To the Editor The development of novel and effective strategies aimed at modifying the course of Alzheimer disease (AD) is urgently needed. In a recent double-blind randomized clinical trial, Howard and colleagues1 reported that minocycline, a broad-spectrum antibiotic, failed to provide clinical benefits (as assessed by changes in scores of the Mini-Mental State Examination and the Bristol Activities of Daily Living scale) in a cohort of persons with a diagnosis of early AD. The rationale for the investigation of minocycline stems from preclinical evidence supporting the notion that the drug targets critical determinants of AD-like β-amyloid, hyperphosphorylated tau, and microglia activation and neuroinflammation.