A type of drug that may offer promise in treating Alzheimer's disease works in three ways to fight the formation of "plaques" in the brain that are a hallmark of the ailment, scientists said on Wednesday.
The researchers looked at a kind of drug called a gamma-secretase modulator, or GSM, now being tested to see if it slows Alzheimer's disease progression.
One GSM drug now being tested in people with Alzheimer's is Myriad Genetics's Flurizan, also called tarenflurbil.
A series of lab experiments showed these drugs inhibit production of long pieces of amyloid beta protein in the brain, block them from forming clumps, and boost production of shorter pieces that can make the longer ones less likely to stick together, the researchers said.
"In fact, you're sort of getting three bangs for the buck," Dr. Todd Golde of the Mayo Clinic in Jacksonville, Florida, one of the researchers whose findings appear in the journal Nature, said in a telephone interview.
These abnormal clumps in the brain, called amyloid plaques, are considered a major feature of the disease, along with tangled bundles of fibers known as neurofibrillary tangles.
Results from a Flurizan study involving 1,600 people with Alzheimer's are expected this summer, Golde said.
Alzheimer's disease is incurable and is the most common form of dementia among older people. It affects the regions of the brain involving thought, memory and language.
An estimated 5.2 million people in the United States have Alzheimer's, according to the Alzheimer's Association, and 26 million globally — a number projected to grow to 106 million by 2050.
Amyloid beta protein seems to be harmful only when it sticks together and accumulates in the brain, the researchers said. This type of drug actually sticks to the amyloid beta protein, preventing it from clumping, they said.
Myriad Genetics did not fund this study but has funded other work by Golde.
A number of other companies, including Elan and Wyeth, are developing drugs that also aim to fight beta amyloid plaques, but are not GSM drugs like the Myriad Genetics's Flurizan.