Eli Lilly developed the test that is meant to find certain proteins in the brain that are related to Alzheimer's and other sources of dementia by using a radioactive dye, called Amyvid.
The dye adheres to an accumulation of toxic protein called beta amyloid found in the brains of patients with Alzheimer's. By using a PET scan (positron emission tomography) doctors can see where the protein has settled.
The FDA did not approve the dye in 2011 when it was first presented by Lilly, according to news reports at the time. At issue then was a large concern that medical professionals would be unable to correctly and consistently diagnose the plaque.
Lilly went back to the drawing board and developed a training program that passed muster this time around. According to the Wall Street Journal, the company worked with both the FDA and experts in the field. The result was a three-hour online and in-person training programs for physicians.
Eli Lilly does not claim that the test is meant to find Alzheimer's. Rather the company says it is intended to rule out Alzheimer's because the presence of amyloid in the brain doesn't alone suggest that someone has Alzheimer's.
One in five patients who are diagnosed with Alzheimer's turn out not to have the disease after an autopsy. Previous to the development of Amyvid and the scan, the presence of the brain plaque could only be determined in an autopsy after a person died.
"The approval of Amyvid offers physicians a tool that, in conjunction with other diagnostic evaluations, can provide information to help physicians evaluate their patients," Dr. Daniel Skovronsky, CEO of Avid said in the company's statement from Friday. Lilly's Avid Radiopharmaceuticals Inc, business unit will be responsible for selling Amyvid.
Previous to the development of Amyvid and the scan, the presence of the brain plaque could only be determined in an autopsy after a person died.
Researchers may be able to build on the success of the scan in the quest to help find early signs of Alzheimer's, ultimately leading to treatment for the disease. It has been said that drug trials to attack Alzheimer's have failed because the stage of dementia exhibited by patients in the study.
Image: Wikimedia Commons --- Alzheimer's PET scan