The US Food and Drug Administration (FDA) has approved the GE Healthcare diagnostic imaging tracer flutemetamol F18 (Vizamyl) for use in evaluating adults for Alzheimer's disease and dementia.
Vizamyl is the second radioactive diagnostic tracer approved by the FDA for illuminating amyloid plaque development in the brain in PET studies. The first was Eli Lilly and Company’s, florbetapir F18 injection (Amyvid).
Amyvid is a costly tracer that is only reimbursed by Medicare in very limited "coverage with evidence" research situations. As such, the Amyvid test is rarely provided outside of academic settings.
However, if Alzheimer’s testing becomes more broadly covered by Medicare in the future (a possible scenario if a successful treatment is developed), then Alzheimer’s testing could be a $20 billion market, according to Bloomberg News.
Being among the first tracers approved may be one key to tapping this market because it takes time for radiologists to become adept at reading PET/CT beta-amyloid imaging studies. All else being equal, the tracer that has the most radiologists trained to read it would have an advantage.
Outside of academic circles, RadNet’s “Shine a Light on Dementia” program has the largest number of outpatient imaging centers providing testing with the Amyvid tracer, and it created an internal program to allow its subspecialists reading these studies to learn from each other.
In July, RadNet also partnered with Eisai Co., Ltd., on a Phase 1 trial of E2609, a BACE (beta-site amyloid precursor protein-cleaving enzyme) inhibitor, in part because the trial was using the the then not-yet-FDA-approved Vizamyl as the tracer. That meant that RadNet radiologists would get experience reading tests using both Amyvid and Vizamyl.
“It is a very big educational benefit," said Judith Rose, MD, director of PET/CT and nuclear medicine for RadNet, in an interview in July. "There are not a lot of people in the general community who will have experience with it and we’ll have an advantage because we will have seen quite a few cases by the time it gets clearance.”