Dangerous originally, repurposed safely
One reason for the low success rate of novel drug development is the high percentage of adverse side effects found in late-stage clinical trials. However, failed drugs can be repurposed for different diseases with new patient populations that would not be affected by such side effects, creating benefit for both pharmaceutical companies and for patients.
Most adults have heard about “thalidomide babies” born with birth defects in the 1950s. however, they might not know that this drug, developed as a treatment for morning sickness, has some redeeming qualities. While it was dangerous in its initial disease indication, this drug has been explored for its other properties and has been proven effective in the treatment of multiple myeloma, a devastating blood cancer (1) and the treatment of leprosy (2). Its approval for multiple myeloma by the FDA and regulatory agencies in other countries came more than 50 years after its initial approval. With current knowledge and technology it is possible to accelerate repurposing research for other drugs can lead to more stories like these in far less time.
2. Teo S1, Resztak KE, Scheffler MA, Kook KA, Zeldis JB, Stirling DI, Thomas SD.
Thalidomide in the treatment of leprosy. Microbes Infect. 2002 Sep;4(11):1193-202.