A status given to certain drugs called orphan drugs, which show promise in the treatment, prevention, or diagnosis of orphan diseases. An orphan disease is a rare disease or condition that affects fewer than 200,000 people in the United States. Orphan diseases are often serious or life threatening. In 1983, the U.S. government passed a law, called the Orphan Drug Act, to give drug companies certain financial benefits for developing orphan drugs. This law is meant to help bring more drugs to patients with rare diseases.