Assessing the Quality and Coherence of Network Meta-Analyses of Biologics in Plaque Psoriasis: What Does All This Evidence Synthesis Tell Us?

Introduction: A range of treatments are available for moderate-to-severe psoriasis; however, there remains a paucity of direct comparisons of these in head-to-head trials. Network meta-analyses (NMA) allow comparisons of these to support clinical decision making. This systematic literature review assesses the methodological quality of NMAs available for moderate-to-severe psoriasis and compares their methods and results. Their validity and applicability for current practice is also assessed.

Methods: A systematic review of published NMAs of at least two biologics for moderate-to-severe psoriasis was undertaken. Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Library were last searched on 19 February 2020. The quality of NMAs was assessed using the International Society of Pharmacoeconomics and Outcomes Research (ISPOR) criteria. NMA methodology, funding, and results were compared and differences in results explored.

Results: Twenty-five analyses evaluating up to 19 different treatments at 8-24 weeks, and two analyses at 1 year, were included. Psoriasis Area Severity Index (PASI) response was assessed in 23, facilitating comparisons between NMAs. All NMAs met at least half of the ISPOR criteria. The major limitations were explaining the rationale for methodology, exploring effect modifiers, and consistency between direct and indirect estimates. The analyses differed in model type (Bayesian or frequentist), analysis of PASI response (binomial or multinomial), and analysis of different treatment doses (separate or pooled). PASI results were broadly similar, except for the Cochrane Collaboration NMA which provided lower estimates of treatment efficacy versus placebo. This analysis differed methodologically from others, including pooling data for different doses.

Conclusions: Based on PASI 90 at induction, the majority of recent NMAs came to similar conclusions: interleukin (IL) 17 inhibitors (brodalumab, ixekizumab, secukinumab), IL-23 inhibitors (guselkumab and risankizumab) and infliximab were most efficacious, supporting the validity of NMAs in this clinical area. Decisions should be made using high-quality, up-to-date NMAs with assumptions relevant to clinical practice.