Arrowhead Announces Interim Results From Ongoing Phase 1/2a Study Of ARO-MAPT, Investigational RNAi Therapeutic Being Developed As Potential Treatment For Alzheimer’s Disease And Other Tauopathies

• Arrowhead’s TRiM™ platform achieves clinical validation for delivery of siRNA that crosses the blood-brain barrier after subcutaneous injection
• ARO-MAPT demonstrates mean cerebrospinal fluid total tau reduction of 73% on Day 105, with a maximum individual reduction of 85%, supporting the potential for quarterly dosing
• Arrowhead will host a webinar today, October 14, at 2:30 PM ET/11:30 am PT to review additional interim results

Arrowhead Pharmaceuticals, Inc. (NASDAQ:ARWR) today announced interim results from an ongoing Phase 1/2a study of ARO-MAPT, the company’s investigational RNA interference (RNAi) therapeutic being developed as a potential treatment for Alzheimer’s disease and other tauopathies. These results represent the first successful clinical validation of a platform to deliver siRNA across the blood-brain barrier and achieve substantial target gene knockdown in the brain. In healthy volunteers, subcutaneous administration of ARO-MAPT achieved deep and durable reductions in cerebrospinal fluid (CSF) total tau, with a mean reduction of up to 73% at Day 105 and a maximum reduction of 85%.

Arrowhead will review additional results during its webinar today at 2:30 pm ET/11:30 a.m. PT, featuring presentations from Arrowhead management and Adam Boxer, M.D., Ph.D., Endowed Professor in Memory and Aging in the Department of Neurology at the University of California, San Francisco. A live webcast with Q&A and replay will be available on the Events and Presentations page under the Investors section of the Arrowhead website.