Blood-Based P-Tau181 Testing for Alzheimer’s Pathology Now Cleared by the FDA for the Primary Care Setting

The Food and Drug Administration (FDA) has granted 510(k) clearance to Elecsys pTau181 (Roche, Basel, Switzerland), the first blood-based biomarker assay authorized to aid in the initial assessment of Alzheimer disease (AD) and other causes of cognitive decline for people aged ≥55 years in the primary care setting. The test measures levels of phosphorylated tau 181 (p-tau181) in blood plasma, a protein linked to amyloid plaque and tau pathology characteristic of AD. Elecsys pTau181 was previously cleared in 2022 by the FDA for the assessment p-tau181 in the cerebrospinal fluid (CSF) of people aged ≥55 years at risk of dementia and AD.

According to a statement from Roche, Elecsys pTau181 was developed in collaboration with Eli Lilly and Company to help clinicians rule out AD-related amyloid or tau pathology for individuals in the early stage of cognitive impairment. The test is intended to be used in the primary care setting to enable physicians to improve referral to specialty care, preserving neurologists’ resources and reducing the need for costly and invasive procedures such as PET and CSF testing.   

The FDA’s decision was based on data reported from a prospective, multicenter, noninterventional study evaluating Elecsys pTau181 in the assessment of 312 participants. Roche reported that Elecsys pTau181 demonstrated a 97.9% negative predictive value for ruling out AD-related pathology in a study population designed to mirror the real-world primary care setting in terms of an early stage of disease and low prevalence of AD.

Source: Roche. Roche’s Elecsys pTau181 becomes the only FDA-cleared blood test for use in primary care to rule out Alzheimer’s-related amyloid pathology. Roche. Published October 12, 2025. Accessed October 31, 2025. https://www.roche.com/investors/updates/inv-update-2025-10-13b