Clinicians will soon have more tools to help them identify potential Alzheimer’s disease in adults with cognitive impairment—in the past week the U.S. Food and Drug Administration (FDA) has cleared two new blood-based biomarker tests, including one approved for adults as young as 40.Why It’s Relevant
Until recently, clinicians could only identify Alzheimer’s-related brain pathology using expensive PET scans or invasive cerebrospinal fluid (CSF) tests. Last year, the FDA cleared the first two blood tests to aid in Alzheimer’s diagnosis, providing a more accessible option for patients. Doubling the number of validated blood tests will further increase accessibility while enabling clinicians to order a panel of different biomarker tests to confirm a diagnosis.
By the Numbers
- Cleared on August 24, Roche’s Elecsys Phospho-Tau Plasma (pTau217) blood test is billed as the first single biomarker, single assay, single cutoff test to both rule in or rule out Alzheimer’s in patients 55 and older in primary or secondary care settings. (Roche’s current tau test can only rule out a diagnosis.)
- The FDA’s clearance of pTau217 is supported by a large study involving 2,148 adults (ages 50 to 90) across four countries. The pTau217 test matched PET scan results conducted 12 months before or after the blood draw in 88% of cognitively impaired participants and 91% of unimpaired participants.
- On August 20, FDA cleared C2N Diagnostics’ PreclivityAD2 test, the first for use in adults as young as 40. PreclivityAD2 assesses the ratios of key beta amyloid and tau peptides associated with Alzheimer’s disease.
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PreclivityAD2’s clearance was supported by a study involving 1,142 adults with symptoms of cognitive decline. The test correctly ruled in 98% of those who had a positive result on a PET scan or CSF biomarker test and confirmed findings for 93% of those with a negative result.
The Other Side
Both newly cleared biomarker tests should be assessed in diverse, real-world cohorts to determine their applicability in routine clinical practice, particularly in primary care settings, where less is known about the performance of Alzheimer’s blood-based tests. Both tests are also designed only as aids in Alzheimer’s screening among adults already presenting with cognitive symptoms and are not to be used as standalone diagnostics.
Takeaway Message
As antibody-based treatments for Alzheimer’s disease are only approved for people with mild or moderate dementia, having a range of available blood tests that can detect abnormal brain pathology early could provide greater opportunities for individuals to receive disease-modifying treatments.
Related Information
Sources
Diagnostics.roche.com. Roche receives FDA clearance for Elecsys® pTau217, advancing Alzheimer’s disease assessment across primary and specialty care. Published August 24, 2026.
PreclivityAD.com. FDA clears C2N Diagnostics’ PrecivityAD2®—first Alzheimer’s blood test for adults with cognitive symptoms as young as 40. Published August 20, 2026.
(Image: Getty Images/iStock/ojos de hojalata)
