99 percent of drugs to treat Alzheimer's fail or are discontinued

A news study has shown that 99 percent of the drug trials for Alzheimer’s patients have failed in the past decade.
The report, published in the journal Alzheimer’s Research & Therapy, says that only one new drug has been approved since 2004.
Scientists in the United States say that there is an urgent need to increase the number of therapies available to those who suffer from Alzheimer’s, according to BBC.
Scientists, according to Medical Daily, are worried that there really may be no therapies available to treat the disease. Though the Food and Drug Administration has approved drugs that treat the symptoms of Alzheimer’s, they have not approved any (except one) that can help prevent or possibly cure the disease.
The drug failure rate for Alzheimer’s is higher than the failure rate for cancer. Between 2002 and 2012, researchers found that 99.6 percent of trials of drugs to cure or prevent Alzheimer’s had either failed or been discontinued.
The failure rate for cancer drugs in 81 percent. The failure rate was "especially troubling" given the rising numbers of people with dementia, said Dr Simon Ridley, Alzheimer's Research UK.
"The authors of the study highlight a worrying decline in the number of clinical trials for Alzheimer's treatments in more recent years," he said.
Five million people suffer from Alzheimer’s worldwide. It is the most common form of dementia. By 2050 scientists think that the number of people that suffer from Alzheimer’s may rise to 16 million.