Quest Diagnostics (NYSE: DGX) announced plans to add the FDA-cleared Roche Elecsys® Phospho-Tau (217P) Plasma (pTau217) blood test to its AD-Detect® portfolio of Alzheimer's disease biomarker tests, according to a company press release.

Roche received FDA clearance for the Elecsys pTau217 test, which the company describes as the first single-assay, single-biomarker blood test cleared to support both rule-in and rule-out assessment of amyloid pathology using validated clinical cutoffs across primary and specialty care settings. Quest plans to offer the test to physicians and clinical trials collaborators nationwide in the fourth quarter of 2026, with plans to incorporate it into AD-Detect panels in 2027.

Separately, Quest announced the launch of a new lab-developed test, AD-Detect® ABeta 42/40, p-tau217, and ApoE Evaluation, available at the end of August. The test combines pTau217, amyloid beta 42/40, and APOE isoform measurements to generate a score predicting the likelihood of Alzheimer's pathology.

Research published in Neurology® Clinical Practice found the new multi-biomarker test achieved an indeterminate rate of 10%, compared to the 15%-20% rate recommended by the Global CEO Initiative on Alzheimer's Disease for a typical clinical population.

"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," said Amanda Backner, executive director and general manager, neurology, Quest Diagnostics.

Both tests will be accessible through Quest's network of approximately 2,000 patient service center locations across the U.S., as well as through physician office and mobile phlebotomy services.