The FDA has often been blamed for slowing the process of drug development. (An overview here.) There are plenty of problems with the FDA in its current form but this was a different take on the the problems confronting drug discovery:
“All of the 20,000 or so drug products that have ever been approved by the U.S. Food and Drug Administration interact with just two percent of the proteins found in human cells,” he [Brent Stockwell] writes in The Quest for the Cure. “This means the vast majority of proteins in our cells — many of which, in theory, can modulate disease processes — have never been targeted before with a drug.”
Many scientists, he says, have taken this as evidence that these harmful proteins yet to be penetrated by drugs cannot be stopped. Pharmaceutical companies have also succumbed to this viewpoint, he says, shifting their priorities away from the discovery of new drugs in favor of finding new applications for existing ones.
“Pharmaceutical companies face tough economic questions,” Stockwell says. “Should they spend their money going after proteins considered to be the most elusive? Or should they focus, perhaps, on fine-tuning their existing drugs in order to discover new clinical applications for them or to improve them just enough so that they can be marketed as new products?”