OBJECTIVES

Most governments provide preferential market treatment and exclusivity to successful “orphan drug” products for rare diseases. While drugs may be repurposed for rare disease indications, the same drug may be marketed under different trade names with the potential for differential pricing. This research investigates US prices for drugs sold under separate trade names for orphan and non-orphan indications.

METHODS

The US Food and Drug Administration Orphan Drug Product Designation Database was searched on January 1, 2021. Drugs were included if they had an approved orphan designation, were used as monotherapy, and had market exclusivity as of January 1, 2021. Drugs were researched to determine whether they had separate trade names for orphan and non-orphan designations, identified by trade name in the US Veterans Affairs National Acquisition Center Program Database, and compared for similar routes of administration. Federal Supply Schedule prices were subsequently extracted and compared on a per-month and cost/unit basis.

RESULTS

Six drugs (cabozantinib, denosumab, everolimus, hydroxyurea, peginterferon alfa-2b, and tolvaptan) have the same route of administration and different trade names for orphan and non-orphan indications. For one month of treatment, the ratios of prices between orphan and non-orphan indications were: 11.163 for denosumab, 7.724 for everolimus, 2.707 for hydroxyurea, 2.683 for peginterferon alfa-2b, 1.062 for cabozantinib, and 0.930 for tolvaptan (ratios >1 indicate higher cost for the orphan indication). Using the total dose administered in one month, the ratios of cost/unit prices between orphan and non-orphan indications were: 2.314 for cabozantinib, 1.655 for everolimus, 1.624 for hydroxyurea, 0.926 for denosumab, 0.748 for tolvaptan, and 0.453 for peginterferon alfa-2b.

CONCLUSIONS

While certain drugs are significantly more expensive when used in an orphan indication, others do not follow this same pattern. Further research is needed to explore additional drug databases in the US and other countries.