FDA Grants Market Clearance to Diagnostic Blood Test for Alzheimer Disease

The FDA has cleared for marketing the Lumipulse G pTau217/ß-Amyloid 1-42 Plasma Ratio blood test (Fujirebio Diagnostics, Inc.) to aid in the diagnosis of Alzheimer disease. The test is used for the early detection of amyloid plaques in adults aged 55 years or older who are exhibiting signs and symptoms of the disease. The device was previously granted a breakthrough device designation on May 4, 2022, according to the FDA.^1,2

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Alzheimer disease is a brain disorder known to slowly destroy a patient’s memory and thinking skills and, eventually, the ability to carry out simple tasks. It is a progressive disease that worsens over time. In most people with Alzheimer disease, clinical symptoms first appear later in life, such as through amyloid plaques in the brain. Although these plaques can occur in other diseases, being able to detect the presence of plaque—along with other evaluations—can assist health care professionals in determining and diagnosing the probable cause of the patient’s symptoms and findings. Amyloid plaques can be detected and visualized via amyloid positron emission tomography (PET) brain scans—sometimes years before clinical symptom onset—to aid in the diagnosis of the disease.¹

The Lumipulse test measures 2 proteins, pTau217 and β-amyloid 1-42, both of which are found in human plasma—a component of blood—and calculates the numerical ratio of the levels of the 2 proteins. These ratios are correlated to the presence or absence of amyloid plaques in the patient’s brain, reducing the need for a PET scan. The Lumipulse test only requires a simple blood draw, making it less invasive and much easier for patients to access. Other FDA-cleared or authorized tests—one of which is also manufactured by Fujirebio—are used with cerebrospinal fluid (CSF) samples collected via spinal tap, which can be invasive for patients.¹

“Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined,” Martin A. Makary, MD, MPH, FDA Commissioner, 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.”¹

Data from a multicenter clinical trial of 499 adults who were considered cognitively impaired showed that approximately 91.7% of individuals tested with the Lumipulse test who had positive results also had PET scan or CSF test results indicating the presence of amyloid plaques. Additionally, 97.3% of those who had negative results also had negative amyloid PET scan or CSF test results. Notably, less than 20% of the total population enrolled in the study received an “indeterminate” Lumipulse test result.¹

Further, a study published in Alzheimer’s & Dementia³ featuring the Lumipulse in 391 patients from a clinic cohort and 121 from a community cohort shows that the device demonstrated high performance for abnormal statuses of Aβ PET (area under the curve [AUC]: 0.963–0.966) and tau PET (AUC: 0.947–0.974). These were considered clinically equivalent to those of CSF p‐tau181/Aβ42 and Aβ42/Aβ40 and higher than those of blood p‐tau217, Aβ42/Aβ40, p‐tau181, and p‐tau181/Aβ42 in both clinic and community cohorts, the study authors wrote. By applying a 2‐cutoff approach, the specificity of the test was improved without reducing sensitivity. In addition, the p‐tau217/Aβ42 ratio had a lower intermediate percentage than p‐tau217 alone in both clinic (10.6% vs 13.0%, respectively) and community (16.5% vs 31.4%, respectively) cohorts.³

Another study published in Fluids and Barriers of the CNS⁴ had found statistically significant positive correlations between CSF and plasma Aβ42, Aβ42/Aβ40 ratio, and pTau181. All the biomarkers—except Aβ40—showed differences in patients who were A+ vs A-; A+T+ vs A-T-; and A+T- vs A-T-. Notably, Aβ42 and Aβ42/Aβ40 plasma levels were lower in A+T- compared with the A-T- and A-T+ groups, and pTau181 and pTau217 plasma levels were higher in A+T+ compared with A+T-. Aβ42/Aβ40 and pTau217 were also observed to have a robust performance in differentiating patients who were A+ from A- (AUC = 0.857 and 0.862, respectively) and A+T+ from A-T- (AUC = 0.866 and 0.911).⁴

These findings, according to the FDA, indicate that the Lumipulse blood test has reliability in the prediction of amyloid pathology presence or absence in patients who are cognitively impaired. Further, the test is intended for patients presenting at a specialized care setting with signs and symptoms of cognitive decline.¹

“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 news release. “[This] clearance is an important step for Alzheimer’s disease diagnosis, making it easier and potentially more accessible for U.S. patients earlier in the disease.”¹

REFERENCES

1. US Food and Drug Administration. FDA Clears First Blood Test Used in Diagnosing Alzheimer’s Disease. News release. May 16, 2025. Accessed May 19, 2025. https://www.fda.gov/news-events/press-announcements/fda-clears-first-blood-test-used-diagnosing-alzheimers-disease

2. US Food and Drug Administration. Breakthrough Devices Program. Accessed May 19, 2025. https://www.fda.gov/medical-devices/how-study-and-market-your-device/breakthrough-devices-program

3. Wang J, Huang S, Lan G, et al. Diagnostic accuracy of plasma p-tau217/Aβ42 for Alzheimer's disease in clinical and community cohorts. Alzheimers Dement. 2025;21(3):e70038. doi:10.1002/alz.70038

4. Catania M, Battipaglia C, Perego A. et al. Exploring the ability of plasma pTau217, pTau181 and beta-amyloid in mirroring cerebrospinal fluid biomarker profile of Mild Cognitive Impairment by the fully automated Lumipulse^® platform. Fluids Barriers CNS. 22, 9 (2025). doi:10.1186/s12987-025-00620-5