OBJECTIVES: Luxembourg, one of the smallest European Union member states, with a gross domestic product per capita twice that of Belgium, tends to informally follow drug pricing decisions of Belgium. Lengthy negotiations and duplication of heath technology assessment work are prevented by following this procedure. The aim of this study was to test the applicability of this hypothesis on orphan drugs (ODs) by comparing their annual cost in Belgium and Luxembourg.

METHODS: The list of ODs approved in Europe up until 01/03/2018 was extracted from European Medicine Agency (EMA) website. OD annual treatment prices in both countries were calculated based on ex-factory prices extracted from IHS POLI database and the posology described in summary of products characteristics. The ratio of OD prices were calculated in Belgium taking Luxembourg as the reference.

RESULTS: Out of 102 ODs authorized in Europe, 44 had available prices in Belgium and Luxembourg. The annual OD prices were strongly homogeneous as the ratio of prices between the two countries ranged from 0.81 to 1.39 with an average ratio of 0.99 (±0.08) and a median of 1.00. Twenty-nine out of 44 ODs (66%) had exactly the same annual price in the two countries. Ten ODs had an annual treatment cost slightly higher in Luxembourg compared to that in Belgium (Decitabine, Olaratumab, Ixazomib, Venetoclax, Bosutinib, Daratumumab, Macitentan, Brentuximab Vedotin, Thalidomide, Nilotinib); while only 5 ODs had a slightly lower treatment cost (Tafamidis, Nintedanib, Rufinamide, Eliglustat, Riociguat).

CONCLUSIONS: This study shows that OD annuals costs tend to be the same in Belgium and Luxembourg. This homogeneity in OD prices may be explained by the strong willingness of Luxembourg to adopt Belgium as the reference country when setting prices. Rarity of the disease is not an exception to Luxembourg rule on HTA and pricing.