The effectiveness of tocilizumab and its comparison with tumor necrosis factor alpha inhibitors for Takayasu Arteritis: A systematic review and meta-analysis

Takayasu arteritis (TAK) refractory to conventional disease-modifying anti-rheumatic drugs (DMARDs) is commonly treated with biologic DMARDs such as tocilizumab or tumor necrosis factor-alpha inhibitors (TNFi). The 2021 American College of Rheumatology (ACR) recommendations preferred TNFi to tocilizumab. Therefore, we conducted a systematic review with meta-analysis to assess the evidence base for tocilizumab in TAK by updating a previous systematic review on DMARDs in TAK through searches on MEDLINE, Pubmed Central, Scopus, major international Rheumatology conference abstracts, and clinical trial databases from January 2021 to November 2022. Thirty-five studies involving 1082 TAK [one randomized controlled trial (RCT), eleven controlled and twenty-one uncontrolled studies, most of moderate to high quality] had evaluated tocilizumab in TAK. The RCT of tocilizumab versus placebo failed to meet its primary end-point of superiority of tocilizumab on an intention-to-treat analysis (hazard ratio 0.41, 95%CI 0.15-1.10) but successfully met the secondary end-point of superiority on per-protocol analysis (hazard ratio 0.34, 95%CI 0.11-1.00). A meta-analysis of six studies identified similar rates of clinical remission [risk ratio (RR) tocilizumab vs TNFi 1.03, 95%CI 0.91-1.17)], angiographic stabilization (RR 1.00, 95%CI 0.72-1.40) or adverse events (RR 0.84, 95%CI 0.54-1.31) with tocilizumab or TNFi. A meta-analysis of three studies identified superior clinical response (RR 1.55, 95%CI 1.15-2.10) and adverse effect profile (RR 0.45, 95%CI 0.25-0.80) with tocilizumab than cyclophosphamide. Pooled data from uncontrolled studies identified clinical response in 85%(95%CI 79-91%) and angiographic stabilization in 82% (95%CI 68-94%). Our study suggests similar evidence for treating TAK with tocilizumab or TNFi, contrary to the ACR 2021 recommendations.