What two newly cleared blood tests can tell clinicians about Alzheimer’s

A September 18 JAMA news report highlighted two additional blood tests cleared by the US Food and Drug Administration to assist the assessment of Alzheimer’s-related pathology. FDA records date both clearance decisions to August 19, 2026; September was the date of the selected news coverage.

C2N Diagnostics’ PrecivityAD2 is intended for adults aged 40 and older who have signs or symptoms of cognitive impairment and are being evaluated for Alzheimer’s or another cause of cognitive decline. Its blood measurements are combined into a score that helps clinicians assess the likelihood of amyloid pathology.

Roche’s Elecsys Phospho-Tau (217P) Plasma test measures p-tau217 and is intended for people aged 55 and older with signs, symptoms or complaints of cognitive decline. Roche describes results in positive, intermediate and negative categories, interpreted alongside other clinical information.

Neither test replaces a clinical assessment. PrecivityAD2’s FDA documentation explicitly excludes screening and stand-alone diagnosis. Roche likewise says its test should not be used alone, and that its ability to predict future dementia has not been established. These are tools for investigating cognitive concerns, rather than a general forecast of a healthy person’s future.

Sources:

• JAMA: FDA Approves 2 New Alzheimer Disease Blood Tests

• FDA: PrecivityAD2 clearance record K253240

• FDA: PrecivityAD2 indications for use

• FDA: Elecsys pTau217 clearance record K261686

• Roche: Elecsys pTau217 clearance and intended use