LIVERPOOL, ENGLAND — The majority of patients with ankylosing spondylitis being treated with anti-tumor necrosis factor agents in a routine care setting experienced improvements in disease activity after 6 months of treatment, according to Dr. Paul A. Lord of the University of Manchester (England).
Clinical trials have demonstrated the efficacy of these biologic drugs in ankylosing spondylitis (AS), but few data exist regarding the effectiveness in a real world setting.
Accordingly, the British Society for Rheumatology's Biologics Register began recruiting AS patients in 2002, recording baseline demographics, disease duration, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) scores, as well as current and former drug treatments.
A total of 572 patients have been recruited, and data have now been analyzed for 261, with the primary outcome being changes in BASDAI and BASFI scores at 6 months.
The patients were predominantly young, with a median age of 43 years, and 81% were male. The median baseline BASDAI score was 7.6 and the median baseline BASFI score was 7.9. “They had severe disease,” Dr. Lord said at the annual meeting of the British Society for Rheumatology.
At 6 months, mean improvements of 3.5 and 2.7 U, respectively, were seen on BASDAI and BASFI. Additionally, 71% had improvements on BASDAI of at least 2 U, and 52% achieved a BASDAI 50 response, which represents a major clinical response, he said.
The first TNF blocker given was etanercept in 57%, infliximab in 36%, and adalimumab in 7%. Conventional disease-modifying antirheumatic drugs (DMARDs) also were being used by 54% and 55% of those on infliximab and adalimumab, respectively, compared with 37% of those on etanercept.
Lesser responses were seen in those with higher baseline BASFI scores, and women had a 1-U greater improvement on BASFI at 6 months compared with men.
Concurrent use of DMARDs was associated with improved functional status, demonstrated by a 0.8-U greater improvement on BASFI compared with those on monotherapy, but was not associated with absolute change in BASDAI.
Patients whose inflammatory markers were elevated at baseline had a 0.9-U greater response than those whose ESR and CRP level were normal at baseline, suggesting that these patients may be more responsive to anti-TNF therapy, Dr. Lord said.
Although the patients with baseline inflammatory markers had a better response to anti-TNF therapy, the benefits were not confined to this group, he noted.
Dr. Lord and his colleagues from the biologics register have reported no conflicts of interest.