The Food and Drug Administration (FDA) has granted Breakthrough Device Designation for a brain amyloidosis blood test (C2N Diagnostics, St. Louis, MO) that screens patients for risk of Alzheimer’s disease. If approved by the FDA, the test could become the first blood-based screening test to predict brain amyloid PET scan results in adults with memory complaints or dementia. 

The test will provide an initial screening to help doctors determine the need for further diagnostic testing. Another form of screening, amyloid PET imaging, is costly, difficult to access, and exposes individuals who do not have Alzheimer’s disease to unnecessary radiation. The new test is a blood-based, in vitro diagnostic designed to predict amyloid PET scan results. 

The test combines into a ratio the concentration of amyloid beta (Aβ) isoforms Aβ42 and Aβ40 in human plasma, as measured by mass spectrometry. Studies have shown that a lower plasma Aβ42/Aβ40 ratio correlates with brain amyloidosis determined by amyloid PET scans.

The FDA approval coincides with the launch of the pivotal PARIS Study (Plasma Test for Amyloid Risk Screening), a clinical trial that is evaluating and validating the diagnostic performance of the blood test. 

“A vital medical need exists for a simple, radiation-free, non-invasive, less costly diagnostic test for the initial broad screening of individuals with subjective memory concerns,” said Dr. Joel Braunstein, CEO of C₂N Diagnostics. “The best chance we have for treating Alzheimer’s disease will come from earlier detection and, thus, earlier intervention. A simple, safe, blood-based screening test would be the first step in a multi-stage Alzheimer’s disease diagnostic process. It would improve the speed and efficiency of the overall diagnostic process, and also afford significant cost savings to healthcare systems.”