Investigational New Drug (Application):  the process by which a drug that is not yet licensed is approved for investigational use by the United States Food and Drug Administration (FDA).  Other countries have similar approval processes for investigational drugs which are frequently called Clinical Trial Applications (CTA) or Investigational Medicine Product Dossier (IMPD).


Orphan Drug:

A designation that may be granted by a regulatory agency such as the US FDA or the EMA that specifies certain allowances for drugs that are being developed for relatively rare diseases so that the needs of underserved populations may be addressed efficiently and safely.