ADALIMUMAB REDUCES SPINAL AND SACROILIAC JOINT INFLAMMATION IN PATIENTS WITH ANKYLOSING SPONDYLITIS (AS)—52 WEEK MAGNETIC RESONANCE IMAGING (MRI) RESULTS FROM THE CANADIAN AS STUDY

Background: Significant spinal and sacroiliac (SI) joint inflammation is a characteristic of AS. This study evaluated the efficacy of adalimumab (ADA) vs. placebo (PBO) in reducing spinal and SI joint inflammation in MRIs among patients with active AS.Methods: This was a Phase III study conducted in Canada with a 24-week double-blind period during which patients were randomized to receive either ADA 40 mg every other wk (eow) or PBO. This was followed by an 80-week open label period where both ADA and PBO patients were administered ADA 40 mg eow. MRIs of the spine and SI joints were performed at Baseline (BL), Week 12, and Week 52. Inflammation was measured by the Spondyloarthritis Research Consortium of Canada (SPARCC) MRI Index.Results: A total of 82 patients (44 PBO, 38 ADA) were enrolled. Patients in ADA and PBO arms had similar baseline characteristics. The table displays the effects of ADA and PBO on spinal and SI joint inflammation.In those patients with available data, the reduction in both spinal and SI joint inflammation was sustained through Week 52. In the ADA group, the mean SPARCC scores at Week 52 were 6.2 for the spine (–50% change from BL, n=37) and 1.5 for the SI joints (–52% change from BL, n= 23). After Week 24, PBO patients were switched to open label ADA and had improved SPARCC scores that were comparable to the ADA patients by Week 52.Improvement in C-reactive proten (CRP) levels were also significantly associated with changes in spinal SPARCC score (p=0.018) within the ADA group. MRI Inflammation N BL Week 12 BL-Week 12 P Value* Measure/Arm Mean Value Mean % Change Spinal SPARCC PBO 41 19.9 18.6 -9% – Spinal SPARCC ADA 37 16.0 6.7 -54% <0.0001 SI Joint SPARCC PBO 29 7.5 6.4 -13% – SI Joint SPARCC ADA 24 5.7 2.1 -53% <0.0001 *Comparison of percent change from BL of ADA vs. PBO.Conclusion: Adalimumab significantly reduced spinal and SI joint inflammation in AS patients after 12 weeks of treatment; this improvement was maintained through 52 weeks. Reduction in CRP predicted improvements in spinal SPARCC scores in ADA patients at Week 12.Citation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 65Session: Diagnostics and imaging procedures