Availability of C2N’s First Blood-Based Diagnostic Marks Breakthrough in Alzheimer’s Disease
By Rajaneesh K. Gopinath, Ph.D.
On October 29th, Missouri-based C2N Diagnostics announced the clinical availability of PrecivityAD™ blood test, an innovative and highly sensitive blood test that enables the early detection of Alzheimer’s Disease (AD). This announcement marks a breakthrough in the field since AD is hard to diagnose and harder to treat. Approximately 5.8 million people in the US alone are currently living with this age-related, progressive neurodegenerative disorder. Although several drugs are currently in clinical trials, there are no approved treatments yet.
Several years ago, AD diagnosis involved the extensive use of cognitive tests, but that has changed since the advent of imaging techniques such as positron emission tomography (PET), Magnetic resonance imaging (MRI), and Computerized tomography (CT). In some cases, a spinal fluid test is also conducted using the patient’s Cerebrospinal Fluid (CSF) samples.
AD is characterized by several phenotypic outcomes such as aggregation of amyloid-beta (Aβ) peptides that form plaques and the formation of Tau protein-containing neurofibrillary tangles, which ultimately leads to neurodegeneration causing dementia in 80% of all cases. By using tracers that bind to Aβ, the presence of amyloid plaques can be identified through a PET scan (amyloid PET). This imaging tool also helps physicians to diagnose AD patients from other types of dementia accurately. However, these procedures are invasive and unaffordable, making early detection a huge challenge. In contrast, a cost-effective blood-based diagnostic would be ideal for large scale screening.
How Does PrecivityAD™ Work?
Using a mass spectrometry platform, the test precisely measures plasma biomarker concentrations in blood samples collected from the patient’s forearm. Its proprietary Stable Isotope Spike Absolute Quantitation (SISAQ™) methodology quantifies the Amyloid Beta 42/40 ratio (Aβ 42/40) and the presence of Apolipoprotein E (ApoE) isoforms to provides an overall combined score called Amyloid Probability Score (APS). This non-invasive test can only be ordered by a physician and is currently available in 45 states, the District of Columbia, and Puerto Rico. The patient’s blood samples will be sent to C2N’s specialized laboratory located in St. Louis, where they will be processed using a fully automated facility.
“This is really an important advance. You can now walk into your doctor’s office to get a blood test to help detect Alzheimer’s disease,” said Howard Fillit, M.D., Founding Executive Director and Chief Science Officer of the Alzheimer’s Drug Discovery Foundation (ADDF). “This test answers a critical need for less costly and accessible diagnostic testing in memory and dementia care.”
The test by itself cannot diagnose AD but is intended to aid physician evaluations. A low APS (0-36) is consistent with a negative amyloid PET scan result, an intermediate APS (37-57) is inconclusive, requiring further evaluation, but a high APS (58-100) is consistent with a positive amyloid PET scan result.
The test’s clinical arrival is an outcome of data collected from 686 patients older than 60 years of age with subjective cognitive impairment or dementia. In its company webpage, C2N claims that PrecivityAD™ test correctly identified brain amyloid plaque status (as determined by quantitative amyloid PET scans) in 86% of the patients.
Joel B. Braunstein, MD, CEO of C2N, said, “Our mission is to translate exceptional science into unique diagnostics that can help as many people as possible. The PrecivityAD™ blood test introduces a new option for patients, families, and the medical community that has eagerly awaited innovative tools to address Alzheimer’s troubling problems.”
Blood-Based Diagnostics for Alzheimer’s Detection
Early detection is crucial in identifying patients for clinical trials, which eventually helps find a permanent cure for AD. Therefore, in recent years, several research groups have been developing diagnostic tests that would enable large scale screening by identifying blood biomarkers. In July, Eli Lilly announced that its blood test, which measures p-tau217 biomarker, shows promise, and it could be used to improve the differential diagnosis of patients with cognitive impairment.
Similarly, a team of researchers led by Dr. Adam Boxer at the University of California, San Francisco, found that a new ultrasensitive single-molecule array (Simoa) antibody-based approach could differentiate the pTau181 biomarker between healthy and diseased patients. All this pointed out that blood-based tests were on their way to becoming a part of the standard of care. The availability of PrecivityAD™ has now added merit to that prediciton.
Just a month ago, the ADDF granted C2N $2.2 million to advance this very test, bringing its total investment in the company to $2.8 million in the past decade. It is important to note that ADDF provided early seed funding for the development of Amyvid™ PET brain scan, the first FDA-approved diagnostic test for Alzheimer’s disease in 2012.
“Investing in biomarker research has been a core goal for the ADDF because reliable, accessible, and affordable biomarkers for Alzheimer’s diagnosis are critical to our ability to find drugs to prevent, slow, and even cure the disease,” said Dr. Fillit. “Our funding helped bring the first PET scan to market and now has helped bring the first blood test to market.”
Besides this test, C2N’s pipeline also features the APTUS™-Aβ blood test, a highly sensitive method for measuring amyloid-beta peptides in blood samples, and plans for a Brain Health Panel that seeks to detect multiple blood-based markers.
©www.geneonline.com All rights reserved. Collaborate with us: firstname.lastname@example.org