Drug Repositioning

• Drug repositioning is the process of identifying novel therapeutic potentials for existing drugs and discovering therapies for untreated diseases.
• Has the potential for discovering new drugs and additional uses for existing drugs
• aka Drug Repurposing, Drug reprofiling, Drug Redirecting, Drug retasking, Therapeutic switching
• Faster than traditional drug development approach
• traditional drug repositioning studies focus on uncovering drug effect and mode of action (MoA) similarities, revealing novel drug indications by screening the current pharmacopoeia against new targets, investigating prevalent characteristics between drug compounds such as chemical structures and side effects, or discovering the relationships between drugs and diseases.
• Drug repositioning Principles
  1. Drug related to specific disease may also work on other diseases (interdependence of diseases)
  2. Drug can be associated with various targets and pathways since drugs are confounding[^1] in nature
• Drug Repositioning Approaches
  1. Drug based strategies
     • Substantial drug related data is accessible
     • if two drugs, R1 and R2 have similar profile and mode of action, and drug R1 is used to cure disease D, then drug R2 can be considered as a strong candidate for treating disease D
     • Two Major Strategies Genome strategy & chemical structure and molecule information strategy
  2. Disease based strategies
     • Depend on data related to diseases such as phenotypic traits information, side effects, and indications information as the foundation to predict therapeutic potentials and novel indications for existing drugs.
     • if two diseases, D1 and D2 have a similar profile and indications, and drug R is used to cure disease D1, then drug R can be considered as a strong candidate for curing disease D2.
     • Strategy used : phenome strategy

[^1]: Confounding - mix up (something) with something else..