AB0662 Indirect Comparison of TNF Inhibitors for Ankylosing Spondylitis and Non-Radiographic Axial Spondyloarthritis: Meta-Analysis of Randomized, Double-Blind, Placebo-Controlled Trials

Background For ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA) patients, tumor necrosis factor (TNF) inhibitors are recommended when disease activity persists despite non-steroidal anti-inflammatory drugs. Objectives To evaluate the efficacy and safety of TNF inhibitors in patients with AS and nr-axSpA. Methods Searching PubMed, Embase, Cochrane Library, CNKI and WanFang databases, we included all double-blind randomized controlled trials (RCTs) that compared a TNF inhibitor with placebo in AS/nr-axSpA patients. The efficacy endpoints included the proportions of patients reaching Assessment in Ankylosing Spondylitis 20% response (ASAS20), ASAS5/6, partial remission, and Bath Ankylosing Spondylitis Disease Activity Index 50% improvement (BASDAI50). We used adverse events (AEs), withdrawals due to AEs and severe AEs to evaluate the safety of biologics. TNF inhibitors were pooled to perform comparison with placebo and among themselves, calculating odds ratios (OR) with associated 95% credible intervals (CrI), probability of being best (P best ) and the surface under the cumulative ranking curve (SUCRA) as well as numbers needed to treat (NNT). Results Twenty-nine double-blind RCTs with 5200 patients were included in the analysis focusing on 6 TNF inhibitors, including etanercept, intended copies of etanercept, adalimumab, infliximab, golimumab and certolizumab. Compared with placebo, TNF inhibitors were efficacious in achieving ASAS20, ASAS5/6, partial remission and BASDAI50 responses, but with an increased risk of AEs and withdrawals due to AEs. No significant differences in efficacy were found among biologics, except that etanercept had a higher rate of ASAS20 response compared with golimumab in the Chinese patients (OR 4.78, 95% CrI 1.20–17.84). Among the Chinese population, etanercept was ranked the most efficacious therapy for ASAS20 with NNT of 2 (P best 93.6%, SUCRA 0.97). Conclusions Compared to placebo, TNF inhibitors are efficacious in controlling disease activity for AS and nr-axSpA patients without a higher risk of severe AEs. Although no significant differences in efficacy among biologics were found, the Chinese population had a better ASAS20 response to etanercept. References Ward MM, Deodhar A, Akl EA, et al. American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 Recommendations for the Treatment of Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis. Arthritis care & research 2015. Rudwaleit M, Haibel H, Baraliakos X, et al. The early disease stage in axial spondylarthritis: results from the German Spondyloarthritis Inception Cohort. Arthritis and rheumatism 2009;60:717–27. Maxwell LJ, Zochling J, Boonen A, et al. TNF-alpha inhibitors for ankylosing spondylitis. The Cochrane database of systematic reviews 2015;4:Cd005468. Callhoff J, Sieper J, Weiss A, et al. Efficacy of TNFalpha blockers in patients with ankylosing spondylitis and non-radiographic axial spondyloarthritis: a meta-analysis. Annals of the rheumatic diseases 2015;74:1241–8. Disclosure of Interest None declared