Treatment of Axial Spondyloarthritis by Recombinant Human Tumor Necrosis Factor-α Receptor Ⅱ IgG Fc Fusion Protein

This is a randomized, double-blind, multicentral clinical trial to investigate the efficacy and safety of Recombinant Human Tumor Necrosis Factor-α Receptor Ⅱ IgG Fc fusion protein injection (Yisaipu®) in the treatment of active axial spondyloarthritis(SpA). The primary purpose is to assess the different situations in maintaining treatment programme in SpA patients with controlled inflammation by Yisaipu®. And the second purpose is to assess the eficacy and safety of Yisaipu® in axial SpAs. The trial will include 150 patients with stable NSAIDs therapy, and at the first stage they will receive 24-week full-dose of Yisaipu®. Then at the second stage the patients who achieve low disease activity (LDA, ASDAS\<2.1) at 24th week will be randomizedly divided into three group: full-dose of Yisaipu® group, half-dose of Yisaipu® group and placebo group. And the blind stage will last for 48 weeks. Patients who complete the 72-week therapy or achieve disease-flare criteria during the blind stage would finish the study.