8 mg/kg or 4 mg/kg IV or placebo every 4 weeks for 24 weeks. The double-blind treatment period will be followed by open-label treatment with RoActemra/Actemra 8 mg/kg iv every 4 weeks until Week 208 for all patients. Anticipated time on study treatment is 208 weeks.

Detailed description:
This study was planned as a Phase II/III seamless, multicenter, randomized, double-blind, placebo-controlled study in patients with AS who were naïve to TNF antagonist therapy. The study consisted of 2 parts, each preceded by a screening visit and followed by a common open-label extension phase. Recruitment into Part 2 commenced after completion of enrollment for Part 1.

Part 1 was designed as a Phase II study exploring the efficacy and safety of tocilizumab therapy versus placebo. Part 1 was intended to determine whether Part 2 of the study would continue, based on a Week 12 analysis.

Part 2 was designed to provide pivotal Phase III efficacy and safety data for tocilizumab in patients with AS. Approximately 400 patients were to be enrolled. Once randomization into Part 1 was complete, randomization into Part 2 of the study was to be initiated.

Based on the results of the Week 12 Part 1 analyses of the primary endpoint (ASAS20) and secondary endpoints, and in consideration of all available safety data, a benefit/risk assessment was made and it was decided to halt the study because of lack of overall efficacy. Most patients did not complete the 24-week double-blind treatment period in Part 2.

Arms:
arm 1: Participants received intravenous infusions of placebo once every 4 weeks until Week 12. Following the Week 12 visit, participants who completed Part 1 of the study received open-label 8 mg/kg tocilizumab through Week 208. arm 2: Participants received intravenous infusions of 8 mg/kg tocilizumab once every 4 weeks until Week 12. Following the Week 12 visit, participants who completed Part 1 of the study received open-label 8 mg/kg tocilizumab through Week 208. arm 3: Participants received intravenous infusions of placebo once every 4 weeks until Week 24. Participants who did not attain an ASsessment in Ankylosing Spondylitis-20 (ASAS20) response at Week 16 were, at the investigator's discretion, eligible to receive open-label escape therapy consisting of 8 mg/kg tocilizumab. After Week 24, participants were to receive open-label treatment with 8 mg/kg tocilizumab every 4 weeks until Week 104. At the completion of Week 104, all Part 2 participants were to receive tocilizumab 8 mg/kg in the common open-label extension phase, however the study was terminated prior to any participants reaching this stage. arm 4: Participants received intravenous infusions of 4 mg/kg tocilizumab once every 4 weeks until Week 24. Participants who did not attain an ASAS20 response at Week 16 were, at the investigator's discretion, eligible to receive open-label escape therapy consisting of 8 mg/kg tocilizumab. After Week 24, participants were to receive open-label treatment with 8 mg/kg tocilizumab every 4 weeks until Week 104. At the completion of Week 104, all Part 2 participants were to receive tocilizumab 8 mg/kg in the common open-label extension phase, however the study was terminated prior to any participants reaching this stage. arm 5: Participants received intravenous infusions of 8 mg/kg tocilizumab once every 4 weeks until Week 24. Participants who did not attain an ASAS20 response at Week 16 were, at the investigator's discretion, eligible to receive open-label escape therapy consisting of 8 mg/kg tocilizumab. After Week 24, participants were to receive open-label treatment with 8 mg/kg tocilizumab every 4 weeks until Week 104. At the completion of Week 104, all Part 2 participants were to receive tocilizumab 8 mg/kg in the common open-label extension phase, however the study was terminated prior to any participants reaching this stage.

Interventions: intervention 1: tocilizumab intervention 2: Placebo
Intervention descriptions: intervention 1: Administered intravenously (iv) every 4 weeks intervention 2: Placebo to tocilizumab administered intravenously every 4 weeks

Protocol document: