Could drugs that manage heart disease be used to treat dementia?
Dr Terry Quinn is leading an innovative project within the Vascular Health theme of DPUK's Experimental Medicine Incubator. Based at the University of Glasgow, Dr Quinn is searching for medications used to treat heart disease that may have the side-effect of treating dementia.
DPUK: Why do you think these drugs will have positive effects on the brain?
TQ: There is a long history of drugs being developed for one purpose ending up being used to treat something completely different. Most people have heard of Viagra, which was initially taken to reduce blood pressure before men started reporting a very specific side effect… Prozac also started life as a cardiovascular drug and is now one of the leading antidepressants on the market.
Because the cardiovascular system – that is, the network of blood vessels in the body – flows through the whole body and a disproportionately large amount of blood is directed to the brain, there are biological reasons to think drugs that improve blood flow could also improve brain health.
How are you investigating this?
There are several stages to this project, the first of which involves scouring huge datasets from UK Biobank. These datasets include over half a million people taking various heart medications, who also had their brains scanned and thinking skills measured. We are trying to find any medications for heart disease that are associated with healthier brain scans or better scores on memory assessments.
Once we have identified a list of drugs that could offer potential cognitive benefits, we will investigate these using richer data in the DPUK Data Portal. At the end of this analysis, we hope to have identified two or three medications to take to a clinical trial where they will be tested in people living with dementia or at risk of dementia.
In this final stage, we will work closely with a clinical trials team within DPUK to conduct a large, randomised trial to find out whether the drugs realise the benefits our research predicts they will.
This is a great example of how the whole DPUK community can work together towards a common goal. Even before we started analysing the data, we will use the DPUK network to bring together experts to discuss which heart medications are most likely to show benefits in the brain.
Why is this work so important?
We are playing a crucial role in raising the profile of research in the vascular space, along with groups like VasCog, VISTA and Opsyris, with whom we collaborate closely. Despite vascular dementia being more common than other types of dementia, it lacks the same visibility.
Improving the visibility of research into vascular dementia will create increased awareness of the condition and what people can do to reduce their likelihood of developing it.
Why is repurposing existing drugs a good strategy?
By using drugs that we already know are safe and effective in humans, we can side-step a lot of the stages of drug development. This not only speeds up the process, but also cuts a lot of the costs involved.
When researchers talk about a quick turnaround, it may not be quite what people have in mind. From the initial stage of gathering expert knowledge to the clinical trials going ahead will take around two years. But the process of developing a new drug from scratch usually takes around 20-25 years. So, when you put what we're doing in context, it really is very quick.
Why hasn't this been done before?
Although there have been other examples of repurposing drugs, these were largely down to chance observations. Now, we have the analytical capabilities through advanced computer technology to conduct this large data-driven research. The scale of what we're doing is enormous – we have half a million participants, all taking up to seven different medications and then we have to analyse several memory and thinking tests and differing brain scan assessments.
In general, I also think there is still silo-thinking in the research world. For example, people see stroke and dementia as separate diseases, and mental health as distinct from physiology. We need to break down the silos and not define brain health and vascular health as separate fields. Doing this will pave the way for future innovations to help treat diseases like dementia.
Dr Quinn's project is a DPUK Work Package within the Experimental Medicine Incubator – keep an eye on DPUK's news section for updates as it progresses. You can also read our blog post exploring the link between brain and heart health for more information about how the two are related.