An orphan disease is defined by the Orphan Drug Act as a "condition that affects fewer than 200,000 persons in the United States."

Orphan diseases are diseases that are so rare that without an exceptional occurrence, little research might be done about them because of the lack of financial incentive.

The movie "Lorenzo's Oil" tells the true story of a child with an orphan disease, adrenoleukodystrophy, whose parents researched, raised money and together with scientists they interested in the project developed an effective therapy for the disease.

In 1982, the US Congress passed legislation to encourage companies to research and market drugs and biologicals for orphan diseases. Sponsors submit applications to the FDA for orphan designation and if granted are given significant financial incentives.

Since the act was signed, the FDA has approved 917 orphan products--including drugs and biologics. Sponsors have submitted 1,252 applications for orphan designation. Not all were approved. Orphan designation allows a company to proceed with development and take advantage of the law's financial incentives. Some of the products that have been approved since the law was passed were developed by large pharmaceutical companies but others have been developed by small companies whose very existence depends on the financial incentives provided by the Orphan Drug Act. Orphan law helped to establish the American biotechnology industry by allowing 7 years of exclusive marketing (akin to a patent) in some areas. Without such protection many small companies might not have developed biotechnology because other methods of protecting their financial interests did not exist. It seems many orphan diseases respond well to bio-tech solutions.