Information on the comparative efficacy is important for drug development as well as drug therapy. Up to now, the relative efficacy of approved biologics and many agents under investigation in ankylosing spondylitis (AS) are still unclear. The objective of this study was to quantify the relative efficacy and time course of various treatments measured by the Ankylosing Spondylitis Assessment Study group response criteria 20 scores (ASAS20), change from baseline in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and Bath Ankylosing Spondylitis Functional Index (BASFI). There were 34 double-blinded trials of 10 biologics and small molecules encompassing 5,339 patients with AS were included in this analysis. Three mathematical models with nonparametric placebo estimations were used to describe the longitudinal profile for the above three efficacy measures. The results detected significant differences among included treatments, and infliximab and golimumab were found to have the highest efficacy in given dosage regimens across all measures.