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Alzheimer's Disease

99.6 percent of Alzheimer’s disease drug trials fail, experts find

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Approximately 99.6 percent of Alzheimer’s disease drug trials are unsuccessful, according to new research from the Cleveland Clinic.

Using data from ClinicalTrials.gov – a government website that tracks ongoing clinical trials – researchers discovered that from 2002-2012, 244 drugs had been tested— and only one drug was a success.

With 10,000 baby boomers reaching the Alzheimer’s risk period, the need for drug treatment is immediate, the researchers said.

“We’re looking forward from 5.5 million victims [now] to around 14 million by 2050 if we don’t develop something. Yet we’re meeting this with a trickle of success in terms of drug development,” lead author Dr. Jeffrey L. Cummings, director of the Cleveland Clinic Lou Ruvo Center for Brain Health, told FoxNews.com. “The dramatic message is that Alzheimer’s disease drug development is in a disastrous state and we have to change this.”

Alzheimer’s disease is the most common form of dementia and causes memory, thinking and behavior problems. According to the Alzheimer’s Association, there is no current cure, though some symptoms are treatable.

Alzheimer’s memory problems appear to be caused by the formation of two major tissues in the brain – plaques and tangles. Plaques form when beta-amyloid proteins clump together, blocking cell-to-cell signaling. According to Cummings, plaque appears to come first in the degeneration process, but these clusters do not seem to damage the brain’s cells. Tangles are twisted strands of the protein tau. When they begin to form, nerve cells begin to die, causing memory failure, personality changes and other symptoms of the disease.

Currently, most drugs have been aimed at preventing plaque buildup, but the high failure rate of these drugs suggests the need for a better understanding of the disease itself, as well as a broader focus on other drug targets, such as the cell-killing tangles.

“I would argue that just as you would diversify an investment portfolio, you need to diversify [the drug development] portfolio to ensure there’s a chance for success,” Cummings said.

Another consideration is the economic impact of Alzheimer’s disease. According to the Alzheimer’s Association, in 2014, the estimated cost to Americans for the care of those of Alzheimer’s will be $214 billion— and an estimated $1.2 trillion in 2050.

“We are investing about $600 million per year in Alzheimer’s research and about $6 billion per year in cancer research… at the same time that Alzheimer’s is having a larger impact on the U.S. economy,” Cummings said. “That doesn’t mean we should be doing less cancer research; we should be doing more Alzheimer’s research.”

Lack of standardization among clinical trials is another roadblock to drug testing success, as inconsistent procedures can make data appear to be more or less successful, Cummings noted.

So far, five drugs have been approved for the treatment of Alzheimer’s, yet they only treat symptoms of the disease, not the underlying plaque and tangle process. One explanation for this is that scientists better understand the mechanics of Alzheimer’s symptoms, making it technically more difficult to develop drugs that modify the disease.

“Our new science is pointing us toward the plaque and tangle process; if we could arrest that process particularly early, we could keep people at a very high functional level,” Cummings said.

Additionally, Cummings pointed out that it takes 10 years for a drug to make it through the pipeline— meaning the science of drugs being tested now is already a decade behind. However, the protocol for testing procedures is unchangeable, meaning this delay is an inherent part of the drug development problem.

Developing drugs to combat Alzheimer’s disease is a multi-faceted and complex process, and these researchers hope their findings will highlight the importance of increased efforts.

“Overall, my message is we’re doing too little, investing too little; we need the help of the government, philanthropists, advocacy groups, venture capital,” Cummings said. “We need a very comprehensive approach to developing new treatments for Alzheimer’s disease, because it’s truly in a disastrous state.”