Dive Brief:
- Quest Diagnostics is planning to offer laboratory testing based on Fujirebio Diagnostics’ recently Food and Drug Administration-authorized Alzheimer’s disease 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. Quest, which disclosed its plans for the IVD last week, launched a laboratory-developed test for similar biomarkers in April.
- The clinical lab plans to make Fujirebio’s Lumipulse G pTau 217/β-Amyloid 1-42 Plasma Ratio test available for use by physicians and researchers this summer.
Dive Insight:
Fujirebio’s IVD compares the ratio of two proteins, pTau217 and beta-amyloid 1-42, to help identify patients with amyloid pathology associated with Alzheimer’s. Cerebrospinal fluid tests that analyze the same biomarkers are an established part of the toolkit for assessing patients with cognitive impairment. However, the tests need samples that are collected via lumbar puncture.
Blood tests could be more accessible and scalable than CSF diagnostics. The advantages have spurred interest in using blood tests to identify patients who should have a PET scan to check for amyloid plaques in the brain. Ultimately, blood tests could eliminate the need for PET scans in some patients.
Quest has been working toward that goal, launching LDTs and now positioning itself to start providing Fujirebio’s FDA-cleared diagnostic. Fujirebio validated the test in a study of 499 people, linking the IVD to positive and negative predictive values of 92% and 97%, respectively. Less than 20% of people received indeterminate results.
The predictive values are higher than those Quest reported for its beta-amyloid 42/40 and pTau217 LDT in April. Quest CEO Jim Davis discussed the company’s test at a William Blair event in June, telling attendees that “it over time will largely replace PET-CT as the primary diagnostic tool for the detection of Alzheimer’s.”
Davis said 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 value of early diagnosis is increasing as companies develop medicines that are most effective in people in the early stages of the disease. Davis said uptake of Quest’s LDT was “really starting to take off.”
“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,” Davis said. “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.”
