Quest Diagnostics announced it will offer Roche’s newly FDA-cleared Elecsys® Phospho-Tau (217P) Plasma test, the first and only FDA-cleared single-biomarker blood test able to both rule in and rule out amyloid pathology using validated clinical cutoffs across primary and specialty care settings. Quest plans to launch it as an AD-Detect®-branded service in the fourth quarter of 2026 and fold it into future AD-Detect panels in 2027. Alongside that, the company is launching its own new lab-developed test, AD-Detect ABeta 42/40, p-tau217, and ApoE Evaluation, which combines three Quest Diagnostics to Offer FDA-Cleared Roche pTau217 Blood Test to Assess Alzheimer’s Disease Pathology separate biomarkers into a single multi-marker panel. Michael K. Racke, a board-certified neurologist and Quest’s senior medical director of neurology, framed the moment as a shift already underway in clinical practice: “Blood-based biomarker testing has rapidly set a new standard of care for guiding treatment and diagnosis decisions for Alzheimer’s disease.”
What’s Actually New in These Two Announcements
There are two distinct developments bundled into this news. The first is Roche’s Elecsys pTau217 test itself, which the FDA cleared on August 24, 2026, and which Roche says was validated in individuals 55 and older with signs, symptoms, or complaints of cognitive decline.”The second is Quest’s own multi-biomarker panel, which layers p-tau217 together with amyloid beta 42/40 and APOE genetic risk markers rather than relying on a single marker. Quest says the new test aligns with Alzheimer’s Association guidelines stating that blood-based tests reaching approximately 90% sensitivity and specificity in specialist settings can be used to confirm a diagnosis without further testing, and that the test achieved a 10% indeterminate result rate, notably better than the 15% to 20% indeterminate rate benchmark set by the Global CEO Initiative on Alzheimer’s Disease (CEOi) for a typical clinical population. Amanda Backner, Quest’s executive director and general manager of neurology, tied that improvement directly to combining markers: “Quest’s extensive research demonstrates that blood-based biomarker testing that includes multiple biomarkers may be more sensitive and specific for Alzheimer’s pathology and produces a lower rate of indeterminates compared to the same tests performed individually.”
Why Blood-Based Testing Is Displacing Older Methods
Alzheimer’s diagnosis has traditionally relied on amyloid PET scans or cerebrospinal fluid testing collected via spinal tap, both of which are costly, invasive, and largely limited to specialty centers rather than a typical primary care visit. Published research cited around this announcement has found blood-based biomarker testing to be a more efficient and cost-effective way to assess Alzheimer’s pathology in patients with cognitive decline than amyloid PET scans, which is the underlying case for why a test patients can access through routine bloodwork, at any of Quest’s roughly 2,000 patient service centers nationwide, physician offices, or mobile phlebotomy services with a physician’s order, matters beyond just convenience.
Dan Malarek, President and CEO of Roche Diagnostics North America, called the clearance a milestone: ‘FDA clearance of Elecsys pTau217 marks an important milestone in Alzheimer’s disease diagnosis and underscores Roche’s continued leadership in advancing innovative solutions that can help patients get answers sooner.’
