Economic evaluation of subcutaneous versus intravenous immunoglobulin therapy in chronic inflammatory demyelinating polyneuropathy: a real-life study

Objectives: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired peripheral neuropathy of immunological origin with a clinical presentation and course that are extremely variable. The therapeutic approach generally includes corticosteroid drugs, intravenous immunoglobulins (IVIGs) or plasmapheresis alone or in combination as first line therapy, and immunosuppressants. In 2014 the Italian regulatory agency included subcutaneous immunoglobulins (SCIGs) in the list of off-label drugs reimbursed by the national health service. Our aim is to compare costs and outcomes of IVIG versus SCIG therapy.

Methods: Patients medical records and therapeutic plans were retrospectively analysed to collect data on IVIG treatments 1 year before the switch to SCIG, and after 1 year of treatment with SCIG. A budget impact analysis was conducted through resource identification and quantification, and healthcare and non-health care costs evaluation.

Results: 13 of 34 patients affected by CIDP who were referred to our neurophysiopathological unit and treated with IVIG were switched to home-based SCIG. After 1 year of receiving SCIG, 12 patients remained neurologically stable and reported good outcomes. Considering the cost of IVIG (€30.97/g) and adding to this the direct and indirect healthcare costs, the total cost of IVIG treatment for the 12 patients in a year was €371 417.06, compared with the cost of SCIG (€51.57/g) for a total annual cost of €631 745.16, not including indirect costs.

Conclusions: We observe a higher cost for SCIG treatment versus IVIG, which is not in line with data in the literature. However, SCIGs offer some important safety benefits and improvements in patient quality of life.