"You might expect these existing special programs to represent a small fraction of new and unusual drugs. But data from the Food and Drug Administration show that a majority of recent drug development has been in therapies that qualify for at least one of these programs. About a third of recently approved drugs qualify for two or more of five special approval programs."
"Dr. Kesselheim, an associate professor of medicine at Harvard Medical School, said the popularity of the expedited programs could be worrisome; the expedited pathways typically require less evidence of a drug’s efficacy or safety than the standard process."
From http://ow.ly/Myj0X :
Speedy Drug Approvals Have Become the Rule, Not the Exception
Most recent drug development in the U.S. has been done through specially approved pathways, and two more may be added.