Clinical Efficacy of Etanercept Versus Sulfasalazine in Ankylosing Spondylitis Subjects with Peripheral Joint Involvement

Abstract

Etanercept, a fully human tumor necrosis factor soluble receptor, is effective in treatment of ankylosing spondylitis (AS). Current guidelines suggest sulfasalazine (SSZ) treatment as initial therapy for the management of patients with AS with peripheral arthritis versus therapy with biologics. We compared the efficacy of etanercept with SSZ in patients with AS with peripheral joint involvement. The efficacy of etanercept 50 mg once weekly was compared with that of SSZ up to 3 g daily in subjects with ≥ 1 swollen peripheral joint at baseline, using data from a 16-week randomized double-blind study in subjects with AS. Efficacy was assessed by the Assessment in AS criteria and the Bath AS Disease Activity, Functional, and Metrology indices. The last observation carried forward method was used for imputation of missing values. Of 566 subjects included in original study, 181 (etanercept 121; SSZ 60) had ≥ 1 swollen peripheral joint and 364 (etanercept 250; SSZ 124) had none at baseline. AS patients treated with etanercept showed significantly greater improvement than those treated with SSZ in all joint assessments regardless of swollen joint involvement. In this analysis, etanercept was significantly more effective than SSZ for management of patients with AS and peripheral joint involvement.