FDA Declines Approval of Lilly's Amyloid Tracer, For Now

On Friday, Lilly announced that the FDA will require the company to establish a reader training program before it can approve the amyloid-imaging agent Amyvid (florbetapir F18 injection). (For background reading on this arguably useless radioactive PET tracer, go here, here, and here.) News of the agency's stipulation was received by way of an all-but-damning complete response letter on Friday, March 18. The response "was primarily focused on the need to establish a reader training program for market implementation that helps to ensure reader accuracy and consistency of interpretations of existing Amyvid scans," said Lilly.

As written here, Lilly is heavily invested in the once-hugely popular, but probably misguided, idea that amyloid is the chief diagnostic and therapeutic target for established Alzheimer disease. The company's singular investment in the amyloid theory—including the development of 2 amyloid-directed agents* and last year's purchase of Avid Pharmaceuticals (the original owner of Amyvid)—may have led to the abrupt departure of the company's head of neuroscience research, David S. Bredt, last month.

PET = positron emission tomography.

* The clinical development for 1 of which (semagacestat) was scrapped, and for the other (solanezumab) may be in danger.

Photograph of atrophied brain from person with AD: National Institute on Alcohol Abuse and Alcoholism.