An international team of researchers, led by a scientist from Boston’s Brigham and Women’s Hospital, has convinced federal regulators to relax rules that had barred many Alzheimer’s patients from clinical trials of a medication designed to halt the disease.
The team found that brain swelling and tiny tears in brain blood vessels, identified in many of the study patients, typically did not cause them pain or other complications, according to the researchers’ study presented today in Paris at the Alzherimer’s Association International Conference.
The patients had been given various doses of bapineuzumab, a protein that researchers believe will help clear their brains of sticky amyloid plaques, the substance scientists believe is responsible for killing brain cells in Alzheimer’s patients. The aim is to slow or halt the progression of the disease.
The U.S. Food and Drug Administration last year issued rules that required researchers to remove patients from these trials if they developed any brain vessel tears during a study. The rules also excluded any patients from enrolling in the studies if a scan revealed more than two of these tears.
But the agency recently relaxed those guidelines after a team of scientists reviewed tests on a sampling of the patients and found few problems.
“We don’t want to make everyone who develops these abnormalities to drop out of trials because they are the very people who may be helped,” said Dr. Reisa Sperling, an associate professor of neurology, Harvard Medical School and the Brigham researcher who led the study.
The researchers reviewed more than 2,000 brain imaging tests from patients enrolled in the trials and found that approximately 40 percent had swelling or mico-brain bleeds while taking the study medication but apparently experienced few serious side effects.
Sperling said the review found that the tiny brain bleeds were in the same area that the medication appeared to clear the amyloid plaques.
“That’s evidence we may be hitting our target,” she said.
Dr. Sanford Auerbach, an associate professor of neurology and psychiatry at the Boston University School of Medicinewho was not involved in the review, said the team’s work will mean more Alzheimer’s patients will be able to enroll in the bapineuzumab studies.
While the brain swelling and tears are concerning he said, “I don’t believe more patients
would be put at risk by liberalizing these rules.”
Alzheimer’s is the sixth leading cause of death in the U.S. but scientists have yet to find a way to prevent, cure or even slow its progress.
Another study presented today at the Paris conference found that more than 2,000 people surveyed in four countries -- the U.S., France, Germany and Spain -- Alzheimer’s was the disease that people were second most afraid of getting, behind cancer. In a fifth country, Poland, Alzheimer’s was third behind cancer and heart disease.