The Wall Street Journal announced today that the Food and Drug Administration (FDA) has approved a much-anticipated Alzheimer's testing tool from Eli Lilly.
Doctors associate Alzheimer's Disease (AD), the most common form of dementia, with the presence of amyloid protein plaques. Eli Lilly's new product, called Amyvid, tags the plaques so physicians can see them in PET scans. Before, they could only see the plaques in autopsies.
The new tool would allow doctors to see these signs of AD early on in their patients, allowing for earlier treatment of the disease.
The problem, straight from the drug’s label: “A positive Amyvid scan does not establish a diagnosis of AD or other cognitive disorder.
In a 59-patient study in which a patient’s Alzheimer’s status was later determined by autopsy, all Amyvid readers got at least 5% and up to 14% of diagnoses wrong.”
The scan can rule out the disease. No amyloid plaques means no AD. But, if a person's PET scan is positive for amyloid plaques, this doesn't allow their doctor to decisively diagnose them with AD.
For this reason Herper doubts Amyvid will make much of a dent in the pharmaceutical market.
The tool will debut in limited quantities this June.
Photo: Liz West/Flickr