• Degree of structural damage (radiographic progression)after 4 and 6 years of infliximab therapy (2 years of ASSERT trial plus 2 years of EASIC trial) [ Time Frame: November 2008 and November 2010 ] [ Designated as safety issue: No ]
  

• Proportion of patients which have received anti-TNF-alpha therapy as standard care after the end of ASSERT [ Time Frame: November 2005 ] [ Designated as safety issue: No ]
  
• Description of the various treatment regimens after the end of ASSERT of the participating AS patients in various countries [ Time Frame: November 2005 ] [ Designated as safety issue: No ]
  
• Degree of spinal inflammation analyzed by MRI after discontinuation of infliximab and 4-8 weeks and 2 and 4 years after re-treatment [ Time Frame: November 2010 ] [ Designated as safety issue: No ]
  
• Long-term efficacy of infliximab over 4 and 6 years of therapy measured by the ASAS response criteria [ Time Frame: November 2010 ] [ Designated as safety issue: No ]
  
• Efficacy and safety of a new start of infliximab therapy after discontinuation for several months after 2 and 4 years of continuous treatment [ Time Frame: November 2008 and November 2010 ] [ Designated as safety issue: Yes ]
  
• Long-term effects on QoL [ Time Frame: November 2010 ] [ Designated as safety issue: No ]
  
• Long-term effects on health resource utilisation and productivity in paid and unpaid work [ Time Frame: November 2010 ] [ Designated as safety issue: No ]
  

Drug: infliximab
Infliximab infusions 5 mg/kg body-weight each 6 to 8 weeks

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown etiology that involves the sacroiliac joints, axial skeleton, entheses and peripheral joints. Chronic inflammation of entheses leads to new bone formation, syndesmophytes and ankylosis of joints, primarily in the axial skeleton. This leads to a dramatic loss of range of motion and to disability. The disease may also have nonskeletal manifestations including uveitis, carditis, pulmonary fibrosis and cardiac conduction abnormalities.

Current therapy for AS is mainly with NSAIDs and physiotherapy which are often insufficient. Clinical outcome with conventional therapies has not been good, with 50-70% of patients progressing to fusion of the spine by 10 to 15 years. Treatment with the TNF-alpha blocking agent infliximab was shown to have definite clinical efficacy in patients with active ankylosing spondylitis on a short- and a long-term basis over 2 years.

There is limited data available on the efficacy and safety of long-term anti-TNF therapy for 3 and more years, the outcome after discontinuation of anti-TNF therapy and the effect of anti-TNF therapy on radiographic progression over a long period of time.

The ASSERT trial was a 2 year international randomized placebo controlled trial to evaluate the efficacy and safety ot treatment with infliximab in patients with active and severe AS. The EASIC trial is initiated to follow the European participants of the ASSERT trial for at least an additional 2 years of treatment combined with systematic data collection.