FDA Clears First Diagnostic Blood Test for AD

The US Food and Drug Administration (FDA) has granted 510(k) clearance to the first blood test to aid in diagnosing Alzheimer’s disease (AD). 

The Lumipulse G pTau217/Beta-Amyloid 1-42 Plasma Ratio, from Fujirebio Diagnostics, Inc., is for the early detection of amyloid plaques associated with AD in adults aged 55 years and older who show signs and symptoms of the disease.

“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined,” FDA Commissioner Martin A. Makary, MD, MPH, said in a news release. 

“Knowing that 10% of people aged 65 and older have Alzheimer’s, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients.” 

The Lumipulse G pTau217/Beta-Amyloid 1-42 Plasma Ratio calculates the ratio of the levels of pTau217 and Beta-amyloid 1-42 in plasma. This ratio is correlated to the presence or absence of amyloid plaques in the brain, reducing the need for a PET scan.

In 2022, the FDA approved the Lumipulse G Beta-Amyloid Ratio (1-42/1-40), also from Fujirebio Diagnostics, which measures the ratio of Beta-amyloid 1-42 and Beta-amyloid 1-40 concentrations in human cerebrospinal fluid (CSF), as reported by Medscape Medical News. 

This new Lumipulse test only requires a simple blood draw, making it less invasive and easier for patients to access.

In reviewing the Lumipulse G pTau217/Beta-Amyloid 1-42 Plasma Ratio, the FDA evaluated data from a multicenter clinical study of 499 individual plasma samples from adults who were cognitively impaired. The samples were tested by the Lumipulse blood test and compared with amyloid PET scan or CSF test results.

The study showed that 91.7% of individuals with positive blood test results had evidence of amyloid plaques by a PET scan or CSF test, and 97.3 % of individuals with negative blood test results had a negative amyloid PET scan or CSF test result. Fewer than 1 in 5 patients tested received an indeterminate Lumipulse blood test result.

“These findings indicate that the new blood test can reliably predict the presence or absence of amyloid pathology associated with Alzheimer’s disease at the time of the test in patients who are cognitively impaired,” the FDA said in the release. 

The test is intended for patients presenting to specialized care settings with signs and symptoms of cognitive decline. The results must be interpreted in conjunction with other patient clinical information.

The Lumipulse G pTau217/Beta-Amyloid 1-42 Plasma Ratio is not intended as a screening or stand-alone diagnostic test and other clinical evaluations or additional tests should be used for determining treatment options.

The Lumipulse G pTau217/Beta-Amyloid 1-42 Plasma Ratio was granted breakthrough device designation.

“Nearly 7 million Americans are living with Alzheimer’s disease, and this number is projected to rise to nearly 13 million,” Michelle Tarver, MD, PhD, director of the Center for Devices and Radiological Health, said in the release. 

Clearance of the Lumipulse blood test is “an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for US patients earlier in the disease,” Tarver added.