Maintenance of improvement in spinal mobility, physical function and quality of life in patients with ankylosing spondylitis after 5 years in a clinical trial of adalimumab

OBJECTIVE Chronic pain and progressive loss of physical function with AS may adversely affect health-related quality of life (HRQoL). The objective of this study was to assess the 5-year data regarding spinal mobility, physical function and HRQoL in patients with AS who participated in the Adalimumab Trial Evaluating Long-term Efficacy and Safety for AS (ATLAS) study. METHODS Patients received blinded adalimumab 40 mg or placebo every other week for 24 weeks, then open-label adalimumab for up to 5 years. Spinal mobility was evaluated using linear BASMI (BASMIlin). BASDAI, total back pain, CRP, BASFI, Short Form-36 and AS quality of life (ASQoL) were also assessed. Correlations between BASMIlin and clinical, functional and ASQoL outcomes after 12 weeks and after 5years of adalimumab exposure were evaluated using Spearman's rank correlation. Associations were further analysed using multivariate regression. RESULTS Three hundred and eleven patients received ≥1 dose of adalimumab; 125 of the 208 patients originally randomized to adalimumab received treatment for 5 years. Improvements in BASMIlin were sustained through 5 years, with a mean change of -0.6 from baseline in the population who completed 5 years of treatment with adalimumab. Improvements in disease activity, physical function and ASQoL were also sustained through 5 years. BASMIlin was significantly correlated with all evaluated clinical outcomes (P < 0.001). The highest correlation was with BASFI at 12 weeks (r = 0.52) and at 5 years (r = 0.65). Multivariate regression analysis confirmed this association (P < 0.001). CONCLUSION Treatment with adalimumab for up to 5 years demonstrated sustained benefits in spinal mobility, disease activity, physical function and HRQoL in patients with active AS. Spinal mobility was significantly associated with short- and long-term physical function in these patients. TRIAL REGISTRATION Clinicaltrials.gov; https://clinicaltrials.gov/NCT00085644.