Highs and lows of drug repurposing

Listen to this article on the DDW Podcast: DDW Editor Reece Armstrong explores the rise of drug repurposing and the benefits and disadvantages it brings to drug discovery and development. Drug repurposing, the act of finding new clinical targets for both approved and unapproved drugs, has emerged as a viable alternative to traditional drug discovery approaches. It’s common knowledge that drug discovery and development is costly, lengthy and has no guarantee of success. It’s why pharmaceutical companies will often spend up to 10 years and upwards of $1 billion before receiving regulatory approval for a drug. It’s also why pharmaceutical companies will look to acquire smaller biotechs and drug discovery companies, because a lot of the legwork into finding a suitable molecule for a disease has already been done. According to MarketWatch, the drug repurposing sector was thought to be worth $25,280 in 2021 and is expected to grow to $30,620 million by 2028 with a CAGR of 2.8%. This level of growth is unsurprising for an industry which will always look to the latest opportunities to drive science. Benefits and barriers Perhaps the biggest benefit drug repurposing brings is its potential to get treatments to patients faster than traditional means of drug discovery. A report by the medical charity LifeArc1 puts the timeframe for a therapy brought to market through repurposing methods at anywhere from one to three years. This is a stark contrast to the often decade-long projects that pharmaceutical companies undertake to bring a drug to market. Other benefits that come with this approach include an already established safety profile for the selected drug and readily available product and manufacturing supply chains. Indeed, having a safety profile already established could entice patients to enter clinical trials more readily than with ‘unknown’ compounds. However, challenges remain. Developers may have to establish further preclinical data for safety and exposure for the new mechanism of action, as well as identifying an optimal dosage and formulation for patients. Pharmaceutical companies will also need to assess the patent-life of the drug they’re targeting and whether they’ll face any intellectual property (IP) barriers. More so, if a drug is off-patent, the commercial viability of it can be reduced due to it no longer having exclusivity. Panna Sharma is the President and CEO of Lantern Pharma, a company utilising artificial intelligence (AI), machine learning and genomics to advance the timeline of drug discovery and development. To date, the company’s nine programmes have “been guided through the use of AI and machine learning approaches.” The company’s utilisation of AI means that Lantern Pharma has an increased ability to both “rescue failed therapies and compounds and develop entirely new drug candidates,” says Sharma. On the importance of technology like AI and machine learning for repurposing drugs, Sharma says: “By using advanced data, computational modelling tools and AI platforms, companies can be constantly searching for ways to exploit new disease insights with existing approved therapies and potentially failed or shelved compounds. Typically this has been a very niche category within biopharma with some brilliant minds using manual techniques, extensive laboratory work and little data sharing - but with the advent of large scale biomarker studies, improved compound modelling and availability of real-world data, we can develop highly parallel systems that are doing this all day. This work can be directed at specific disease categories or mechanisms, and change our cost structure and success rates in repurposing drugs and compounds.” Compared to traditional drug discovery approaches, companies that can understand, model and leverage historical data could potentially save “tens of millions of dollars and many years (two to four) by repurposing a drug and heading directly into Phase II with a compound that has both historical safety and dosing data along with clear chemistry, manufacturing and controls (CMC) requirements,” Sharma says. “There is also an added benefit of potentially understanding the mechanism of action and designing a trial that can find and monitor this biological feature through biomarkers or genomics in patients. This of course has many assumptions behind the repurposing such as indication(s), use of combination agents, dosing and potential clinical benefits,” he adds. Blair Jackson is the Executive Vice President and Chief Operating Officer at Alkermes, a biopharmaceutical company that uses the approach of molecule re-engineering to address unmet needs of people living with complicated and difficult-to-treat disease. In terms of the benefits drug repurposing can bring, Jackson says that if “done right, a drug developer has an opportunity to reduce overall drug development risk through some of these repurposing strategies.” “In addition to reducing risk inherent in drug development, leveraging previous research experience could save time and money due to information lessons previously learned about the dosing, pharmacokinetics and safety profile of the original drug, potentially making an effective treatment option available sooner to the patients who need it,” he adds. Diving into data Improvements in technology and changes to worldwide regulations in life sciences has led to an increase in the availability of clinical data. Remote trials, wearable devices and advancements in genomic sequencing means that clinical data is now more abundant than ever and is only set to grow. Earlier this year, the European Commission’s Clinical Trial Regulation (EU No 536/2014) came into effect, bringing with it the stipulation that pharmaceutical sponsors and investigators must archive data from a clinical trial master file, 25 years after the particular trial has ended. This type of digital archiving intends to make data readily available and easily accessible for companies pursuing pharmaceutical research and development. In Europe, there is a similar approach being taken by the European Medicines Agency (EMA) through a pilot project designed to support repurposed medicines. The project is inviting not-for-profit organisations and academia to generate evidence on established medicines for a new indication. The idea is that this evidence will be used by regulatory organisations as part of a data package that can support pharmaceutical companies when they submit an application for a drug targeting a new indication. Global efforts As it stands, drug repurposing has become a targeted effort by institutions all across the world. For instance, the NHS launched its Medicines Repurposing Programme in 2021 in a bid to establish new opportunities to repurpose prioritised medicines, with a focus on improving evidence bases for off-label drugs and to incentivise generics companies to support licensing efforts so that repurposed medicines applications don’t face as many regulatory barriers. In the US, the Drug Repurposing Hub was launched in 2017 to fill a gap in large-scale, systemic approaches to the practice of repurposing therapeutics. To do this, the Drug Repurposing Hub has developed an open-access library of over 6,000 compounds, which are being tested against disease models in an effort to find new treatments using small molecules – many of which have already been approved by the FDA. Volume 23 – Issue 4, Fall 2022 References https://www.lifearc.org/wp-content/uploads/2021/06/LifeArc-Repurposing-digital_FINAL.pdf