CFR > Title 21 - Food and Drugs > CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES > SUBCHAPTER D—DRUGS FOR HUMAN USE (parts 300 to 370) > PART 316—ORPHAN DRUGS > SUBPART E—Open Protocols for Investigations (§316.40 to §316.40) > 316.40—Treatment use of a designated orphan drug.