Arrowhead Pharmaceuticals, Inc., founded in 1989 and based in Pasadena, California, is a biopharmaceutical company dedicated to discovering and advancing innovative treatments for complex and challenging-to-treat diseases within the United States. The company's extensive therapeutic pipeline primarily leverages RNA interference (RNAi) technology. Among its advanced clinical programs are: ARO-AAT, a Phase II therapeutic targeting liver diseases associated with alpha-1 antitrypsin deficiency; ARO-APOC3, which is undergoing both Phase 2b and Phase 3 clinical evaluations for hypertriglyceridemia; ARO-ANG3, currently in Phase 2b development to reduce the production of angiopoietin-like protein 3; and ARO-HIF2, a Phase 1b candidate designed to treat clear cell renal cell carcinoma. Arrowhead also has several compounds in earlier clinical development, including ARO-HSD in Phase 1/2a for other liver diseases, ARO-ENaC in Phase 1/2a, aimed at decreasing the epithelial sodium channel alpha subunit in lung airways, and ARO-C3, also in Phase 1/2a, for complement-mediated diseases. Further expanding its diverse portfolio, the company is actively developing ARO-Lung2 for chronic obstructive pulmonary disorder (COPD), ARO-DUX4 for facioscapulohumeral muscular dystrophy, ARO-XDH for uncontrolled gout, and ARO-COV for COVID-19 and other pulmonary-borne pathogens. Beyond its core internal programs, Arrowhead is involved in the progression of JNJ-3989, a subcutaneously administered RNAi therapeutic for chronic hepatitis B virus infection; Olpasiran, intended to reduce apolipoprotein A production; and ARO-AMG1, which targets genetically validated cardiovascular pathways. Strategic collaborations are integral to Arrowhead's development efforts. The company holds a licensing and research agreement with Janssen Pharmaceuticals, Inc. for the co-development of ARO-JNJ1, ARO-JNJ2, and ARO-JNJ3, all RNAi therapeutics focused on liver-expressed targets. Additionally, Arrowhead has a licensing and research partnership with Takeda Pharmaceuticals U.S.A., Inc. to develop an RNAi therapeutic candidate specifically for liver disease.