Network Meta-Analysis and Cost Per Responder of Tumor Necrosis Factor-α and Interleukin Inhibitors in the Treatment of Active Ankylosing Spondylitis

Introduction: Biologic therapies have improved the clinical management of ankylosing spondylitis (AS). Few head-to-head studies have directly compared the efficacy of these agents. This study was conducted to indirectly compare the efficacy of biologic agents for treatment of active AS.

Methods: A targeted literature review was conducted to identify randomized clinical trials for adalimumab, infliximab, golimumab, certolizumab pegol, etanercept, and secukinumab for the treatment of active AS. The clinical efficacy was evaluated using ASAS20 and ASAS40 and synthesized via a Bayesian network meta-analysis. Number needed to treat (NNT) was calculated as the reciprocal of incremental response rate of each biologic versus placebo. Comparisons were also made in terms of cost per incremental ASAS20 or ASAS40 responder.

Results: Fifteen studies were identified, which included ASAS20 and/or ASAS40 response rates at Week 12 to Week 16. Patients with AS treated with infliximab had the lowest NNT for ASAS20 of 2.3, followed by those treated with adalimumab (2.8) and etanercept (2.9). Adalimumab had the lowest 12-week cost per additional ASAS20 responder at $26,888, followed by infliximab at $28,175 and golimumab at $28,199. Patients treated with infliximab also had the lowest NNT for ASAS40 (2.6), followed by those treated with adalimumab (2.8) and secukinumab (3.5). Adalimumab had the lowest cost per additional ASAS40 responder at $26,898, followed by infliximab at $32,508 and etanercept at $34,406.

Conclusion: Infliximab had the lowest NNT to achieve an additional ASAS20/40 response, and adalimumab had the lowest cost per ASAS20/40 responder among biologic agents for the treatment of active AS.

Funding: AbbVie.