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. Methods: To overcome the lack of knowledge concerning the actual cost effectiveness of biologic therapies for the treatment of plaque psoriasis in the clinical practice setting in Italy, an observational study was conducted in 12 specialist centres on patients switching to biologic therapy within a 6-month enrolment window. Results: The study confirms in clinical practice the efficacy of the switch to biologic therapies, analysed using a number of clinical [Psoriasis Area and Severity Index (PASI), pain visual analogue scale (VAS) and itching VAS] and quality-of-life parameters. A general health-related quality of life (HR-QOL) improvement, with a 0.23 quality-adjusted life-year (QALY) mean gain per patient, has been reported in the 6-month observation period. The direct medical costs to treat plaque psoriasis with biologic therapies amount to €15,073.7 per year (prior to their enrolment, the same patients cost €2,166.2 on an annual basis). After the switch to biologic agents, the cost per QALY during the first year of treatment amounts to €28,656.3. Conclusion: At least in the short-term, the clinical practice of the specialised Italian centres taking part in the study confirms that switching patients to a biologic drug produces an incremental cost-effectiveness ratio comparable with the values predicted by the HTA bodies