Regulators, researchers and drug companies must work quickly to develop faster and less expensive trials for treatments to prevent and treat Alzheimer’s disease, scientists said on Sunday.

Promising medications are in the works, but human trials are time-consuming and costly, and an avalanche of Alzheimer’s cases is expected as the baby boom generation ages, they told a conference.

“We need to reduce the time it takes to do these studies, cut the costs involved, and find ways to conduct effective studies with fewer numbers of participants,” said Dr. Marcelle Morrison-Bogorad, an associate director at the National Institute on Aging.

The disease, which helped kill former U.S. President Ronald Reagan last month, affects some 4.5 million Americans and touches one in 10 U.S. families.

The number of cases in the United States has doubled since 1980 and is expected to nearly quadruple to 16 million by 2050.

Symptoms of Alzheimer’s start out with memory loss, difficulty performing familiar tasks, problems with language and loss of initiative. Patients eventually become totally dependent on caregivers.

Medicare costs of the disease are projected to rise 55 percent to $49.3 billion by 2010. The average lifetime cost of care for someone with Alzheimer’s is $170,000, the Alzheimer’s Association said.

GINKGO, NSAIDS

One current trial focusing on the ginkgo biloba leaf involves more than 3,000 participants aged 75 and older for at least six years at a cost of more than $24 million.

Another is looking at whether two non-steroidal anti-inflammatory drugs, or NSAIDs, can help prevent Alzheimer’s in healthy people. It has so far enrolled about 2,500 of an intended 4,000 participants at a cost of some $25 million.

The use of NSAIDs, a drug category that includes aspirin and ibuprofen as well as COX-2 inhibitors, has potential, said Dr. John Breitner of the University of Washington, who leads a trial of the drugs naproxen and Pfizer’s Celebrex, known generically as celecoxib.

“The preliminary data that NSAIDs can prevent Alzheimer’s is very encouraging, but the treatments have known side effects and there are real difficulties with administration of these or other biologically active compounds to seniors in trials over several years,” Breitner told reporters.

A project led by Dr. Steven Ferris of the New York University School of Medicine is trying to develop more efficient methods such as home-based testing, using fewer participants.

“We’re trying to find out if we can reduce the need for the participants to come in to the clinic,” Ferris said. “We can save considerable time and expense if the participants don’t have to come in so often.”

Meanwhile, researchers reported mixed results from tests on whether the cholesterol-lowering statin drugs can also help prevent Alzheimer’s.

Scientists at the University of Alabama at Birmingham found that aging mice treated with simvastatin - marketed by Merck and Co. as Zocor - regained their ability to navigate mazes after being injected with the drug.

But another trial at Duke University involving 30,000 people without dementia has found no evidence yet that any statin protects against cognitive decline.

Small trials of the popular Alzheimer’s drug Aricept show mixed results on whether it can prevent the disease. The latest study presented at the Philadelphia conference suggests its use can delay the worst symptoms by about 18 months.