The cost effectiveness of biologic therapy for the treatment of chronic plaque psoriasis in real practice settings in Italy.

Background and Objectives Biologic therapies are considered to be cost effective by leading Health Technology Assessment (HTA) agencies and, therefore, eligible for reimbursement by public health services. However, biologic therapies entail sizable incremental costs and, besides, have a considerable financial impact that in Italy amounts to 13.7 % of the national health service’s pharmaceutical expenditure. In the reimbursability decision process, an important role is played by both the drug efficacy data observed in pre-licensing RCTs and the economic modelling assumptions, as they give evidence on cost effectiveness. The administration of therapies in real practice settings is likely to produce a significant deviation from the results predicted by the models, theoretically outweighing the assumption on which the decision process is founded. This is a matter of concern for public health services and, consequently, an interesting topic to investigate.