Quest Diagnostics to Offer FDA-Cleared Alzheimer's Blood Test, Expanding Diagnostic Options

Quest Diagnostics has announced plans to offer laboratory testing based on Fujirebio Diagnostics' recently FDA-authorized Alzheimer's disease blood test. This move signifies a significant advancement in the accessibility and scalability of Alzheimer's diagnostics, potentially revolutionizing the way the disease is detected and managed.

Fujirebio's Groundbreaking Blood Test

In May, Fujirebio's in vitro diagnostic became the first blood test to aid in the diagnosis of Alzheimer's cleared by the FDA. The Lumipulse G pTau 217/β-Amyloid 1-42 Plasma Ratio test compares the ratio of two proteins, pTau217 and beta-amyloid 1-42, to help identify patients with amyloid pathology associated with Alzheimer's.

Fujirebio validated the test in a study of 499 people, achieving impressive results:

• Positive predictive value: 92%
• Negative predictive value: 97%
• Less than 20% of people received indeterminate results

These figures surpass the performance of Quest's previously launched laboratory-developed test (LDT) for similar biomarkers.

Quest's Strategic Move and Market Implications

Quest Diagnostics plans to make Fujirebio's test available for use by physicians and researchers this summer. This addition complements Quest's existing portfolio, which includes an LDT for beta-amyloid 42/40 and pTau217 launched in April.

Quest CEO Jim Davis discussed the potential impact of these blood tests at a recent William Blair event:

"It over time will largely replace PET-CT as the primary diagnostic tool for the detection of Alzheimer's," Davis stated. He added that testing for a combination of beta-amyloid and tau biomarkers could "give clinicians an earlier view of early onset Alzheimer's long before you would see it in a PET-CT."

The introduction of these blood tests is particularly timely, as new medicines are being developed that are most effective in the early stages of Alzheimer's disease.

Implications for Primary Care and Neurology

The availability of blood tests for Alzheimer's biomarkers could significantly impact the patient care pathway. Davis emphasized the potential benefits for primary care physicians:

"Primary care physicians are using this test to determine should a patient get referred to a neurologist or not. And the number one problem with Alzheimer's disease today is getting a referral into a neurologist," he explained. "If a primary care physician can run a test to determine who really needs to get referred and who doesn't, it will be a huge help to the overall health system."

This development may streamline the diagnostic process, potentially leading to earlier interventions and more efficient use of specialist resources.