orphan drug

orphan drug (plural orphan drugs)

1. A medicinal drug which is effective in the treatment of some disease(s), but which is not manufactured or marketed because the demand is insufficient to cover the costs of supply.

   Tragically, her disease is so rare that the only effective medicine is an orphan drug.

2. (US, law) A drug as defined under the Orphan Drug Act (1983). (Can we add an example for this sense?)

• orphan disease