PASADENA, Calif.–(BUSINESS WIRE)– Arrowhead Research Corporation (NASDAQ: ARWR), a biopharmaceutical company developing targeted RNAi therapeutics, today announced that it has initiated dosing in a Phase 1 clinical trial of ARC-AAT, the company’s candidate for the treatment of liver disease associated with Alpha-1 Antitrypsin Deficiency (AATD), a rare genetic disorder that severely damages the liver and lungs of affected individuals. Trial initiation followed successful completion of the Clinical Trial Notification (CTN) regulatory process in Australia. The study will be conducted in two parts, with Part A in healthy volunteers and Part B in patients with AATD. The primary objectives of the study are to determine the safety and tolerability of escalating doses of ARC-AAT, evaluate the pharmacokinetics, and determine the effect on circulating levels of alpha-1 antitrypsin. Initial data from this study is expected in late 2015.