FDA Clears PrecivityAD2: A Breakthrough Blood Test for Alzheimerโs Disease Diagnosis
The U.S. Food and Drug Administration (FDA) has granted clearance for PrecivityAD2, a single blood test designed to assist healthcare professionals in ruling in or ruling out an Alzheimerโs disease diagnosis. Developed by C2N Diagnostics, PrecivityAD2 marks a significant regulatory milestone as the first Alzheimerโs blood test cleared by the FDA for symptomatic adults aged 40 years and older.
Highlighting the clinical impact of the clearance, Joel Braunstein, MD, MBA, CEO and president of C2N, stated in a press release:
โWe believe the PrecivityAD2 test will play a vital health system role in the years ahead to help streamline and simplify the complex diagnostic pathway that many patients face when dealing with serious memory concerns.โ
Mechanism of Action and Clinical Application
PrecivityAD2 operates by utilizing high-resolution mass spectrometry to detect and quantify key pathological proteins associated with Alzheimerโs disease. Specifically, the test measures beta-amyloid and tau peptide isoforms in the blood stream. These measurements are expressed as ratios and processed through a proprietary statistical algorithm to calculate the numerical likelihood of underlying brain amyloid pathology.
The test is intended to be implemented as an adjunct tool alongside a comprehensive clinical assessment rather than as a standalone diagnostic instrument.
Clinical Validation and Accuracy Metrics
Prior to FDA clearance, clinical validation data were gathered from a study evaluating 1,142 adults presenting with signs or symptoms of cognitive decline. Furthermore, independent research conducted by the Clinical Memory Research Unit at Lund University in Sweden and published in npj Dementia demonstrated high diagnostic precision across both primary care settings and specialized memory clinics.
PrecivityAD2 Performance and Validation Data
| Validation Parameter | Statistical Value | Clinical Interpretation |
| Positive Predictive Value (PPV) | 97.6% | High reliability for a positive result in clinical evaluation |
| Negative Predictive Value (NPV) | 93.1% | High reliability for ruling out amyloid pathology |
| Overall Diagnostic Accuracy | 91.0% | Established via npj Dementia published findings |
| Sensitivity | 90.0% | Accuracy in identifying true positive cases |
| Specificity | 92.0% | Accuracy in identifying true negative cases |
| Target Population | Symptomatic adults $\ge 40$ years | Broad demographic applicability for early cognitive decline |
Broader Implications for Clinical Trials and Research
The regulatory clearance of PrecivityAD2 underscores an expanding momentum behind blood-based biomarker diagnostics. According to Laura Nisenbaum, PhD, interim chief science officer with the Alzheimerโs Drug Discovery Foundationโan organization that invested in C2Nโs foundational research:
โTests like this donโt just help to diagnose Alzheimerโs. They can also identify the right patients for a clinical trial and confirm whether a drug is engaging its target.โ
Dr. Nisenbaum further emphasized how modern biomarker precision is transforming research methodologies, noting that 83% of active Alzheimerโs trials currently incorporate a biomarker component.
The FDA-cleared version of PrecivityAD2 is anticipated to become available for routine clinical utility later in 2026.
Zero-CLS Interactive Widget Code (WordPress / Soledad Theme)
To embed an interactive test metrics explorer on a WordPress site utilizing the Soledad theme without triggering Cumulative Layout Shift (CLS), the following production-ready HTML, CSS, and JavaScript code utilizes strict container bounding and fixed viewport constraints:
HTML
<!-- Zero-CLS PrecivityAD2 Interactive Metric Explorer -->
<div class="alz-widget-wrapper">
<div class="alz-header">
<h3>PrecivityAD2 Clinical Performance Explorer</h3>
<p>Select a validation category to review specific diagnostic metrics.</p>
</div>
<div class="alz-tab-bar">
<button class="alz-btn active" onclick="switchAlzTab('predictive')">Predictive Values</button>
<button class="alz-btn" onclick="switchAlzTab('accuracy')">Diagnostic Accuracy</button>
<button class="alz-btn" onclick="switchAlzTab('utility')">Clinical Utility</button>
</div>
<div class="alz-viewport-box">
<div id="alz-pane-predictive" class="alz-content-pane active">
<h4>Predictive Value Metrics</h4>
<p>Demonstrated a 97.6% positive predictive value (PPV) and a 93.1% negative predictive value (NPV) in a validation cohort of 1,142 symptomatic adults.</p>
</div>
<div id="alz-pane-accuracy" class="alz-content-pane">
<h4>Accuracy, Sensitivity & Specificity</h4>
<p>Published research in npj Dementia showed 91% overall accuracy, 90% sensitivity, and 92% specificity for detecting brain amyloid pathology.</p>
</div>
<div id="alz-pane-utility" class="alz-content-pane">
<h4>Trial Integration & Access</h4>
<p>Streamlines diagnostic pathways for adults aged 40 and older, while supporting modern trial designs where 83% of active trials utilize biomarkers.</p>
</div>
</div>
</div>
<style>
/* Strict structural bounding prevents Cumulative Layout Shift (CLS) */
.alz-widget-wrapper {
width: 100%;
max-width: 800px;
background: #fbfbfc;
border: 1px solid #dcdfe6;
border-radius: 6px;
padding: 20px;
box-sizing: border-box;
margin: 25px auto;
font-family: inherit;
}
.alz-header h3 {
margin: 0 0 4px 0;
font-size: 1.2rem;
color: #1a1a1a;
}
.alz-header p {
margin: 0 0 14px 0;
font-size: 0.85rem;
color: #555;
}
.alz-tab-bar {
display: flex;
gap: 8px;
margin-bottom: 12px;
flex-wrap: wrap;
}
.alz-btn {
background: #eef2f7;
border: none;
padding: 8px 14px;
border-radius: 4px;
cursor: pointer;
font-weight: 600;
font-size: 0.8rem;
color: #333;
transition: background 0.2s;
}
.alz-btn.active {
background: #004080;
color: #fff;
}
/* Fixed viewport height constraints eliminate layout jumps */
.alz-viewport-box {
position: relative;
min-height: 110px;
background: #ffffff;
border: 1px solid #e1e4e8;
border-radius: 4px;
padding: 15px;
box-sizing: border-box;
}
.alz-content-pane {
display: none;
position: absolute;
top: 15px;
left: 15px;
right: 15px;
bottom: 15px;
}
.alz-content-pane.active {
display: block;
}
.alz-content-pane h4 {
margin: 0 0 6px 0;
font-size: 1rem;
color: #004080;
}
.alz-content-pane p {
margin: 0;
font-size: 0.9rem;
color: #444;
line-height: 1.4;
}
</style>
<script>
function switchAlzTab(paneId) {
var panes = document.querySelectorAll('.alz-content-pane');
var buttons = document.querySelectorAll('.alz-btn');
panes.forEach(function(p) {
p.classList.remove('active');
});
buttons.forEach(function(b) {
b.classList.remove('active');
});
document.getElementById('alz-pane-' + paneId).classList.add('active');
event.currentTarget.classList.add('active');
}
</script>
Zero-CLS Clinical Trials Summary HTML Code
The standalone summary card below highlights key metrics regarding the validation trial. Engineered with rigid CSS box-sizing constraints, it guarantees zero layout shifting upon page rendering.
HTML
<div class="clinical-summary-card-alz">
<div class="cs-badge">Validation Trial Summary</div>
<h4 class="cs-title">PrecivityAD2 Diagnostic Validation Metrics</h4>
<p class="cs-desc"><strong>Core Impact:</strong> FDA clearance establishes PrecivityAD2 as the first blood test for symptomatic adults aged 40+, backed by robust multi-center validation data.</p>
<div class="cs-metrics-grid">
<div class="cs-metric-box">
<span class="cs-val">97.6%</span>
<span class="cs-label">Positive Predictive Value (PPV)</span>
</div>
<div class="cs-metric-box">
<span class="cs-val">93.1%</span>
<span class="cs-label">Negative Predictive Value (NPV)</span>
</div>
<div class="cs-metric-box">
<span class="cs-val">1,142</span>
<span class="cs-label">Patients Evaluated in Validation Cohort</span>
</div>
</div>
</div>
<style>
.clinical-summary-card-alz {
width: 100%;
max-width: 800px;
background: #ffffff;
border-left: 4px solid #004080;
border-top: 1px solid #dcdfe6;
border-right: 1px solid #dcdfe6;
border-bottom: 1px solid #dcdfe6;
border-radius: 4px;
padding: 20px;
box-sizing: border-box;
margin: 25px auto;
font-family: inherit;
}
.cs-badge {
display: inline-block;
background: #e6eff7;
color: #004080;
font-size: 0.75rem;
font-weight: 700;
padding: 3px 7px;
border-radius: 3px;
text-transform: uppercase;
margin-bottom: 6px;
}
.cs-title {
margin: 0 0 6px 0;
font-size: 1.1rem;
color: #1a1a1a;
}
.cs-desc {
margin: 0 0 15px 0;
font-size: 0.85rem;
color: #555;
line-height: 1.4;
}
.cs-metrics-grid {
display: flex;
gap: 10px;
flex-wrap: wrap;
}
.cs-metric-box {
flex: 1;
min-width: 130px;
background: #f9fbfd;
border: 1px solid #eaeaea;
border-radius: 4px;
padding: 10px;
box-sizing: border-box;
text-align: center;
}
.cs-val {
display: block;
font-size: 1.3rem;
font-weight: 700;
color: #004080;
margin-bottom: 3px;
}
.cs-label {
display: block;
font-size: 0.75rem;
color: #666;
line-height: 1.2;
}
</style>