Alzheimer's lecture highlights advances in imaging

By Jeff Carlton

Until recently, clinical trials testing the benefits of clearing out a protein that accumulates in the brains of patients with Alzheimer’s disease shared similar outcomes: failure.

The trials were successful in reducing or eliminating this protein – beta-amyloid – from the brain, but not in reducing the symptoms of dementia associated with Alzheimer’s.

“If we are right that a buildup of amyloid causes Alzheimer’s disease, then why were all these trials failing?” asked Dr. Michael Devous, Professor of Radiology at UT Southwestern Medical Center and the featured speaker at the Spring Public Forum, presented by the Friends of the Alzheimer’s Disease Center. “Because by the time people qualified for treatment, by the time they already had the clinical diagnosis of Alzheimer’s disease, it was too late. The damage had been done.”

That insight, combined with imaging advances that allow experts to measure levels of amyloid in the brain, has changed how researchers conduct clinical trials for Alzheimer’s. The research focus has shifted – from testing on those with dementia, now recognized as a late stage of the disease, to people who have detectable amyloid but no apparent symptoms of Alzheimer’s.

Dr. Devous, who directs neuroimaging at the Alzheimer’s Disease Center, will talk more about the reasons behind these clinical trial changes during his lecture, titled “Seeing Amyloid in the Living Brain – How This Impacts New Alzheimer’s Disease Treatment Trials.” The event takes place at  7 p.m. April 10 at the Simmons Biomedical Research Building.

Since the presence of amyloid in the brain can precede any symptoms of Alzheimer’s disease or dementia by up to 15 years, researchers hope that early intervention can halt or slow its buildup.

“It’s a huge change in the design of treatment trials,” Dr. Devous said.

One of the biggest advances came a year ago, when the Food and Drug Administration approved the first amyloid imaging agent, called Amyvid, for use in positron emission tomography (PET) scans. Amyvid is a radiopharmaceutical that binds to amyloid plaque and “lights up” on a PET scan, allowing radiologists to identify the presence of the harmful protein. It’s being used both clinically and in research projects.