Continuous efficacy of etanercept in severe and advanced ankylosing spondylitis: results from a 12-week open-label extension of the SPINE study

Objective. To evaluate the longer-term efficacy of etanercept in patients with severe and advanced active AS. Methods. Seventy-seven patients who completed the randomized, double-blind, placebo-controlled 12-week SPINE study enrolled in a 12-week open-label extension and received s.c. etanercept 50?mg once weekly. The etanercept/etanercept group received a total of 24 weeks treatment with etanercept (n?=?38); the placebo/etanercept group received placebo during the double-blind study then 12 weeks' etanercept treatment during the open-label extension (n?=?39). Results. At the end of the open-label extension, BASDAI scores in the etanercept/etanercept group had further decreased beyond reductions observed during the double-blind study [mean (s.d.) change from baseline -37.6 (22.4) at end of extension vs -27.4 (23.8) at end of double-blind study]. Mean (s.d.) BASDAI scores also improved in the placebo/etanercept group once switched to etanercept [-28.6 (24.3) vs -15.0 (20.0)]. Similar trends were observed in BASFI and BASMI scores. In the placebo/etanercept group, total back pain decreased to similar levels achieved in the etanercept group in the double-blind study. Pain levels continued to decrease with longer-term etanercept therapy in the etanercept/etanercept group. Conclusion. Despite the improvements in symptoms and inflammatory markers observed shortly after initiation of once-weekly etanercept, there was no notable plateauing effect on patient-reported outcomes. Indeed, signs and symptoms of severe and advanced active AS continued to improve after up to 24 weeks, treatment with etanercept. Trial registration: ClinicalTrials.gov, http://clinicaltrials.gov/ct2/home, NCT00420238.