Drug Repurposing for Rare (Orphan) Diseases—Scope and Limitations

Effective and affordable treatment for rare diseases remains a huge challenge. Only a few drugs have made inroads into the therapeutic arena for rare diseases. The current focus is shifted to different uses for expensive new drugs, referred to as drug repurposing. It is also called drug repositioning or reprofiling, refers to the identification of new therapeutic applications of existing or investigational drugs. This concept and novel approaches have promising role in the treatment of many potentially incurable diseases, particularly certain forms of cancer, neurodegenerative conditions, immunological disorders and uncommon infectious diseases. There are huge expectations filled with optimism that the drug repurposing would offer fresh opportunities for the treatment and management of rare diseases. This is undoubtedly more relevant for low and middle income countries.