Cost-efficacy of adalimumab, etanercept, infliximab and ustekinumab for moderate-to-severe plaque psoriasis

Background Different biological agents are used for the treatment of psoriasis. Previous data have shown adalimumab to be the most efficient drug in terms of cost-efficacy. However, newer data are required to include recent drugs. Objective To estimate the cost-efficacy ratios of biological agents licensed in Spain (adalimumab, etanercept, infliximab and ustekinumab) for the treatment of patients with moderate-to-severe psoriasis. Methods An economic evaluation model was developed by building a decision tree for each drug regimen for which scientific evidence was available. The payer perspective (Spanish National Health System) was considered, taking into account only the drug costs. Data on efficacy [proportion of patients with a 75% reduction in the Psoriasis Area and Severity Index score (PASI 75)] reported in the randomized controlled trials were used. When more than one trial for each treatment had been published, a meta-analysis was performed. In case of weight-dependent doses (infliximab), weight of the study subjects was standardized by age and gender of the Spanish population, corrected for the increase in weight in subjects with psoriasis. Uncertainty was assessed by sensitivity analysis. Results Incremental efficacy ranged from 31.19% (etanercept at a dosage of 25 mg twice a week for 12 weeks) to 78.35% (infliximab at 5 mg/kg for 24 weeks). Efficiency, in terms of incremental cost-efficacy, ranged from 8013 pound (adalimumab) to 17 981 pound (ustekinumab at a dose of 90 mg) per PASI 75 responder gained. Conclusion In terms of cost-efficacy, the most efficient biological drug was adalimumab. The robustness of this finding was confirmed by sensitivity analysis.