Researchers Identify New Cost Savings and Accuracy of C₂N Diagnostics’ Blood Tests to Enable Healthcare Providers to Better Identify Alzheimer’s Disease
Findings Presented at 16th Clinical Trials on Alzheimer's Disease Conference
ST. LOUIS — Nov. 16, 2023 — Scientists, clinicians, and others taking part in the 16th Clinical Trials on Alzheimer's Disease (CTAD) conference learned the latest insights about C2N Diagnostics, LLC’s Precivity™ line of blood teststo facilitate earlier and more accurate diagnosis of Alzheimer’s disease pathology by healthcare providers. CTAD attendees heard about clinical and analytical data relating to C₂N’s proprietary portfolio at 10 sessions and from three scientific posters.
PrecivityAD® Blood Test Showed Economic Utility in the Evaluation of Cognitive Impairment.
C₂N Senior Medical Advisor Dr. Mark Monane presented details about how the PrecivityAD® blood test is cost-saving when compared to the current standard approaches for evaluating cognitive impairment in older patients. His data showed a substantial cost savings of $611 per case identified at a 40% adoption rate of testing; this is the first study of economic utility for a blood biomarker used for improving Alzheimer’s disease (AD) diagnosis.
The finding underscores the desirable features of the PrecivityAD blood test in the diagnostic pathway of Alzheimer’s disease: this blood biomarker is accessible, budget-conscious, and comparable in test performance to usual care pathways, said Dr. Monane.
Dr. Joel Braunstein, CEO of C₂N Diagnostics, said, “This year’s CTAD conference was a great success for C₂N Diagnostics and the field as a whole. Many independent researchers and collaborators presented important findings about our Precivity line of blood tests, affirming these clinical tools are aiding healthcare providers in the diagnosis and treatment of Alzheimer’s disease. The tests are also helping researchers address key biological questions about the disease, who is at elevated risk, and how blood tests can help in everyday clinical practice. As the healthcare sector faces continuing cost pressures, we’re also proud that our tests are showing their value in providing clear economic benefits.”
PrecivityAD2™ Blood Test Demonstrated Analytic and Clinical Validity
Tim West, Ph.D., Vice President, Research and Development, C₂N Diagnostics, explained that the PrecivityAD2 test, launched in August 2023 for clinical use as a CLIA LDT, has an overall percent agreement with amyloid PET (positron emission tomography) of 88% using a single test cutoff value as well as diagnostic performance that rivals that of visual read interpretation of amyloid PET for predicting neuropathology.
The test incorporates the Aβ42/40 ratio and p-tau217/np-tau217 ratio (%p-tau217) to produce the Amyloid Probability Score 2 (APS2), a likelihood score that a patient will have brain amyloidosis as defined by a centiloid value greater than 25. Compared to p-tau217 concentration, %p-tau217 is significantly better at detecting brain amyloidosis.
C₂N Biomarker Test Data Shared by Collaborators
At CTAD, Eisai Co., Ltd. presented data using the PrecivityAD blood test that demonstrated rapid change in plasma Aβ42/40 after three months using Leqembi®, an FDA-approved treatment for people with mild cognitive impairment (MCI) or mild dementia due to Alzheimer's disease.
Robert Rissman, Ph.D., Professor of Physiology and Neuroscience and the W.M. Keck Endowed Professor in Medicine at the Keck School of Medicine of University of Southern California, shared findings from the AHEAD 3-45 global prevention study, which is examining whether intervention with lecanemab initiated during the asymptomatic stage can slow biomarker changes and/or new-onset cognitive impairment.
Rissman reported the C₂N Aβ42/40 and %p-tau217 measures showed high predictability for amyloid PET in AHEAD 3-45 study participants when used in conjunction with the AHEAD algorithm or C₂N’s APS2 algorithm. In contrast, p-tau217 and p-tau181 peptides or ratios alone, without the inclusion of AB42/40, demonstrated lower sensitivity and accuracy in detecting amyloid PET-positive participants.
The proposed cut points allow for the detection of participants with >20 centiloids with over 90% accuracy when compared to AB42/40 or the p-tau217 ratio alone. This increased sensitivity can reduce the number of screen failures resulting from negative amyloid PET scans, ultimately lowering the burden and cost for both study sites and participants. The use of plasma prescreening can also enhance the inclusion of diverse groups in the AHEAD study. Findings from this analysis were published on November 6th in the online edition of Alzheimer’s & Dementia.
Suzanne Schindler, M.D., Ph.D., Associate Professor of Neurology, Washington University School of Medicine, gave an overview of the acceptable performance standards for blood biomarkers of Alzheimer's disease in clinical use for symptomatic patients, including the Precivity portfolio of blood tests. She explained research that found a combination of C₂N’s %p-tau217 and Aβ42/40 measures, similar to the APS2 score, accurately classified amyloid status with an AUC of 0.96 as compared to the reference standard of PET biomarkers or cerebrospinal (CSF) biomarkers. The study involved a diverse cohort of 746 older individuals. Dr. Schindler said that race, sex, age, body mass index, and common comorbidities like hypertension and diabetes did not affect the classification of amyloid status by the combination plasma %p-tau217 and Aβ42/40.
Black individuals participating in research studies may have a lower rate of amyloid positivity at baseline, which could decrease the proportion of Black individuals eligible for AD prevention trials and treatment trials for AD dementia, according to research from Chengjie Xiong, Ph.D., Professor of Biostatistics, Washington University School of Medicine. He further detailed that there were no significant racial differences in the longitudinal rates of change for plasma Aβ42/40. These findings, if confirmed by larger and more representative studies across the entire spectrum of social determinants of health, may allow future AD prevention and treatment trials to target a shared efficacy endpoint, according to Xiong.
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.
C₂N Introduced for Research Use Only Test That Can Measure Microtubule Binding Region of Tau (MTBR-tau)
During CTAD, C₂N introduced a much-desired, proprietary biomarker test for Research Use Only (RUO) that can measure the microtubule binding region of tau (MTBR-tau). This analyte measurement was engineered with the intention of uniquely detecting the presence and burden of neurofibrillary “tau” tangles (NFTs) comprised of aggregated tau proteins in the brain and as a potential alternative to invasive, costly, and often inaccessible tau PET tracers.
MTBR-tau is critical for tau protein aggregation and is an enriched core component of NFTs, one of the pathological hallmarks that accumulate in the brain of individuals with Alzheimer’s disease (AD). The MTBR-tau fluid biomarker can be used in the diagnosis of AD, in disease staging, and in the development of tau-directed therapeutics. Furthermore, the MTBR-tau biomarkers have the potential to advance the diagnosis of non-AD tauopathies, such as corticobasal degeneration (CBD), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP).
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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.
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.
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Joni Henderson
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314-464-0009
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