Next Generation Blood Test Aims to Establish New Standard in Alzheimer’s Disease Diagnosis with Combined Measures of Amyloid Beta and Tau Protein
The test uses precise and robust mass spectrometry-based measurements of two key plasma proteins implicated in the AD process: tau and amyloid beta. (Credit: CDC on Unsplash)
C₂N Diagnostics, LLC, a leader in advanced brain health diagnostics, today announced at the Clinical Trials on Alzheimer’s Disease (CTAD) 2022 EU/US Task Force on Blood Biomarkers its next generation test to aid in the diagnosis of Alzheimer’s disease (AD): the PrecivityAD2 blood test. With an anticipated launch in Q1 2023, the test is expected to facilitate earlier and more accurate diagnosis of AD pathology. The test uses precise and robust mass spectrometry-based measurements of two key plasma proteins implicated in the AD process: tau and amyloid beta.
The tau protein measured in the PrecivityAD2 blood test is expressed as a concentration ratio between two peptides that contain tau amino acid 217 known as the p-tau217 Ratio; one peptide is phosphorylated at tau217, the second is not phosphorylated at tau217 (p-tau217/np-tau217). Based on early clinical studies, including one study in a difficult-to-diagnose, real-world population of patients with cognitive impairment or dementia, combining the quantitation of this p-tau217 Ratio with C₂N’s amyloid beta 42/40 Ratio (Aβ42/40) appears to achieve comparable levels of diagnostic performance as the current clinical gold standards of amyloid PET imaging and cerebrospinal fluid tests.
The PrecivityAD2 test uses a statistical algorithm to integrate a patient’s Aβ42/40 Ratio and p-Tau217 Ratio to calculate the Amyloid Probability Score 2 (APS2). The APS2 determines whether a patient is positive or negative for brain amyloid plaques based on a binary cutoff value. Multiple advantages exist for symptomatic patients to receive an early and accurate diagnosis of Alzheimer’s disease; details are available at Benefits of an Early Diagnosis.
The PrecivityAD2 blood test is a significant innovation in the field of Alzheimer’s diagnostics. This is particularly relevant at a time when Alzheimer’s disease-modifying anti-amyloid therapies are on the horizon and may be available in the future for some patients. Existing diagnostic tools have notable limitations: amyloid PET imaging is costly, remains a difficult procedure to access, and exposes individuals to radiation while cerebrospinal fluid biomarkers require a spinal tap.
Dr. Joel Braunstein, C₂N president and CEO, said, “Our existing test, the PrecivityAD blood test, relies on specific measures of plasma Aβ42/40 and detection of the Apolipoprotein E proteotype (equivalent to ApoE genotype), using our proprietary mass spectrometry platform. The PrecivityAD2 test is our next-generation blood test, a natural extension of our prior two years of clinical experience with the PrecivityAD test. With the PrecivityAD2 blood test, we believe clinicians in most cases will have the option to avoid the need for additional CSF or amyloid PET imaging to help promptly rule in or rule out the presence of amyloid plaques for their patients with cognitive impairment. This could accelerate time to diagnosis and proper treatment for many patients, enhance patient access and convenience, and reduce costs by eliminating more complex and costly amyloid detection tests.
“The foundation for this transformative diagnostic technology was conceived by C₂N’s collaborators at Washington University School of Medicine. It was optimized and validated by C₂N scientists and neurobiologists, and generously supported by GHR Foundation, Alzheimer’s Drug Discovery Foundation, National Institute on Aging, Alzheimer’s Association, and BrightFocus Foundation. Finally, none of these advances would have been made possible without the altruism of many clinical trial participants. C₂N looks forward to sharing additional clinical data and details of the upcoming commercial launch of the PrecivityAD2™ blood test as a validated laboratory developed test from our CLIA-certified and CAP-accredited laboratory in early 2023.”
“The global healthcare system must do more to improve the accurate diagnosis of patients experiencing cognitive signs or symptoms. Our own research shows that early misdiagnosis rates are unacceptably high and can be improved with high-quality diagnostic tests,” stated Oskar Hannson, MD, PhD, full Professor in Neurology at Lund University, Senior Consultant in Neurology at Skåne University Hospital in Sweden, and C₂N collaborator. “I am looking forward to working with C₂N in the years ahead to build the necessary evidence to demonstrate that blood-based biomarkers like the PrecivityAD2 test can make a meaningful difference in patients’ lives and improve the ways in which clinicians provide care.”
Source: Company Press Release