orphan drug
n.β Β«Some of the most successful blockbuster drugs in the world treat diseases that most people have never heard of. Theyβre called orphan drugs, and the government doles out big tax breaks to companies that deliver them. Even without the tax incentives, plenty of biotechs have found ways to profit big off drugs for rare diseases.Β» ββCashing in on βorphansβ” by Aaron Smith CNN Mar. 13, 2007. (source: Double-Tongued Dictionary)