Background: New biologics have dramatically changed therapeutic options for psoriasis, albeit at additional cost.
Objectives: To determine the cost-effectiveness and optimal treatment sequence for moderate to severe psoriasis.
Methods: Psoriasis Area and Severity Index (PASI) response rates from 22 randomized controlled trials evaluating biologic (adalimumab, efalizumab, etanercept, infliximab) and nonbiologic systemic (methotrexate, ciclosporin) agents were considered. Short-term efficacy was based on relative probabilities of achieving PASI response (50/75/90) in a meta-analysis of trials. Published evidence and assumptions were used to predict long-term efficacy. Treatment benefits were determined by the relationship between PASI response and the EuroQOL 5D health utility measure. Costs included therapy, administration, monitoring and hospitalization. Incremental cost-effectiveness ratios (ICERs) were calculated and treatments ranked relative to supportive care.
Results: Infliximab provided the most incremental quality-adjusted life-years (QALYs) vs. supportive care (0.18 QALYs; 95% confidence interval, CI 0.13-0.24), followed by adalimumab (0.16 QALYs; 95% CI 0.11-0.22). Methotrexate and ciclosporin were less beneficial (0.13 and 0.08 QALYs, respectively) but were cost saving and considered the first two treatments in the optimal sequence. Comparing biologics, adalimumab was most cost effective (ICER pound30 000 per QALY), followed by etanercept ( pound37 000 per QALY), efalizumab ( pound40 000 per QALY) and infliximab ( pound42 000 per QALY).
Conclusions: Methotrexate and ciclosporin are cost effective but require monitoring for toxicities. Of the biologics, adalimumab was most cost effective following conventional systemic treatment failure or inadequate response. Payers and policymakers will have to decide how to utilize their budgets effectively for treating patients with moderate to severe psoriasis.