New Research Shows High Accuracy of Precivity™ Blood Biomarkers in the Evaluation of Brain Amyloid in Pre-Clinical Alzheimer's Disease
ST. LOUIS — Nov. 7, 2023 — C2N Diagnostics, LLC (C2N), a leader in advanced brain health diagnostics, announced new findings that its blood biomarkers Aβ42/Aβ40 (amyloid-beta) and p-tau217/np-tau217 (%p-tau217, or phosphorylated tau-217 divided by non-phosphorylated tau-217)[1] are helpful in improving the speed and efficiency of anti-amyloid prevention trials in individuals with pre-clinical Alzheimer’s disease. Both of these biomarkers are included in the company’s commercially available Precivity™ blood tests, which help healthcare providers determine the presence of amyloid plaques in the brain, a hallmark sign of Alzheimer’s disease, and aid in medical management and treatment decisions.
C₂N analyzed the biomarkers using its high-resolution mass spectrometry (MS) analytical platform as part of this study. These results were highlighted in the article ”Plasma Aβ42/Aβ40 and phospho-tau217 concentration ratios increase the accuracy of amyloid PET classification in preclinical Alzheimer's Disease,” published today in theonline edition of the journal Alzheimer’s & Dementia®. Robert Rissman, Ph.D., Professor of Physiology and Neuroscience and the W.M. Keck Endowed Professor in Medicine at the University of Southern California, led the study.
The purpose of this study was to determine the usefulness of MS-based measurements of plasma p-tau217, np-tau217, p-tau181, np-tau181, their concentration ratios, and Aβ42/Aβ40 ratio measurements to detect brain amyloid pathology versus the reference standard amyloid PET (positron emission tomography) in cognitively unimpaired individuals. The study evaluated 1,080 baseline plasma samples of participants who were recruited and screened for enrollment into the AHEAD 3-45 study of the anti-amyloid therapy lecanemab. All participants underwent amyloid PET scans, and 340 (32%) participants had positive PET scan findings (defined as Centiloid scale > 20). This study cohort was derived from cognitively unimpaired, high-risk individuals eligible for the AHEAD 3-45 study evaluating lecanemab.
Among the individual biomarkers evaluated, plasma p-tau217/np-tau217 had highest accuracy followed next by Aβ42/Aβ40 and last by p-tau181/np-tau181 for identifying amyloid PET status. Each of the biomarker ratio measures more robustly identified amyloid PET status when compared to their individual absolute concentration values of p-tau217, Ab42, and p-tau181.
The researchers wrote that “the best performance as indicated by AUC [Area Under the Receiver Operating Curve] was achieved when plasma p-tau217 and Aβ42/Aβ40 ratios were combined in a model that predicted cerebral amyloid PET status.” The combination of plasma p-tau217/np-tau217 and Aβ42/Aβ40, measured against amyloid PET achieved an AUC performance of 0.94 (95% CI; 0.93 – 0.96) and that performance marginally improved when also including age and APOE genetic status into the production model (AUC 0.95; 0.94-0.96).
“The cost and burden for researchers and research volunteers for studies into Alzheimer’s disease continues to rise. Any opportunity to streamline the recruitment and enrollment process is helpful given this scenario,” said Dr. Joel Braunstein, C₂N’s CEO and president. “The blood biomarkers with the highest performance in the study are the biomarkers highlighted in the Precivity blood tests, demonstrating the application of these biomarkers for important research purposes. In addition, healthcare specialists are currently using these biomarkers in our Precivity blood tests to help in the clinical evaluation of patients aged 55 years and older with concerns of cognitive impairment.”
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About C₂N Diagnostics, LLC
C₂N is a specialty diagnostics company with a vision to bring Clarity Through Innovation®. C₂N strives to provide exceptional laboratory services and products in the field of brain health. C₂N’s high-resolution mass spectrometry-based biomarker services and products are used for: clinical decision-making to improve patient care, including diagnosis and treatment monitoring; maximizing the quality and efficiency of clinical trials that test novel treatments for neurodegeneration; and providing innovative tools to help healthcare researchers better understand novel mechanisms of disease, identify new treatment targets, and conduct important epidemiologic studies to improve global public health. C₂N assays have been used in over 100 Alzheimer’s disease and other research studies throughout the U.S. and the world. This includes landmark treatment and prevention trials involving disease-modifying therapies (DMTs) that are changing the trajectory of Alzheimer’s disease. C₂N has ongoing collaborations with multi-national pharmaceutical and biotech companies, leading academic institutions, National Institute on Aging, Alzheimer’s Association, and other non-profits and consortiums. Over 15,000 Precivity™-related biomarker measures have been reported through peer-reviewed publications, with many more manuscripts currently under review.
About the Precivity Blood Tests
The PrecivityAD2™/PrecivityAD® blood tests are intended for use in patients aged 55 and older with signs or symptoms of mild cognitive impairment or dementia who are undergoing evaluation of Alzheimer’s disease or dementia.
The Precivity-ApoE™ blood test is indicated for use in adult patients for whom knowledge of apolipoprotein E2,E3,E4 allele status may be informative for medical management and treatment decisions. Only a healthcare provider can order the Precivity™ tests.
The tests are available in 49 states, the District of Columbia, and Puerto Rico; the exception is New York, which requires an individual state process for CLIA labs. C₂N is working toward obtaining the requisite certification that will permit the PrecivityAD® test to be available in New York in the near future.
The company acknowledges generous support from National Institute on Aging, GHR Foundation, Alzheimer’s Drug Discovery Foundation, BrightFocus Foundation and Alzheimer’s Association. For more information visit www.C2N.com.
COMPANY CONTACT:
Joni Henderson
JHenderson@c2n.com
314-464-0009
MEDIA CONTACT:
Adam Shapiro
202-427-3603
[1] The p-tau217/np-tau217 assay leveraged in the study represents a prior validated version of the one currently incorporated into the PrecivityAD2™ blood test as %p-tau217; the analytical and clinical performance characteristics of both versions have been established by C₂N Diagnostics to be equivalent.