Editorial: Real-World Outcomes of Disease-Modifying Therapies Highlight the Need for Diagnostic Biomarkers in Early Alzheimer's Disease.

The promise of targeted humanized monoclonal antibody therapies to amyloid ß and tau protein in Alzheimer's disease from clinical trial data has not been realized when put to the test in real-world studies and practice. There have been regulatory approvals for diagnostic blood tests in China, Japan (HISCL Aß42/40), and the United Kingdom (UK) (PrecivityAD2). On May 16, 2025, the US FDA approved the Lumipulse G blood test, which utilizes the plasma pTau217/Aß1-42 ratio, for the diagnosis of cerebral amyloid plaques in symptomatic patients of 55 years or more. Biological biomarkers and targets are currently being evaluated in phase 1 to phase 3 clinical trials, to rapidly implement less invasive blood-based assays to detect tau species and neurofilament light (NfL). However, clinical validation of the diagnostic value of identifying blood biomarkers still requires support from amyloid positron emission tomography (PET) brain scans and/or the results of cerebrospinal fluid (CSF) analysis. This editorial aims to identify how real-world outcomes of new disease-modifying therapies highlight the need for diagnostic biomarkers for early Alzheimer's disease and the current status of biomarkers identified by blood plasma, CSF, and imaging.