FDA Approves New PET Radiotracer For Dementia

The U.S. Food and Drug Administration (FDA) today announced its approval of Vizamyl for the evaluation of Alzheimer’s disease and dementia.

Also known as the flutemetamol F 18 injection, Vizamyl is a radioactive diagnostic drug that is used with positron emission tomography (PET) imaging for evaluation in adults. It is the first drug to create color images for visual assessment instead of black-and-white. Vizamyl is the second such drug the FDA has approved in as many years – the agency green-lighted Amyvid (Florbetapir F 18 injection) in 2012.

Alzheimer’s-related dementia is caused by the build-up in the brain of the abnormal protein beta amyloid. Ordinarily, beta amyloid is broken down and eliminated from the body, but in patients with Alzheimer’s or dementia, the protein accumulates and damages and kills brain cells.

“Many Americans are evaluated every year to determine the cause of diminishing neurologic functions, such as memory and judgment, that raise the possibility of Alzheimer’s disease,” said Shaw Chen, MD, deputy director of the Office of Drug Evaluation IV in the FDA’s Center for Drug Evaluation and Research, in a written statement. “Imaging drugs like Vizamyl provide physicians with important tools to help evaluate patients for AD and dementia.” 

Vizamyl is manufactured by Medi-Physics, Inc., in Arlington Heights, Ill., for GE Healthcare. It will be commercially available in 2014.

GE Healthcare Life Sciences President and CEO Kieran Murphy said, in a press release, the company hopes the introduction of Vizamyl will augment treatment options and identify patients who could most benefit from clinical trials.

While Vizamyl doesn’t replace other existing diagnostic tests for Alzheimer’s and dementia, it does contribute to the evaluation of the brain. The drug produces at PET brain image by attaching itself to beta amyloid. Positive scans point to moderate-or-greater presence of beta amyloid in the brain. Negative scans indicate no beta amyloid is present.

The FDA also noted that Vizamyl is not indicated to predict the development of Alzheimer’s or to assess how patients are responding to treatment for Alzheimer’s. Only providers who have been specifically trained in an imaging interpretation program should read these scans. The drug labeling provides information about image interpretation.

GE conducted two clinical studies, including 384 participants with varying degrees of cognitive functioning, to demonstrate Vizamyl’s efficacy. All participants received Vizamyl injections and were scanned. Five independent readers interpreted the images after all clinical information was removed, and several scan results were confirmed via autopsy.

According to the FDA announcement, study results showed Vizamyl correctly identifies beta amyloid in the brain and that trained readers can successfully interpret the scans. The drug’s safety was confirmed in 761 participants, but side effects, including hypersensitivity reactions, flushing, headache, hypertension, nausea, and dizziness, are possible.