Quanterix backs tau for Alzheimer’s diagnosis

 A blood test for amyloid to help diagnose Alzheimer’s disease, C2N Diagnostics’ PrecivityAD, has been available for nearly two years. Yesterday the first blood test for a different Alzheimer’s biomarker, tau, was made available for the same purpose. Quanterix has launched an assay that can quantitatively measure pTau-181 as a lab-developed test – without FDA approval or clearance – and doctors can now use this to help evaluate adults suspected of having Alzheimer’s. Like the amyloid assay, Quanterix’s test must be used in combination with other diagnostic criteria such as cognitive assessments and imaging. Data from a validation study of the test will be presented at the Alzheimer’s Association International Conference in the next few days. Several other tau tests are on sale in various countries, but only to aid in Alzheimer’s research rather than for use in the clinic. Perhaps the likeliest to gain formal US approval at some point is Roche’s Elecsys Amyloid Plasma Panel, which confusingly does not actually test for amyloid. Not only does Roche generally prefer to get the FDA’s blessing before launching its tests, but this tau and ApoE4 assay gained US breakthrough designation last week.

Selected tests for tau
Company	Test	Sample	Availability
Quanterix	p-Tau181 plasma test	Blood	Launched Jul 2022 to aid in Alzheimer's diagnosis
Quanterix	Simoa P-Tau181 V2 kit	Blood	Launched May 2020 for research only
Quanterix	Neurology 3-Plex A assay, tests for total tau, amyloid beta (1-40 & 1-42)	CSF and blood	Launched May 2019 for research only
Roche	Elecsys Amyloid Plasma Panel, tests for p-Tau181 and apolipoprotein E4	Blood	Granted US breakthrough status Jul 2022
C2N Diagnostics	P-Tau Multi-Analyte assay	Blood	Launched May 2022 for research only
Fujirebio	Lumipulse G pTau181 Plasma assay	Blood	Launched Mar 2022 for research only
Lilly	P-tau217 test	Blood	Used in-house to aid trials of Alzheimer's drugs
Source: company releases and websites. https://www.evaluate.com/vantage/articles/news/corporate-strategy-snippets/quanterix-backs-tau-alzheimers-diagnosis