NEW YORK — In a significant effort to discover a treatment to prevent Alzheimer’s disease, the federal government on Wednesday announced a $33.2 million grant for a project that will test a drug on people considered at greatest risk for developing the most common form of the disease.
The grant, part of the government’s national Alzheimer’s plan, will help finance a large clinical trial to test a treatment on people 60 to 75 years old who do not have any symptoms of the disease but do have two copies of a gene known to greatly increase the risk of getting it.
It is the largest federal grant to date to test a drug designed to prevent Alzheimer’s in people without symptoms, said Laurie Ryan, program director for Alzheimer’s disease clinical trials at the National Institute on Aging, part of the National Institutes of Health.
In announcing the grant Wednesday, Dr. Richard J. Hodes, director of the National Institute on Aging, said the government was “investing a great deal of hope” in prevention research, aiming to “intervene early in the course of Alzheimer’s disease, well before the onset of symptoms.”
“We know that Alzheimer’s-related brain changes take place years, even decades, before symptoms appear,” Hodes said. “That really may be the optimal window for drugs that delay progression or prevent the disease altogether.”
The $33.2 million grant for the drug-testing project went to Dr. Eric M. Reiman and Dr. Pierre N. Tariot of the Banner Alzheimer’s Institute in Phoenix. The Banner trial will focus on the late-onset form of Alzheimer’s, by far the most common form of the disease, affecting the vast majority of the 5 million Americans estimated to have it.
Although the cause of Alzheimer’s is unknown, researchers have been able to establish certain risk factors. People with the most significant known risk so far, Reiman said, possess two copies of a gene called ApoE4, having inherited it from both parents.
Studies have found that more than half of the people with two copies of the gene will develop Alzheimer’s, compared with about one-fourth of people with one copy and 10 percent of people with no copies.
People with two ApoE4 genes make up only about 3 percent of the population, but because they develop the conventional late-onset form of Alzheimer’s, they are an important group to study. About 25 percent of the population possess one copy of the gene.
The Alzheimer’s Prevention Initiative will test a drug or placebo on 650 adults with two copies of the gene who have shown no symptoms of cognitive decline, Reiman said.
The researchers haven’t chosen the drug to be tested, but it will be a treatment that attacks amyloid, a protein that accumulates in plaques in the brains of people with Alzheimer’s.
Expected to begin in 2015, the project will ultimately cost more than $100 million, most of which is expected to be financed by the pharmaceutical industry, with some money from nonprofit sources, Reiman said.
Drug-testing will involve people in several locations, most in the United States.