An advisory committee to the Food and Drug Administration recommended unanimously Thursday that the agency approve the first test - a brain scan - that can show the characteristic plaques of Alzheimer's disease in the brain of a living person. The approval was contingent on radiologists agreeing on what the scans say and doctors being trained in how to read the scans.
The F.D.A. usually follows advice from its advisory committees, and Alzheimer’s experts anticipated that the scans would be approved. The additional requirement would not be a big hurdle, said Dr. Daniel M. Skovronsky, chief executive of the company, Avid Radiopharmaceuticals, that applied to market the scans.
“We don’t know exactly what F.D.A. will want,” Dr. Skovronsky said. “But it should take months to generate this type of data, not years.”
The committee vote is “a very positive thing,” said Maria Carrillo, senior director of medical and scientific relations for the Alzheimer’s Association. “This is nothing but a positive for our families.”
More than five million Americans have Alzheimer’s disease.
Plaques are part of the criteria for having Alzheimer’s - if a person with memory problems does not have plaques, that person does not have Alzheimer’s. But without the scan, the only way to know if plaques were present is to do an autopsy.
Alzheimer’s specialists said they expected that if the scan were approved it would come into widespread use.
“This is a big deal,” said Dr. Pierre N. Tariot, director of the memory disorders center at the Banner Alzheimer’s Institute in Phoenix. Asked if he would be using the scans, Dr. Tariot replied, “Absolutely.”
Dr. Tariot is an investigator in studies by Avid, now a subsidiary of Eli Lilly & Company, and its competitors.
The approval would be for a dye that homes in on plaque in the brain, making it visible on PET scans. Such scans would be especially valuable in a common and troubling situation - trying to make a diagnosis when it is not clear whether a patient’s memory problems are a result of Alzheimer’s disease or something else. If a scan shows no plaque, the problems are not caused by Alzheimer’s and could be from tiny strokes or other diseases.