The U.S. Food and Drug Administration (FDA) has granted clearance to Fujirebio Diagnostics to market for clinical use the first in vitro diagnostic (IVD) test designed to detect amyloid plaques associated with the development of Alzheimer's disease.
The FDA granted clearance under its breakthrough device pathway to Fujirebio's Lumipulse G β-Amyloid Ratio (1-42/1-40) test, which is designed to measure the ratio of β-amyloid 1-42 and β-amyloid 1-40. These are proteins that can accumulate and form plaques in the brain; concentrations of these proteins can be detected in cerebral spinal fluid (CSF).
The assay can help physicians determine whether a patient is likely to have amyloid plaques, which are widely seen as an indication of Alzheimer's disease. The FDA advised that the results of the Lumipulse assay should be interpreted with other clinical information from patients; the test is not intended as a screening or standalone diagnostic assay.
In announcing the clearance, the FDA said that results of the assay are similar to what could be seen in a PET scan, and a negative result on the IVD test is consistent with a negative PET scan of amyloid concentration.
"A negative test result reduces the likelihood that a patient's cognitive impairment is due to Alzheimer's disease, enabling physicians to pursue other causes of cognitive decline and dementia," the FDA noted.
The agency further cautioned that there is a possibility that the test could generate positive results in patients with neurologic conditions other than Alzheimer's disease -- and even in cognitively healthy individuals. This highlights the need to use the test with other clinical tools, the agency noted.
The FDA said it evaluated the safety and efficacy of the Lumipulse test in a clinical study that included 292 samples of CSF fluid that were acquired as part of the Alzheimer's Disease Neuroimaging Initiative (ADNI). These samples were tested with the Lumipulse G β-Amyloid Ratio test and compared to results from PET scans.
In all, 97% of individuals who had positive results with the Fujirebio assay also had positive amyloid accumulation that was visible on PET scans, and 84% of people with negative results on the assay also had negative PET scans.
The main risk of the Fujirebio assay is that it could generate false-positive and false-negative results, according to the FDA, which could lead to psychological distress, delay in receiving a correct diagnosis, and expense and risk from unnecessary treatment. For this reason, the agency has advised using the assay in conjunction with other tests.
Finally, the FDA noted that the Lumipulse test was evaluated through the agency's de novo premarket review pathway, designed for novel technologies that are low to moderate risk. The agency's approval of the test creates a new regulatory pathway for other products of a similar type, meaning these applications can be approved by simply demonstrating that they are substantially equivalent to the Lumipulse test.
"With the Lumipulse test, there is a new option that can typically be completed the same day and can give doctors the same information regarding brain amyloid status, without the radiation risk, to help determine if a patient's cognitive impairment is due to Alzheimer's disease," said Dr. Jeff Shuren, director of the FDA's Center for Devices and Radiological Health, in a statement.