C2N’s PrecivityAD2 blood test improves Alzheimer’s diagnosis and clinical decision-making, study finds

A new study has demonstrated that healthcare providers who used the PrecivityAD2 blood biomarker test, developed by C2N Diagnostics, significantly improved their ability to assess the probability of Alzheimer’s disease (AD) in patients. The findings, published in Diagnostics, reveal that the PrecivityAD2 test enhances diagnostic confidence, refines treatment strategies, and minimises unnecessary testing.

By measuring amyloid plaques in the brain, a well-established pathological marker of Alzheimer’s disease, the PrecivityAD2 test provides clinicians with an objective Amyloid Probability Score 2 (APS2). This enables better decision-making regarding Alzheimer’s medications, disease-modifying therapies, and the need for further neurological assessments.

According to the research, clinicians who incorporated the PrecivityAD2 blood test into their diagnostic workflow reported increased certainty in determining whether a patient’s cognitive impairment was due to Alzheimer’s. The results of the study suggest that this blood biomarker test could play a pivotal role in improving early detection and guiding treatment decisions for patients suspected of having Alzheimer’s disease.

What Does the Study Reveal About the PrecivityAD2 Test’s Clinical Utility?

The study, Clinical Utility of an Alzheimer’s Disease Blood Test Among Cognitively Impaired Patients: Results from the Quality Improvement PrecivityAD2 (QUIP II) Clinician Survey Study, involved 203 patients across eight clinical sites, including a diverse cohort of Black, Hispanic, and Asian minority groups. The research found that clinicians’ confidence in diagnosing Alzheimer’s increased from 50–60% to over 90% for patients with a positive APS2 result, enabling more precise treatment recommendations. Patients who received a positive APS2 result—suggesting an increased likelihood of amyloid plaque accumulation—were 35% more likely to be prescribed Alzheimer’s medication, including disease-modifying therapies such as lecanemab. Conversely, patients with a negative APS2 result, indicating a lower probability of Alzheimer’s, saw a 70% decrease in unnecessary AD medication prescriptions and additional brain amyloid testing.

Dr. Robert M. Carlile, a study investigator based at Palmetto Primary Care Physicians, underscored the significance of these findings, stating that the PrecivityAD2 test has simplified the diagnostic process for patients experiencing cognitive decline. He noted that the test has been straightforward to integrate into clinical practice, leading to meaningful changes in decision-making around Alzheimer’s disease diagnostic certainty, medication management, and additional brain amyloid testing.

How Does the PrecivityAD2 Test Compare to Traditional Alzheimer’s Diagnostics?

Historically, diagnosing Alzheimer’s disease has relied on cerebrospinal fluid (CSF) analysis or amyloid PET imaging, both of which are invasive, expensive, and not widely accessible. The PrecivityAD2 test, in contrast, offers a non-invasive, cost-effective alternative that provides clinically actionable results without requiring lumbar punctures or expensive neuroimaging.

Dr. Joel Braunstein, CEO of C2N Diagnostics, highlighted the transformative potential of biomarker-based testing for Alzheimer’s. He explained that too often, patients experience a delayed and complex diagnostic journey when faced with new cognitive concerns. The PrecivityAD2 blood test, he said, has the potential to bring much-needed clarity, improve healthcare quality, and shorten the time to an accurate diagnosis.

The study builds upon prior research, including a 2024 study published in the Journal of the American Medical Association (JAMA), which confirmed that APS2 results significantly improved the accuracy of Alzheimer’s diagnoses in primary care settings. The QUIP II findings reinforce data from the original QUIP I study, which assessed the PrecivityAD blood test in real-world clinical settings.

How Is C2N Expanding Access to the PrecivityAD2 Test?

To broaden global access to blood-based Alzheimer’s diagnostics, C2N Diagnostics has partnered with leading clinical laboratories worldwide. These collaborations ensure that the PrecivityAD2 test is available to a wider patient population, particularly in underserved regions where traditional Alzheimer’s testing may not be accessible. C2N has established agreements with Unilabs in Europe, Grupo Fleury in Brazil, Healius Pathology in Australia, and Mediford Corporation in Japan for research purposes. In the U.S., C2N has entered a non-exclusive agreement with Mayo Clinic Laboratories, further expanding the reach of its Alzheimer’s biomarker testing.

The PrecivityAD2 and PrecivityAD tests are currently available in 49 U.S. states, the District of Columbia, and Puerto Rico, with New York pending certification.

What Does the Future Hold for Blood Biomarker Testing in Alzheimer’s Care?

The growing adoption of blood biomarker tests like PrecivityAD2 represents a paradigm shift in Alzheimer’s diagnostics. With over 30,000 Precivity-related biomarker measures published in peer-reviewed literature, and ongoing research exploring the role of plasma biomarkers in neurodegeneration, experts predict that non-invasive Alzheimer’s testing will become a standard component of memory care assessments.

The findings from the QUIP II study suggest that PrecivityAD2 could be a game-changer, not only for early Alzheimer’s detection but also for optimising treatment plans and improving patient outcomes. As the healthcare industry continues to prioritise accessible, high-performance diagnostic tools, C2N’s PrecivityAD2 test is positioned to become an essential resource for neurologists, geriatricians, and primary care physicians worldwide.