Controversial Alzheimer’s Testing Method

Alzheimer dementia has brain protein fragments detectable with a new dye

(RxWiki News) Alzheimer’s disease accounts for 60% to 80% of dementia cases, yet one in five cases are diagnosed as something else. Excluding Alzheimer's and looking for something else may be valuable to the patient.

The FDA approved Amyvid, a radioactive dye that will help doctors diagnose Alzheimer’s disease in brain scans. A negative study excludes Alzheimer's.  

Other conditions can give a positive scan and so a positive scan is not conclusive.

"Ask your doctor about Alzheimer’s symptoms and detection methods."

Amyvid is a dye that connects to the toxic protein deposits in the brain that are present in Alzheimer’s. With the dye the proteins are visible on a positron emission tomography (PET) scan.

The test's problem is that the protein deposits or ‘plaque’ do not always mean that the patient has Alzheimer’s, but a total lack of plaque would mean that Alzheimer’s could be excluded.

The FDA did not approve Amyvid last spring due to a fear that doctors would over diagnose Alzheimer’s since the dye only indicates that there may be a chance that Alzheimer’s is the cause for symptoms.

False positive diagnoses of Alzheimer’s are possible, but Eli Lilly is working to train doctors to read the scans as accurately as possible. The FDA appears to be giving Amyvid’s developers some leeway with this recent approval because of the  large number of Alzheimer cases and Eli Lilly's claim to train doctors to accurately read the scan through a 'reader training program' online.  

Amyvid is a radioactive dye and does add to the patient's lifetime exposure to radiation.  

Avid Radiopharmaceuticals Inc., the developer of Amyvid and owned by Eli Lilly, is facing some stiff competition for the market share of Alzheimer’s imaging agents. With fellow giants like Bayer AG, Pfizer Inc., and General Electric Co. also competing for a share of the multi billion dollar market—the first one to market has an advantage.  

CEO of Avid, Dr. Daniel Skovronsky M.D., Ph.D., hoped that Amyvid will help the medical world more accurately diagnose and equip doctors to begin early treatment for Alzheimer's disease. 

Amyvid will cost around $1,600 per dose.  This price tag does not including the price of the PET scan, which can run anywhere between $3,000-$6,000.

Funding for research and development for Avid Radiopharmaceuticals Inc. is provided by Eli Lilly Co., no conflicts of interest were found.

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Review Date: 
April 7, 2012