Dr Arun Kumar Pandey, Senior Vice President, Research and Development, Alkem Laboratories, explains the various advantages, challenges and opportunities associated with drug repurposing
Drug repurposing with Dostarlimab shows promising results in treating colon cancer. In the current global scenario, pharma industry faces the challenge of slow conversion of knowledge to treat human diseases into medicinal benefits despite the amelioration of technology. The development of new drug is a strenuous process, influenced by the high monetary value and time requirement. A timeline of 10-15 years, along with infusion of funds ranging from $500 million to $2 billion is what the process of the current drug development requires. In order to subdue these challenges, a strategy of drug repurposing has been widely adopted by various pharma firms. In these coming years, repurposed drugs awaiting approval from regulatory authorities could rise and account for about 20-30 per cent of all the drugs approved every year, according to different estimations.
Drug repurposing could be easily understood as an approach for figuring out new therapeutic uses of an accepted drug that vary from the original medicinal effects for which the medical indication initially was used. It is also known as drug reprofiling or drug repositioning. The drug molecules that have been dropped due to certain reasons during the trial phase or the development phase can also be repurposed.
The advent of drug repositioning started with Aspirin (acetylsalicylic acid) in 1980s. Currently used as an anti-platelet aggregation drug at lower doses, Aspirin was marketed as an analgesic in 1899 by Bayer prior to its repositioning. Some of the notable examples of repurposed drugs include Sildenafil, Celecoxib. Sildenafil was repurposed by Pfizer.
Originally developed as an anti-hypertensive, Sildenafil was repurposed and was finally marketed as Viagra used in the treatment of erectile dysfunction, while 53 per cent market share was held by other marketed drugs during the drug market in 2012. The rest was held by Viagra with the sales up to $2.05 billion. Celecoxib’s original indication was for pain and inflammation, but was repurposed for familial adenomatous polyps using pharmacological analysis as the repurposing approach. It was repurposed by Pfizer at the latter half of 2014.
The piqued interest in the area of drug repurposing is due to the high failure rate and extensive financial issues faced by the company when adopting the conventional method of drug development. The driving force behind the success of drug repurposing technique is the availability of pre-existing data on safety and toxicity trials. The scientific landscape for research and drug development is still undergoing changes, but the process is expected to pick up pace in the upcoming years.