Study of Apremilast to Treat Subjects With Active Ankylosing Spondylitis (POSTURE)

• Assessment in Ankylosing Spondylitis (ASAS 20) [ Time Frame: Up to 16 weeks ] [ Designated as safety issue: No ]
  ASAS 20 at Wk 16
  
  

• Change from baseline in Bath Ankylosing Spondylitis Functional Index (BASFI) [ Time Frame: Up to 24 weeks ] [ Designated as safety issue: No ]
  Change from baseline in Bath Ankylosing Spondylitis Functional Index (BASFI)
  
  
• Change from baseline in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) [ Time Frame: Up to 24 weeks ] [ Designated as safety issue: No ]
  Change from baseline in Bath Ankylosing Spondylitis Disease Activity Index(BASDAI)
  
  
• Assessment in Ankylosing Spondylitis (ASAS 20) [ Time Frame: Up to 24 weeks ] [ Designated as safety issue: No ]
  Assessment in Ankylosing Spondylitis (ASAS 20)
  
  
• Change from baseline in the Physical Component Summary score (PCS) of Medical Outcome Study Short Form 36-Item Health Survey, Version 2 (SF-36) [ Time Frame: Up to 24 weeks ] [ Designated as safety issue: No ]
  Change from baseline in the Physical Component Summary score (PCS) of Medical Outcome Study Short Form 36-Item Health Survey, Version 2 (SF-36)
  
  
• Change from baseline in Bath Ankylosing Spondylitis Metrology Index-linear (BASMI-lin) [ Time Frame: Up to 24 weeks ] [ Designated as safety issue: No ]
  Change from baseline in Bath Ankylosing Spondylitis Metrology Index-linear (BASMI-lin)
  
  

Patients will be assigned two different treatments based on chance (randomized) to placebo or apremilast (20 or 30 mg tablet). The duration of the study is approximately 5 years. The double blind period (when patients nor the physician knows whether placebo or apremilast is taken) is 24 weeks. At Week 16, subjects who do not have either a ≥ 20% improvement or a ≥ 1 unit improvement from baseline in at least two of the four SpondyloArthritis international Society (ASAS) domains will enter the "early escape" from their current treatment in a double-blinded manner. However, such subjects will be permitted to continue in the study. At Week 24, subjects may enter a long-term extension phase for up to an additional 4.5 years (236 weeks). At "second escape" (at Week 24), apremilast 20 mg BID treated subjects will be transitioned to receive double-blinded apremilast 30 mg BID; apremilast 30 mg BID will remain on double-blinded apremilast 30 mg BID because they may continue to improve with a longer duration of treatment. After Week 24 and during the early portion of the long-term extension through Week 52, all subjects will continue on either double-blinded apremilast 20 mg BID or 30 mg BID treatment. After all subjects have completed Week 52 or have terminated early from the study and the 52-week data base is locked, open-label apremilast 20 mg BID or 30 mg BID treatment will be provided.