FDA Clears PrecivityAD2 Blood Test for Amyloid Detection in Symptomatic Adults 40+
FDA clearance of PrecivityAD2 offers a less invasive option for confirming brain amyloid in symptomatic adults but remains adjunctive to clinical assessment. The 1,142-person study demonstrated high rule-in and rule-out values against established references, yet generalizability beyond memory clinics is untested. Broader uptake depends on real-world validation and payer coverage.
The clearance permits the mass spectrometry assay measuring amyloid-beta 42/40 ratio and phosphorylated tau 217 to aid clinicians evaluating patients already presenting memory concerns. It is not approved for asymptomatic screening or standalone diagnosis. The pivotal dataset compared blood results directly to amyloid PET visual reads and CSF biomarker thresholds, yielding 93.1% negative predictive value overall.
Real-world performance will likely differ because the study population was enriched for memory-clinic referrals rather than primary care. Earlier plasma-tau studies in NEJM and JAMA Neurology showed similar rule-in accuracy but documented 15-20% discordance when applied outside specialist centers. Health-system adoption may therefore hinge on reimbursement policies that currently favor CSF or PET for anti-amyloid therapy eligibility.
If post-market surveillance confirms stable predictive values below age 65 and in diverse ancestries, the test could reduce lumbar punctures by roughly 60% in initial work-ups. Next required studies are pragmatic RCTs measuring time-to-diagnosis and downstream treatment rates versus standard pathways.
C2N Diagnostics: At least 75,000 U.S. tests ordered within 18 months of launch.
Sources (2)
- [1]FDA 510(k) Clearance Summary for PrecivityAD2(https://www.fda.gov/medical-devices)
- [2]Plasma p-tau217 Accuracy in Symptomatic Cohorts(https://www.nejm.org/doi/10.1056/NEJMoa2314114)