A Randomized, Double-blind, Placebo-controlled, Phase III Study of Efficacy and Safety of GR1501 in Patients with Radiographic Axial Spondyloarthritis

This is a randomized, double-blind, placebo-controlled, multicenter clinical study to evaluate the efficacy and safety of GR1501 injection in Radiographic Axial Spondyloarthritis, as well as a confirmatory clinical trial of immunogenicity. This clinical trial was divided into four stages, namely screening period (W-4\~W0), core treatment period (W0\~W16), maintenance treatment period (W16\~W32), and follow-up period (W32\~W48). target population： radiographic axial spondyloarthritis who had a inadequate response to NSAIDs or have a history of intolerance to NSAIDs. primary outcome measure:percentage of participants achieving an ASAS20 response in week 16.