A commonly prescribed drug used to treat men with erectile problems could become the next treatment for dementia, according to Alzheimer's Society and Alzheimer's Drug Discovery Foundation (ADDF).
Tadalafil – part of the same class of drugs as Viagra – is to be one of the drugs investigated in new research funded by the two charities in a cross-Atlantic research partnership.
The announcement today (Thursday 11 December) comes on the one year anniversary of the first G8 summit on dementia. The event saw global leaders call for increased investment and global collaboration in dementia research in order to find a disease-modifying treatment by 2025.
Scientists led by Dr Atticus Hainsworth at St George's, University of London will explore whether tadalafil, which works by dilating blood vessels, could help prevent vascular dementia by increasing blood flow to the brain.
Vascular dementia is the second most common form of dementia and accounts for around 110,000 cases of dementia in the UK. The condition is often caused by damage to the small blood vessels of the brain leading to reduced blood flow to brain tissue. This blood vessel damage – known as small vessel disease – is seen in the brains of 50-70 per cent of older people. The researchers hope that tadalafil's blood-flow boosting properties can prevent the damage that leads to vascular dementia.
In addition to this clinical study, the charity partnership will also fund research exploring whether an experimental diabetes drug could help reverse the onset of Alzheimer's disease. The study, led by Lancaster University's Professor Christian Holscher, follows up on the academic's previous work showing that the diabetes drug liraglutide could reverse memory loss and the build-up of plaques in the brain characteristic of Alzheimer's. Professor Holscher will now begin work to look at whether two new, more potent diabetes drugs have the same or more significant effect on Alzheimer's.
These grants form part of Alzheimer's Society's flagship Drug Discovery programme. It focuses on drug repurposing, which takes drugs that are already being used to treat other conditions and tests their potential as a treatment for dementia. This innovative approach means that new, better treatments could be available in half the time of a new drug, bringing hope to people with dementia and their carers.
Dr Doug Brown, Director of Research and Development at Alzheimer's Society, said:
'Drug development can take decades and sadly, the path towards developing dementia treatments over the past decade is littered with drugs that have failed in clinical trials. As we learn more about the causes of dementia and its links to other conditions, there is hope that treatments we routinely use for other diseases may also work for people with dementia.
'These incredibly exciting studies could see existing treatments turned into drugs for the most common forms of dementia in a fraction of the time and at a fraction of the cost of developing new drugs from scratch. By next year 850,000 people in the UK will have dementia and we owe it to them to do everything we can to develop better treatments and ultimately find a cure. Research like this is a huge part of that goal.'
Howard Fillit, MD, Chief Scientific Officer at ADDF said:
'We're thrilled to partner with Alzheimer's Society on this important effort to reposition and repurpose drugs developed for other diseases for Alzheimer's patients. Working with the charity has enabled us to leverage our respective funding and research networks to support these innovative programs.'
Dr Atticus Hainsworth, lead researcher on the tadalafil study at St George's, University of London, said:
'My colleagues and I are very enthusiastic about this trans-Atlantic initiative as there are too few drugs in the medicine cupboard for dementia. We want to know whether a well-known, well-tolerated drug can be used to combat dementia, which has been called the twenty first century plague.
'The drug tadalafil is widely used to increase blood flow in penile tissue. Now we're asking whether it can do the same for another vital organ - the brain.'