Indirect comparisons of the efficacy of biological agents in patients with active ankylosing spondylitis: a systematic review and meta-analysis

Patients with ankylosing (AS) often do not have a satisfactory response to, or could not tolerate, non-steroidal anti-inflammatory drugs (NSAIDs). Several biologic agents are available for such patients. However, the comparative efficacy of these treatments remains unknown as head-to-head randomized controlled trials (RCTs) are not available. RCTs examining the efficacy of biologic agents in patients with AS who had inadequate response to, or could not tolerate, NSAIDs were identified. If at least two RCTs were available for a given biologic agent, the pooled odds ratio (OR) and 95% confidence interval (CI) of achieving 20% improvement according to the Ankylosing Spondylitis Assessment Study group response criteria 20 (ASAS20) across trials were calculated. The pooled OR for each biologic agent was then compared to each other using the indirect comparison technique. A total of 14 RCTs of older TNF inhibitors, two RCTs of secukinumab, one RCT of certolizumab, and one RCT of tofacitinib were identified. No significant difference in any indirect comparisons was observed with the p values ranging from 0.12 to 0.74. The likelihood of achieving the ASAS20 response in patients AS who failed or could not tolerate NSAIDs was not significantly different between older TNF inhibitors, secukinumab, certolizumab, and tofacitinib. However, the analysis is limited by the small sample size with only one RCT for certolizumab and tofacitinib.