As anticipated, the US Food and Drug Administration has turned down Eli Lilly's novel imaging agent Amyvid over fears that experts may not interpret the brain scans in a consistent way.
Amyvid (florbetapir) is a molecular imaging tool under investigation for the detection of beta-amyloid plaque - the presence of which is associated with Alzheimer's disease - acquired by Lilly via its purchase of Avid Radiopharmaceuticals in December 2010.
A cure for Alzheimer's has not yet been developed, and so treatment strategies are very much focused on the control of symptoms, which can make a significant difference to patients. It is thought that detection of beta amyloid plaques in the brain will help speed up diagnosis, thereby providing a means for those with the condition to get quicker access to therapy.
However, in a complete response letter to the company, the FDA said that a reader training programme must be established to ensure that scans using Amyvid are analysed accurately before it would consider issuing a marketing approval, following the advice of its Peripheral and Central Nervous System Drugs Advisory Committee, which voted (13-3) against a recommendation.
Despite the setback, Lilly says it remains confident in the data submission package for Amyvid, and that, since the need for training programme was first suggested by the FDA's advisory committee in January, it has been working on the issue and continues to do so "in an open dialogue" with the regulator.