Use of florbetaben, a PET tracer, to detect beta-amyloid plaques in the brain may help doctors diagnose Alzheimer’s disease (AD) earlier, according to research to be presented as part of the emerging science program at the American Academy of Neurology’s 64 th annual meeting in New Orleans, April 21-28.
The aim of the global Phase III trial was to confirm that florbetaben can detect beta-amyloid in vivo, and compare the results of the scans against post mortem specimens. Currently, AD can only be definitively confirmed through the detection of amyloid plaques during autopsy.
Florbetaben is an 18F-labeled PET tracer that binds specifically to beta-amyloid deposits. A Phase II study had previously shown patients with a clinical diagnosis of AD could be differentiated from healthy, age-matched controls on the basis of florbetaben uptake in the brain.
More than 200 participants nearing death, either with suspected AD or without known dementia, participated in the study. All participants agreed to donate their brain and undergo MRI and florbetaben PET scans. Thirty-one participants reached autopsy and the amount of plaque in their brains was compared to the results of the scans. A total of 186 brain regions from these donors was analyzed along with 60 brain regions from healthy volunteers.
Results of a regional comparison showed that florbetaben detected beta-amyloid with a sensitivity of 77 percent and a specificity of 94 percent. Comparison of the visual assessment method proposed for florbetaben for clinical practice with post-mortem diagnosis showed a sensitivity of 100 percent and a specificity of 92 percent.
“These results confirm that florbetaben is able to detect beta-amyloid plaques in the brain during life with great accuracy and is a suitable biomarker,” Marwan Sabbagh, MD, director of Banner Sun Health Research Institute in Sun City, Ariz., said in a statement. “This is an easy, non-invasive way to assist an Alzheimer’s diagnosis at an early stage. Also exciting is the possibility of using florbetaben as tool in future therapeutic clinical research studies where therapy goals focus on reducing levels of beta-amyloid in the brain.”
The study was supported by Bayer Healthcare Berlin. Piramal Healthcare signed an agreement to acquire the worldwide rights to the molecular imaging research and development portfolio of Bayer Pharma, including rights to florbetaben, on April 16.