In a multicenter study of 312 participants, Roche’s Elecsys pTau181 blood test accurately ruled out Alzheimer’s-related amyloid pathology in primary care with a 97.9% negative predictive value.

Roche announced that the US Food and Drug Administration has cleared the Elecsys pTau181 assay, the first and only blood-based biomarker test authorized for use in primary care to aid in ruling out Alzheimer’s disease–related amyloid pathology. The Elecsys pTau181 assay quantifies phosphorylated tau 181 (pTau181) in plasma, a biomarker associated with amyloid and tau pathology characteristic of Alzheimer’s disease. It is indicated for patients aged 55 years and older presenting with cognitive symptoms or complaints and is designed to assist clinicians in the initial evaluation of cognitive decline.

Developed by collaborating with Eli Lilly and Company, the test provides a minimally invasive option for early assessment of cognitive impairment. It assists in identifying patients unlikely to have Alzheimer’s-related amyloid pathology, allowing clinicians to focus referrals on those who may require advanced neurologic evaluation or treatment.

The assay is fully automated and compatible with Roche’s existing network of more than 4,500 diagnostic instruments in US laboratories, facilitating rapid implementation without significant infrastructure changes. By integrating this testing capability into primary care, clinicians may be able to streamline diagnostic pathways, improve referral quality, and preserve specialist resources. The approach may also reduce reliance on more invasive and costly diagnostic modalities, such as positron emission tomography or cerebrospinal fluid analysis.

The US Food and Drug Administration clearance in the US follows CE Mark certification in Europe, where Elecsys pTau181 became the first In Vitro Diagnostic Regulation–certified blood test to aid in ruling out Alzheimer’s-associated amyloid pathology.

Source: Roche Diagnostics