An Update On Florbetapir

In late January, an FDA panel assembled to review the case for Eli Lilly’s Amyvid (florbetapir) for use as a radiotracer to detect β-amyloid in the brain. While originally rejected 13 to 3, the committee later voted 16 to 0 in favor of florbetapir, if Eli Lilly can set up education initiatives to improve the consistency of those reading the imaging results. The committee stated that they would first like evidence that readers can consistently detect clear positive or negative findings.

As previously reported, florbetapir consists of a ligand labeled with the radioactive isotope fluorine-18, which targets aggregated forms of β-amyloid. The article published in January on the product found that PET studies using florbetapir correlated significantly with the severity of β-amyloid pathology at autopsy.

However, it is important to keep in mind that the company doesn’t intend to use florbetapir to diagnose Alzheimer’s. For the time being, the relevance of β-amyloid aggregates in Alzheimer’s remains somewhat elusive, especially considering the same aggregates are often found in cognitively normal elderly people as well. Instead, the goal is to use florbetpir to rule out the presence of pathologically significant levels of β-amyloid in the brain and therefore help rule out a diagnosis of Alzheimer’s.