Novel Plasma Assays That Selectively Detect Tau Characteristics Will Refine Clinical Study of Alzheimer Disease
The 2 new plasma assays to enhance Alzheimer’s disease research will support disease staging, predicting disease progression, and monitoring treatment outcome.
C2N Diagnostics has introduced 2 new plasma-based assays designed for research on Alzheimer disease (AD) pathology and progression. Developed and launched for research use only, the eMTBR-tau243 blood test and the C2N %p-tau MAA will provide investigators with more precise tools for assessing tau-related changes in the brain, according to a C2N statement.
Courtesy of C2N Diagnostics
The C2N eMTBR-tau243 assay detects a specific endogenous microtubule binding region fragment of tau that closely tracks insoluble tau aggregates within neurofibrillary tangles. According to C2N, research shows this marker may help improve diagnostic evaluation of AD pathology in clinical trials by supporting disease staging, predicting progression and treatment response, and monitoring treatment efficacy. The new plasma-based format builds on a eMTBR-tau243 cerebrospinal fluid test launched approximately 2 years ago, C2N said.
“Patients and families worried about Alzheimer’s disease are pressing on the entire healthcare sector for a clearer picture of Alzheimer’s disease pathology,” C2N CEO and President Joel Braunstein, said in the statement. “We are responding, first for researchers and then for the broader global healthcare provider community.”
The %p-tau MAA uses high-resolution LC-MS/MS to quantify 6 tau-related analytes, including %p-tau181, %p-tau205, and %p-tau217. By measuring both phosphorylated and nonphosphorylated tau from a single sample, the assay can calculate ratios that, according to C2N, help control for confounding factors such as age and comorbidities like kidney disease. In a large study published in JAMA last summer,2 C2N’s PrecivityAD2 test accuracy was unaffected in older patients and those with more comorbidities in a primary care setting.
C2N expects the new assays to be valuable in biopharma trials by covering both early- and late-stage tau pathology, improving disease identification, staging, and stratification.
C2N assays have been used in more than 150 AD and other research studies globally, according to the company. This includes landmark treatment and prevention trials involving disease-modifying therapies "that are changing the trajectory of Alzheimer’s disease."
The company’s current clinical Precivity blood tests, which detect amyloid plaques and inform management decisions, include PrecivityAD, PrecivityAD2, and Precivity-ApoE.
References
C2N Diagnostics expands portfolio of blood tests for clinical researchers studying Alzheimer’s disease and related dementia. News release. C2N Diagnostics. July 15, 2025. Accessed August 8, 2025. https://c2n.com/news-releases/c2n-diagnostics-expands-portfolio-of-blood-tests-for-clinical-researchers-studying-alzheimers-disease-and-related-dementiasnbsp
Palmqvist S, Tideman P, Mattsson-Carlgren N, et al. Blood biomarkers to detect Alzheimer disease in primary care and secondary care. JAMA. Published online July 28, 2024. doi:10.1001/jama.2024.13855
Alzheimer’s disease blood tests could improve diagnosis in primary care, speed recruiting for research and reduce wait times. News release. Alzheimer's Association. July 28, 2024. Accessed July 29, 2024. https://aaic.alz.org/releases-2024/blood-tests-alzheimers-biomarkers.asp
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