Late on Friday, Eli Lilly put out the word that the FDA had approved its brain dye--Amyvid--for use in ruling out Alzheimer's. But Lilly ($LLY) will have to do much more work before it can ever expect to win the right to use the test to conclusively diagnose the epidemic ailment.
A PET scan is used to light up the presence of beta amyloid in the brain after the dye is injected, highlighting a toxic protein that appears to have a highly complex relationship with the disease. Because beta amyloid accumulates naturally, the agency has not allowed the test to be used solely to diagnose the disease. But if beta amyloid accumulations are present along with significant symptoms of the disease, such as cognitive decline, the test can help guide a diagnosis.
If that rather convoluted explanation doesn't sound clear, you'll have a better understanding of the challenges physicians face in diagnosing the disease these days.
The thorny issues surrounding a diagnosis led an expert committee as well as the agency to reject Lilly's Amyvid early last year. The outside experts were particularly worried that physicians wouldn't understand just how to use it, potentially triggering a flurry of false diagnoses. Then in early 2011 Lilly CEO John Lechleiter--who agreed to pay up to $800 million when Lilly acquired Avid Radiopharmaceuticals--predicted that an approval was only months away as the company worked out the details of a training program that could help avoid incorrect diagnoses.
At this point, Amyvid is being given a tentative nod as a new tool in the fight against Alzheimer's. And Avid is being careful not to overpromise results.
"The approval of Amyvid offers physicians a tool that, in conjunction with other diagnostic evaluations, can provide information to help physicians evaluate their patients," noted Avid CEO Daniel Skovronsky in a prepared statement.
Lilly has gambled huge sums on a late-stage program for solanezumab, a prospective Alzheimer's treatment which Bernstein's Tim Anderson has described as a "massive lottery ticket." The Phase III readout is due later this year. While the Amyvid approval may not be all that Lilly had initially hoped for, it is a step forward in what has been an agonizingly slow march to finding new and better ways to diagnose and treat patients.