USA TODAY - July 22, 2004
PHILADELPHIA -- An experimental Alzheimer’s vaccine appeared to hold the line on memory loss in some patients who had gotten a few injections before the trial was halted for safety reasons two years ago, a study released Wednesday says.
Those findings, together with preliminary results on another drug presented here at the ninth International Conference on Alzheimer’s Disease and Related Disorders, raise the hope that compounds designed to attack the abnormal brain deposits of Alzheimer’s might stop the relentlessly progressive brain disease.
About 4.5 million Americans have Alzheimer’s disease, a caseload that costs the nation about $100 billion a year.
’’If we could delay the disease by just five years, we’d cut the cost in half,’’ says Sam Gandy, a neurologist at the Thomas Jefferson University in Philadelphia.
Sid Gilman, a neurologist at the University of Michigan, reported Wednesday on an approach that might delay the disease -- if safety problems can be fixed. Gilman and his colleagues gave 300 patients one to three doses of the vaccine before Irish drug company Elan stopped the trial in 2002 after 18 people developed a potentially life-threatening brain inflammation.
Out of 300 people who had received the drug, 59 responded by making antibodies to beta amyloid, the protein that clumps together to form the damaging deposits. In theory, the vaccine leads the body to make antibodies that instruct cells in the brain to destroy the deposits.
The team tracked those people for a year and found that the drug seemed to slow their memory loss compared with the control group. In addition, autopsies of four people who died for other reasons during the study showed that the vaccine appeared to remove brain deposits.
A second report suggests that people who responded to the vaccine had more brain shrinkage. But Gilman says the shrinkage occurs as a byproduct of the brain clearing out the deposits.
Elan is now working with Wyeth on another approach in which researchers will give patients injections of the antibody itself. But that trial just started, and it could be years before the results come in.
Also at the meeting, sponsored by the Alzheimer’s Association, Paul Aisen at the Georgetown University Medical Center in Washington, D.C., reported on a study of 58 patients taking an experimental drug called Alzhemed. Alzhemed stops beta amyloid from clumping, possibly preventing the deposits from forming.
After three months, Aisen and his colleagues found the drug appeared safe, with just a few reports of nausea and vomiting. An analysis of 10 people with mild Alzheimer’s suggested that the drug had slowed their decline.
’’That’s pretty encouraging,’’ Aisen says. ’’But it’s not proof.’’ To get that proof, the company is launching a large, nationwide study of Alzhemed.
Drugs like these won’t reach patients for at least five years -- assuming there are no more pitfalls in the testing process.
’’We’ll know a lot more about both of these drugs a year from now,’’ Gandy says.