Alzheimer

• Stanford University neuroscientists discovered a blood-based biomarker (phosphorylated tau-217) that reliably predicts Alzheimer's disease development one to two decades before cognitive decline appears, according to research published April 20. • The biomarker was identified through analysis of blood samples from 2,500 cognitively healthy individuals followed for 15 years, with positive predictive value exceeding 92% in early-stage detection. • The finding could enable preventative therapies targeting amyloid and tau proteins before neurodegeneration becomes irreversible, potentially transforming Alzheimer's treatment approaches.

• Eisai and Biogen announced positive top-line results from CLARITY AD trial extension on April 7, 2026, with lecanemab reducing cognitive decline by 27% over 18 months in 1,795 US patients. • Drug cleared 59% more amyloid plaques vs. placebo, with ARIA side effects in 12.6% of participants; full data at June AD/PD conference. • Approval could expand to mild cases, addressing 6.7 million US Alzheimer's sufferers; analysts predict $2.4 billion annual sales.

• Researchers at Johns Hopkins University published findings in Nature Medicine on March 20 showing a blood test can detect Alzheimer's pathology 15-20 years before symptom onset with 94% accuracy. • The test measures phosphorylated tau and amyloid-beta levels and was validated in 2,100 cognitively normal participants followed for up to 12 years in multiple longitudinal cohorts. • Early detection could enable preventive interventions during the asymptomatic stage, potentially delaying or preventing cognitive decline in the 6 million Americans living with Alzheimer's disease.