FDA Grants Clearance to Two New Blood Tests for Alzheimer's Assessment
核心洞察
The FDA cleared C2N Diagnostics (搜索)' PrecivityAD2 (搜索) and Roche's Elecsys pTau217 (搜索) plasma test for assessing amyloid pathology in patients with cognitive symptoms.
PrecivityAD2 (搜索) is the first FDA-cleared Alzheimer's blood test indicated for symptomatic adults aged 40 and older, with 97.6% positive predictive value in validation.
Roche's Elecsys pTau217 (搜索), developed with Eli Lilly, is cleared for adults 55 and older and runs on the installed cobas laboratory infrastructure.
The US FDA has cleared two new blood tests to help clinicians assess whether patients with cognitive symptoms have brain changes associated with Alzheimer's disease (搜索), bringing the number of FDA-cleared Alzheimer's blood tests to four. The newly cleared tests are PrecivityAD2 (搜索) from C2N Diagnostics (搜索) and Elecsys Phospho-Tau (217P) Plasma (pTau217) from Roche, developed in collaboration with Eli Lilly. The clearances were announced in August 2026. They join the Lumipulse G pTau217/β-Amyloid 1-42 Plasma Ratio, cleared in May 2025, and the Elecsys pTau181 plasma test, cleared in October 2025.
Both new tests are intended to help identify amyloid pathology, one of the biological hallmarks of Alzheimer's disease (搜索), but neither is designed to diagnose the disease on its own. Results are meant to be interpreted alongside symptoms, medical history and other clinical findings. PrecivityAD2 (搜索) is the first FDA-cleared Alzheimer's blood test indicated for symptomatic adults aged 40 and above. It measures the amyloid-beta (搜索) (Aβ) 42/40 ratio and the p-tau217 (搜索)/np-tau217 ratio, combining them through an algorithm called the Amyloid Probability Score 2 (APS2). In a validation study of 1,142 people with cognitive symptoms, it recorded a positive predictive value of 97.6% and a negative predictive value of 93.1% against reference methods including amyloid PET and CSF biomarkers. C2N said the FDA-cleared version is expected to become available later in 2026; a laboratory-developed version is currently offered under CLIA.
Roche's Elecsys pTau217 (搜索) measures the pTau217 biomarker in blood and is intended for adults aged 55 and older with signs, symptoms or complaints of cognitive decline. Roche said it is the first FDA-cleared single-biomarker blood test designed to support both rule-in and rule-out assessment of amyloid pathology in this age group, returning positive, intermediate or negative results. It runs on Roche's existing cobas laboratory infrastructure, with more than 4,500 instruments installed in US laboratories. In a study of more than 2,100 adults, blood test results agreed with amyloid PET findings in approximately 88% of people with cognitive impairment and 91% of those without. Both companies emphasise that the tests should be used as part of a broader clinical assessment, and clinicians have cautioned that performance in younger patients should be interpreted carefully given limited data in people in their 40s.
Source: Daijiworld