Arrowhead Pharmaceuticals Reports Up to 73% Tau Reduction in ARO-MAPT Trial

08:11 AM EDT, 10/14/2026 (MT Newswires) -- Arrowhead Pharmaceuticals (ARWR) reported a mean reduction of up to 73% in cerebrospinal fluid total tau levels at Day 105 in healthy volunteers in an interim phase 1/2a study of its investigational Alzheimer's drug ARO-MAPT, the company said Wednesday. The highest-dose group recorded a maximum individual tau reduction of 85%, with effects sustained 90 days after the final dose, supporting the potential for quarterly or less frequent dosing, the company said. Arrowhead plans to continue studying the drug in patients with early Alzheimer's disease and expects further data updates in 2027, it added. Arrowhead Pharmaceuticals shares were up 5% in premarket activity.