The FDA cleared Roche and Eli Lilly’s Elecsys pTau217 blood test to support assessments that can rule in and rule out Alzheimer’s disease in people age 55 and older with signs of cognitive decline. The single-biomarker assay measures phosphorylated tau 217 levels to estimate likelihood of amyloid pathology earlier in the diagnostic pathway. Roche said the test is designed for broad use through integration with Cobas lab instruments and that Labcorp and Quest plan to offer the assay. The approval adds competitive pressure in the rapidly expanding Alzheimer’s diagnostics market as labs pursue scalable blood-based workflows that can reduce reliance on specialty imaging and cerebrospinal fluid testing. For clinicians and payers, the key operational question will be how quickly labs can implement standardized cutoffs and ensure consistency across settings.