PASADENA, Calif.--(BUSINESS WIRE)---- $arwr--Arrowhead Pharmaceuticals, Inc. (NASDAQ: ARWR) today announced that it has filed a request for regulatory clearance to initiate a Phase 1/2a clinical trial of ARO-MAPT, the company's investigational RNA interference (RNAi) therapeutic being developed as a potential treatment for tauopathies including Alzheimer's disease, a progressive neurodegenerative disease characterized by cognitive and functional decline. Alzheimer's disease is the most common cause of de. ...