Clinical Features and Drug Retention of TNF Inhibitors in Older Patients with Ankylosing Spondylitis: Results from the KOBIO Registry

Abstract

OBJECTIVES: This study aimed to analyse the clinical features and outcomes of and reasons for discontinuing tumour necrosis factor (TNF) inhibitor therapy in older patients with ankylosing spondylitis (AS). METHODS: Data were extracted from the nationwide Korean College of Rheumatology Biologics registry. Clinical variables and outcomes were compared, and drug retention rate was evaluated. RESULTS: Among 1524 patients with AS treated with TNF inhibitors, 306 were aged >/= 50 years ('older patients'). Fewer patients were male, the incidence of hypertension and diabetes was higher (all p < 0.001), and the proportion of peripheral arthritis (35.6 vs. 27.1%), Ankylosing Spondylitis Disease Activity Score‒erythrocyte sedimentation rate (4.0 +/- 1.1 vs. 3.6 +/- 1.0), and Bath Ankylosing Spondylitis Functional Index (4.2 +/- 2.6 vs. 3.3 +/- 2.5) were all higher in older patients. Although the drug retention rate was lower (log-rank p = 0.018) and lack of efficacy and adverse events were more frequent in older patients (both p < 0.001), drug retention rates were not different after propensity score matching (log-rank p = 0.23). Improvements in disease activity and manifestations were comparable between groups, except for the incidence of peripheral arthritis, which decreased significantly less in older patients over 3 and 5 years. CONCLUSION: Improvements in disease-related clinical factors and drug retention rates were not different between older and younger patients with AS receiving TNF inhibitors. However, the incidence of adverse events was higher in older patients.