Development of a Blood-based Test for Identifying Synucleinopathy in Patients with Dementia

PROJECT SUMMARY In this Fast Track SBIR application, NeuroDex, Inc. proposes to use its expertise in extracellular vesicle (EV) immunoaffinity isolation to develop a blood test that detects synucleinopathies with high sensitivity, with the long- term goal of helping clinicians identify patients for whom antipsychotic drugs are harmful and contraindicated. Development and commercialization of a sensitive blood test for synucleinopathies would address a major unmet need for selecting appropriate antipsychotic treatments that avoid severe adverse effect. The proposed work leverages a proprietary procedure NeuroDex developed for isolating EVs from plasma using immunoaffinity for cell-specific surface markers. Using this approach, the company demonstrated a > 20-fold increase in signal to noise ratio of NDEs, a degree of specificity that is essential for analyzing aSYN because > 90% of aSYN in plasma does not originate in the brain and is not disease related. Previous efforts to measure aSYN in unprocessed plasma have not yielded any diagnostic value, but measurement after NDE isolation provides powerful classification. Leveraging this approach, NeuroDex has developed assays to test aSYN within and on the surface of neuron-, microglia-, and oligodendrocyte-derived EVs. These assays successfully distinguished 35 healthy controls, 51 PD patients, and 30 MSA patients with high accuracy. NeuroDex now proposes to complete the discovery phase (Phase I) and conduct analytical and clinical validation (Phase II). PHASE I—Aim 1. Identify final biomarkers to be included in the synucleinopathy detection panel. Using 195 samples from healthy individuals and patients with an array of autopsy-confirmed synucleinopathies, we will assess the performance of different panels of the possible biomarkers to select the combination with the best performance. Success Metric: ≥ 80% PPV for identifying patients with synucleinopathies and ≥ 90% NPV. Aim 2. Qualify the selected assays. Success Metrics: precision CoV ≤ 20%, linearity across 8-fold dilution range, and LLQ compatible with clinical samples. Go/No Go Criterion for Progression to Phase II: Completion of the discovery phase to include a defined set of biomarkers in a panel that a) provides ≥ 90% NPV and b) can be measured in a robust manner (variability in precision and reproducibility <20%). PHASE II—Aim 1. Analytical validation of the diagnostic assay. Milestones & Success Metrics: 1) Successful audits for CLIA lab SOP, 2) analytical data package for FDA breakthrough designation submission. Aim 2. Preliminary clinical validation of the diagnostic assay in a CLIA-certified lab. We will validate the assays with 700 samples from patients with dementia with or without synucleinopathies and age-matched controls. Milestones & Success Metrics: primary: NPV ≥ 90%; secondary: PPV ≥ 80%. Impact—Development and rigorous validation of a novel blood test for differential diagnosis of dementia with synuclein pathology would produce a commercially-viable diagnostic to inform appropriate treatment plans and clinical trial stratification for improved drug development.