Background Orphan drugs mean a high economic impact and cost per patient, and in the past years there has been an increase in the number of patients.

Purpose To describe and analyse the evolution of spending on orphan drugs based on diagnosis.

Material and methods A retrospective study including all patients receiving treatment with orphan drugs from January 2013 to December 2015 was conducted. Collected parameters were: number of patients per drug, diagnosis, economic spending (€) and percentage of total and annual expenditure. Data were obtained through SAVAC, a prescription and validation programme; Discoverer, its complementary programme for exploitation of the data and a designed Excel base were used for data collection.

Results A total of 25 drugs were identified. Evolution from 2013 2015 is shown in the table.

Triennial analysis the distribution of total spending over the 3 years for diagnosis (€15 121 487) was: Pompe disease 28%, oncological diseases 27% and multiple myeloma 22%. Other expenditures were allocated to various diagnoses. Regarding drugs, lenalidomide was 25% of the total expenditure, followed by alglucosidase alpha (24%), and azacitidine, bretuximab and nilotinib (<10% for each). Regarding average cost per patient/year, Pompe disease involved a cost per patient of €357 419, followed by Gauche disease with €172 808, and myelodysplastic syndrome and multiple myeloma with €34 835 and €32 781, respectively.

Conclusion In the past 3 years there has been an increase in the number of patients prescribed orphan drugs. This has led to an increase of about €2 million with regard to cost per patient. Pompe disease, oncological diseases and multiple myeloma represented approximately 80% of the total expenditure of orphan drugs. Only 2 drugs (lenalidomida and alglucosidase alpha) represented about 50% of the total expenditure. Pompe disease represents one of the largest expenses every year, a limited number of patients and a high cost per patient/year.

No conflict of interest