Journal Article

Early Clinical Utility Data of a Blood Biomarker Test in the Evaluation of Mild Cognitive Impairment

Holtzman, David, Fogelman, Ilana, Monane, Mark, West, Tim, Braunstein, Joel, Snider, Joy, Drake, Jonathan, Bateman, Randall

2021

Overview

Abstract There is an important unmet need for timely, noninvasive, low-burden evaluation of patients presenting with mild cognitive impairment (MCI). The PrecivityAD™ blood test quantifies plasma concentrations of amyloid-β 42 and 40 and apolipoprotein E-specific peptides that are combined with age in an algorithm to identify the likelihood of amyloid plaques in the brain as measured by amyloid PET scans. This test has previously demonstrated 92% sensitivity and 77% specificity. The study objective was to evaluate the clinical utility of the test and the Amyloid Probability Score (APS), the test output value. Eighteen patients (median age 72, 55% male, 88% white) with MCI received the PrecivityAD blood-based biomarker test. The mean APS was 31 (range 0-91): 13 patients had low scores (APS 0-35), 2 had high scores (58-100) and 3 had intermediate (inconclusive) scores (APS 36-57). The mean probability of Alzheimer's disease (AD) diagnosis was rated by clinicians as 63% (range 25-80) pre-test and 31% post-test (range 5-95) (p < 0.0005). AD probability rated by clinicians was decreased in 12/13 low APS patients and increased in 2/2 high APS patients. Donepezil was discontinued in 5/8 low APS patients on therapy and initiated in 1/1 high APS patients not on therapy, representing a change in treatment management in 33% (6/18) of study patients. In summary, this blood-based biomarker test showed clinical utility in its association with physician decision-making around diagnostic certainty and drug therapy management in MCI patients.

• Publisher: Oxford University Press
• Subject: Biomarkers / Cognitive ability / Mild cognitive impairment