Lilly gets green light for Alzheimer's imaging agent in US

Eli Lilly has won approval for its Alzheimer's disease imaging agent Amyvid (florbetapir F18) in the US at its second attempt.

The radio-diagnostic agent is indicated for brain imaging of beta-amyloid plaques in patients with cognitive impairment who are being tested to see if their symptoms are Alzheimer's-related or the result of some other cause of cognitive decline.

Lilly notes that a negative Amyvid scan indicates sparse to no amyloid plaques are currently present, which is inconsistent with a neuropathological diagnosis of Alzheimer's disease.

On the other hand, the presence of amyloid is consistent with Alzheimer's, but also other types of neurological conditions and normal aging.

The firm is therefore at pains to point out that the agent does not provide a definitive diagnosis, and should be used in conjunction with other clinical information.

That is one reason why Lilly failed to win approval for Amyvid at its first attempt, with the FDA rejecting its application last year amid concerns that the scans achieved with the imaging agent could be hard to interpret correctly and consistently without adequate technician training.

Since then, the company has been working on the development of a training programme alongside the FDA and nuclear medicine experts, and said in a statement that "Amyvid images should be interpreted only by readers who have successfully completed Amyvid reader training."

Lilly's share price dipped slightly despite the news, likely reflecting an expectation that sales of Amyvid will remain modest while reimbursement is not covered by the US's Medicare and Medicaid health insurance systems.

Analysts have suggested that without widespread reimbursement sales could be as low as $100m a year, rising to $500m or more if the Centers for Medicare and Medicaid Services change their position.

Meanwhile, competing imaging agents are also coming through development, notably GE Healthcare's flutemetamol and Bayer's florbetaben, both of which are in phase III testing.