Drug repurposing: a promising tool to accelerate the drug discovery process

Abstract

Traditional drug discovery and development involves several stages for the discovery of a new drug and to obtain marketing approval. It is necessary to discover new strategies for reducing the drug discovery time frame. Today, drug repurposing has gained importance in identifying new therapeutic uses for already-available drugs. Typically, repurposing can be achieved serendipitously (unintentional fortunate observations) or through systematic approaches. Numerous strategies to discover new indications for FDA-approved drugs are discussed in this article. Drug repurposing has therefore become a productive approach for drug discovery because it provides a novel way to explore old drugs for new use but encounters several challenges. Some examples of different approaches are reviewed here.

FIGURE 1

A comparison of traditional drug discovery process versus drug repurposing. The traditional drug discovery process is time consuming and involves a large financial burden on the innovators. By repurposing a drug, precious years can be cut down from a typical drug discovery cycle. Repurposing abolishes all the steps needed for FDA approval. Also, once the drug is FDA approved, Phase I of clinical trials can be eliminated, which saves a lot of time, effort and money involved in the studies. A short path can be followed to innovate a new system for clinical use using drug repurposing strategies.

FIGURE 2

A schematic representation of strategies that can be used for repurposing a drug. These strategies can be classified based on whether it is a drug-centric approach, which involves replacement of an existing drug with unwanted effects, or a disease-centric approach, which aims at improving the prognosis of rare, neglected or otherwise difficult-to-treat diseases.