This brief essay examines data from the U.S. Orphan Drug Act, including specifically the FDA designations of an indication for a drug to treat an orphan disease, and the likelihood that once the designation is made, the FDA will approve the drug for that indication. This is one empirical measure of the risks associated with the development of new drugs to treat U.S. defined orphan diseases. Note that 75 percent of all novel cancer drugs approved in the United States from 2010 to 2016 qualified as orphan products. The essay also reports the average time between the FDA designation and the FDA approval for orphan indications.
The main findings are that since 2010, the average time from orphan designation to approval is 5.3 years, and the likelihood of FDA approval for an orphan indication, which varies over time and across business cycles, was .22 from 1990 to 2017, and since 2010, was .25.
The essay concludes with a comparison to other studies of the risks of drug development.
On January 5, 1983, the U.S. Orphan Drug Act became law as Public Law 97-414. Over the past 34 years the Act has been amended numerous times, often extending or expanding the benefits, which currently include a 50 percent tax credit for qualifying clinical trials, exemptions or discounts on prescription drug user fees, an easier and faster path to FDA approval, and seven years of marketing exclusivity for an approved orphan indication. Read More