ADALIMUMAB REDUCES INFLAMMATION IN THE SACROILIAC JOINTS OF PATIENTS WITH ACTIVE SPONDYLOARTHRITIS WITHOUT RADIOGRAPHIC SACROILIITIS — RESULTS OF A PLACEBO-CONTROLLED, DOUBLE-BLIND CLINICAL TRIAL THROUGH 52 WEEKS

Background: Adalimumab is very effective in improving the signs and symptoms of active axial spondyloarthritis. No data are currently available on the course of the active inflammatory lesions in the sacroiliac (SI) joints as detected by magnetic resonance imaging (MRI) in patients with active spondyloarthritis without radiographic sacroiliitis. Objectives: We investigated SI joint inflammation at baseline, Week 12, and Week 52 in patients with active spondyloarthritis without radiographic sacroiliitis who were included in a placebo-controlled, double-blind trial of adalimumab. Methods: MRI investigations were conducted for patients at 2 centers in Germany enrolled in a 12-week, placebo-controlled trial with a 40-week, open-label extension. Adult patients with active SpA (BASDAI ≥4) and insufficient responses to ≥1 prior NSAIDs were included in this study. MRIs of the SI joints were performed at baseline, Week 12 and Week 52. Active inflammation in the SI joints was scored according to Hermann et al., with each SI joint divided into quadrants and with modifications for additional points of intensity for each SI joint (range: 0–34). MRIs were scored independently by 2 readers blinded to time points of the MRIs. Mean scores of the 2 readings were included in the analysis. Results: Of the 37 patients with complete MRI data for the SI joints at baseline, 84% had a SI joint score ≥1; 78% had ≥2, and 24% had a score ≥10 (reflecting extended SI joint inflammation). Of the 19 patients with complete MRI data for baseline and week 12, mean SI joint score changed from 11.8 at baseline to 10.5 (median: 6.5 to 8.5) at Week 12 for the placebo group (n=9) and from 3.9 to 2.5 (median: 3.3 to 1.3) for the adalimumab group (n=10), p>0.05 (not significant) for both groups. Of 28 patients with complete MRI data for baseline and Week 52, the mean SI joint score changed from 10.1 to 4.3 (median: 6 to 2) for the initial placebo group (n=16), p=0.012, and from 4.8 to 3.0 (median: 3.25 to 3) for the adalimumab group (n=12), p>0.05 (not significant). For the pooled group, there was also a significant improvement from 7.9 at baseline to 3.8 (median: 5.3 to 3) at Week 52 (p=0.003). Of the pooled group of patients, 18% had a score of 0 at Week 52, reflecting no inflammation of the SI joints, and 54% had an MRI improvement of >50%. A score of ≥2 at Week 52 was found in 61% of patients. Inter-reader correlations were substantial: 0.88 at baseline, 0.91 at Week 12, and 0.88 at Week 52. Conclusion: Of patients with active axial spondyloarthritis without radiologic sacroiliits in this study, the majority had inflammatory lesions as detected by MRI in the SI joints, and a substantial number of patients also had extensive SI joint inflammation. Adalimumab therapy significantly improved inflammation as observed by MRI for patients treated for 1 year. References: 1. Haibel H, et al. Arthritis Rheum. 2008;58:1981-91. 2. Hermann KG, et al. Radiologe. 2004;44:217-28. Disclosure of Interest: H. Haibel, Abbott, Scherring Plough, Speakers fees X. Baraliakos, Abbott, Consultant M. Rudwaleit, Abbott, MSD, Schering-Plough, Pfizer, and Wyeth, Consultancies, speaking fees, honoraria J. Listing, Abbott, Consultant R. Wong, Abbott, Employee, stocks H. Kupper, Abbott, Employee, stocks J. Braun, Abbott, Schering-Plough, Wyeth, Centocor, Amgen, Reiumbursements, fees, grant J. Sieper, Abbott, Schering-Plough, Wyeth, Research grants, Abbott, BMS, Roche, Schering-Plough, Wyeth, Consulting fees or other remuneration, Abbott, Roche, Pfizer, Scheering-Plough, Wyeth, Speakers bureauCitation: Annals of the Rheumatic Diseases, volume 68, supplement 3, year 2009, page 628Session: Spondylarthropathies Treatment (Poster Presentations )