The Orphan Drug Act extends exclusivity of branded drugs by 7 years for each rare disease approval.

A new study finds that drugmakers are utilizing orphan drug exclusivities to extend market dominance and keep generics and biosimilars off the market.

Researchers analyzed a retrospective cohort of FDA orphan drug approvals filed between 1983 and 2017, and respective costs throughout this time period using IQVIA claims data.

A total of 432 branded drugs were approved for 615 orphan indications, of which 108 had multiple indications. The potential budget impact of additional market-exclusivity was estimated at $591 billion for 7 years.

While authors concluded that limiting market exclusivity would save billions, they also questioned whether six-hundred billion is the price-tag of innovation and development of orphan drugs.