The Alzheimer's Drug Discovery Foundation (ADDF), based in New York, and the Alzheimer's Society U.K. have announced new funding to explore the possibility of using a commonly prescribed drug which treats erectile dysfunction as the next treatment for dementia. Tadalafil—part of the same class of drugs as Viagra—is to be one of the major research programs funded by the two charities in a cross-Atlantic research partnership. This is the first ever study researching the use of an erectile dysfunction drug for vascular dementia.

Nearly $500,000 will go to a team of scientists led by Dr. Atticus Hainsworth of St. George's University of London to research 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 more than one million cases of dementia in the U.S. The condition often is 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—commonly is seen in the brains of elderly people. In fact, 50% to 70% of older people, especially those over 80, have "mixed dementia," a combination of vascular brain disease and Alzheimer's. 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, another $250,000 investment will go to Professor Christian Holscher of Lancaster University to investigate whether experimental diabetes drugs could help reverse the onset of Alzheimer's disease. The study 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 now will begin work to look at whether two new, more potent diabetes drug candidates have the same or more significant effects on Alzheimer's.

The ADDF and the Alzheimer's Society also are currently co-funding a clinical trial of liraglutide at the Imperial College London in patients with early Alzheimer's disease.

The ADDF and the Alzheimer's Society U.K. have both made significant recent investments in repurposing, which takes FDA-approved drugs that already are being used to treat other conditions and tests their potential to in diseases like Alzheimer's. This innovative approach can rapidly accelerate the drug discovery process, bringing new treatments to patients in half the time required for a drug that hasn't already earned FDA-approval.

"Drug development can take decades and sadly, the path toward 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," said Dr. Doug Brown, director of R&D at Alzheimer's Society. "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."