FDA Clears First Blood Test to Rule Out Alzheimer-Related Pathology in Primary Care

Roche announced today the FDA clearance of its Elecsys pTau181 test, marking the first blood-based biomarker specifically indicated to aid the initial assessment for Alzheimer disease (AD) and related causes of cognitive decline within the primary care setting.¹

The Elecsys pTau181 test measures phosphorylated tau (pTau 181) protein in plasma—a key biomarker for AD, including amyloid plaque and tau aggregate presence—and is intended for adults aged 55 and older presenting with signs or symptoms of cognitive decline.¹

Clinical performance of the Elecsys pTau181 test was confirmed in a multicenter, noninterventional study involving 312 participants. In an early-disease, low-prevalence population reflective of primary-care settings, the test achieved a 97.9% negative predictive value (NPV) to rule out AD-associated amyloid pathology, according to Roche. The company emphasized that the result should always be interpreted alongside other clinical information.¹

“By bringing Alzheimer’s blood-based biomarker testing into primary care, we can help patients and their clinicians get answers sooner to support them earlier in their journeys," Brad Moore, president and CEO of Roche Diagnostics North America, said in a statement. "This milestone reflects Roche’s leadership in diagnostics and our commitment to expanding access to innovative testing for patients and their clinicians.”¹

Roche developed the test in collaboration with Eli Lilly and Company, and more than 4,500 Roche instruments are already installed in laboratories across the United States, supporting rapid integration into health systems.

AD affects more than 7 million Americans, yet diagnostic barriers leave up to 75% of symptomatic individuals undiagnosed, with those who receive a diagnosis waiting nearly 3 years on average after symptom onset. Among patients with mild cognitive impairment or early-stage symptomatic disease, 92% remain undiagnosed and are unable to determine potential treatment options. Confirmatory testing for amyloid pathology, ie, positron emission tomography (PET) or cerebrospinal fluid (CSF) analysis, is invasive, costly, and difficult to access.

The Elecsys pTau181 blood test offers primary care clinicians a minimally invasive way to rule out AD-related amyloid pathology, potentially reducing unnecessary PET or CSF testing and guiding referrals so that neurologists can focus on patients most likely to require advanced evaluation and treatment.

Roche affirmed ongoing work to transform diagnostics and further advance technologies supporting earlier and more accurate detection of neurological diseases, both in the United States and globally, as highlighted by recent CE Mark certification for the test in Europe.²

References

1. Roche’s Elecsys pTau181 becomes the only FDA-cleared blood test for use in primary care to rule out Alzheimer’s-related amyloid pathology. News release. Roche Diagnostics. October 13, 2025. Accessed October 13, 2025. https://diagnostics.roche.com/us/en/news-listing/2025/fda-cleared-ptau181-alzheimers-blood-test.html
2. Roche receives CE Mark for minimally invasive blood test to help rule out Alzheimer’s disease. News release. Roche Diagnostics. July 23, 2025. Accessed October 13, 2025. https://www.globenewswire.com/news-release/2025/07/23/3119980/0/en/Roche-receives-CE-Mark-for-minimally-invasive-blood-test-to-help-rule-out-Alzheimer-s-disease.html