Pharmacology. a drug that remains undeveloped or untested or is otherwise neglected because of limited potential for commercial gain.
Origin of orphan drug
First recorded in 1975–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Any of various drugs or biologicals that may be useful in treating disease but are not considered to be commercially viable.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.