A classification for medications uses to treat rare medical conditions. This status offers financial incentives to drug manufactures who may not see significant return on researching these drugs. In many countries, it is a matter of public policy to develop orphan drugs.

See also:
Drug usage/utilisation review (DUR)
New Drug Application (NDA)
Off-label use
Open-label trial
Over the counter (OTC)
Research and development (R&D)