Amyvid
Medicare Officials Want More Amyvid Trials
Eli Lilly & Co. says it will push ahead with an imaging chemical designed to help screen for Alzheimer’s disease, despite a negative ruling by Medicare officials. The Centers for Medicare and Medicaid Services said last week it will not cover the chemical which highlights brain plaque in medical imaging scans.
Eli Lilly & Co. says it will push ahead with a first-of-a-kind imaging chemical designed to help screen for Alzheimer’s disease, despite a negative ruling by Medicare officials.
The Centers for Medicare and Medicaid Services said last week it will not cover the chemical, called Amyvid, which highlights brain plaque in medical imaging scans. The government program provides health coverage to more than 47 million seniors, and is the largest payer for prescription drugs in the U.S.
Amyvid contains florbetapir F 18, a molecular imaging agent that binds to β-amyloid aggregates, and is intended for use with PET imaging of the brain. Chemically, florbetapir F 18 is described as (E)-4-(2-(6-(2-(2-(2[18F] fluoroethoxy)ethoxy)ethoxy)pyridine3-yl)vinyl)-N-methylbenzamine. The molecular weight is 359 and the structural formula is:
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Amyvid is a sterile, non-pyrogenic radioactive diagnostic agent for intravenous injection. The clear, colorless solution is supplied ready to use and each milliliter contains 0.1 to 19 micrograms of florbetapir and 500 – 1900 MBq (13.5 – 51 mCi) florbetapir F 18 at EOS, with 4.5 mg sodium ascorbate USP, and 0.1 mL dehydrated alcohol USP in 0.9% sodium chloride injection USP. The pH of the solution is between 5.5 and 7.5.
Physical Characteristics
Amyvid is radiolabeled with [18F] fluorine (F 18) that decays by positron (β+) emission to O 18 and has a half-life of 109.77 minutes. The principal photons useful for diagnostic imaging are the coincident pair of 511 keV gamma photons, resulting from the interaction of the emitted positron with an electron (Table 3).
Table 3: Principal Radiation Produced from Decay of Fluorine 18
| Radiation | Energy Level (keV) | Abundance (%) |
| Positron | 249.8 | 96.9 |
| Gamma | 511 | 193.5 |
