May 6, 2022 – The U.S. Food and Drug Administration today permitted marketing for the first in vitro diagnostic test for early detection of amyloid plaques associated with Alzheimer’s disease. The Lumipulse G β-Amyloid Ratio (1-42/1-40) test is intended to be used in adult patients, aged 55 years and older, presenting with cognitive impairment who are being evaluated for Alzheimer’s disease and other causes of cognitive decline.
According to the National Institutes of Health, more than six million Americans, most age 65 or older, may have dementia caused by Alzheimer’s disease, a brain disorder known to slowly destroy memory and thinking skills, and, eventually, the ability to carry out the simplest tasks. In most people with Alzheimer’s disease, clinical symptoms first appear later in life.
Alzheimer’s disease is progressive, meaning that the disease gets worse over time. Early and accurate diagnosis is important to help patients and caregivers with planning and early treatment options. There is an unmet need for a reliable and safe test that can accurately identify patients with amyloid plaques consistent with Alzheimer’s disease. While amyloid plaques can occur in other diseases, being able to detect the presence of plaque, along with other evaluations, helps the doctor determine the probable cause of the patient’s symptoms and findings. Prior to today’s authorization, doctors used positron emission tomography (PET) scans, a potentially costly and cumbersome option, to detect/visualize amyloid plaques in a patient’s brain, often years before clinical symptom onset, to aid in diagnosing Alzheimer’s disease.
The Lumipulse test is intended to measure the ratio of β-amyloid 1-42 and β-amyloid 1-40 (specific proteins that can accumulate and form plaques) concentrations found in human cerebral spinal fluid (CSF), which can help physicians determine whether a patient is likely to have amyloid plaques, a hallmark sign of Alzheimer’s disease. Results must be interpreted in conjunction with other patient clinical information.
A positive Lumipulse G β-amyloid Ratio (1-42/1-40) test result is consistent with the presence of amyloid plaques, similar to what would be seen in a PET scan. A negative result is consistent with a negative amyloid PET scan result. 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 test is not intended as a screening or stand-alone diagnostic assay. There is also the possibility that a positive test result could be seen in patients with other types of neurologic conditions, as well as in older cognitively healthy people, which underscores the importance of using this test in conjunction with other clinical evaluations.
The FDA evaluated the safety and effectiveness of this test in a clinical study of 292 CSF samples from the Alzheimer’s Disease Neuroimaging Initiative sample bank. The samples were tested by the Lumipulse G β-amyloid Ratio (1-42/1-40) and compared with amyloid PET scan results. In this clinical study, 97% of individuals with Lumipulse G β-amyloid Ratio (1-42/1-40) positive results had the presence of amyloid plaques by PET scan and 84% of individuals with negative results had a negative amyloid PET scan.