Arrowhead Expands Executive Team to Broaden Technical and Operational Expertise

Arrowhead Research Corporation announced today the addition of three executives to its management team: Thomas Haag, Ph.D. J.D. as Chief Patent Officer; Mark Tilley, Ph.D., MBA as Vice President of Advanced Materials; and James Hamilton, M.D., MBA as Vice President of Medical Technologies. These additions are part of an ongoing initiative to better consolidate management of its operating units at the Arrowhead level. "We are honored to have Drs. Tilley, Hamilton, and Haag on our team. They significantly expand our core capabilities and help us better centralize responsibilities at the Arrowhead level,” said Chris Anzalone, Arrowhead’s CEO. "Our model is increasingly capital-efficient and our subsidiaries are better served as Arrowhead enhances its ability to take on larger roles in its companies.” Dr. Tilley joins Arrowhead from DSM N.V.; a $12B Netherlands based specialty performance materials and life science company. Most recently, he served as Senior Investment Manager with DSM’s Corporate Venturing Arm and served on the boards of CreAgri, Novomer, Van Technologies, Harland Medical Systems and InMat. Prior to his work with DSM Ventures, he was Vice President of Research and Business Development for DSM Desotech, an operating division of DSM that is the global market leader in fiber optic coatings and stereo lithographic resins. During his tenure, he led a marketing and technical team and built a flat panel displays materials business that was acquired by JSR in 2005. Dr. Tilley has held marketing and R&D positions at SDC Coatings, a J.V. founded Dow Corning and Pilkington Glass plc, and now currently under the Compass Private Equity Group, and GE Plastics where he started his career at their Corporate R&D center as a Senior Scientist. Mark holds a BS in Chemistry from the University of Manchester Institute of Science and Technology in Manchester, UK, a PhD from North Dakota State University in Fargo, and a MBA from Pepperdine, California. Dr. Haag practiced previously in the Washington D.C. offices of Kenyon & Kenyon LLP and McDermott Will & Emery LLP. He has extensive experience in advising newly formed companies in establishing, developing and leveraging their patent portfolios. Dr. Haag received his B.S. in Biology and Ph.D. in Molecular, Cell & Developmental Biology from UCLA where he was an NIH Predoctoral Fellow in Genetic Mechanisms. He graduated from The George Washington University Law School with honors, receiving the ABA/BNA Award for Excellence in the Study of Intellectual Property Law. He is admitted to practice before the USPTO, in New York and in the District of Columbia. He is registered as California In-House Counsel. Dr. Hamilton graduated Magna cum Laude from Miami University and holds an MD degree from The Ohio State University, with post-graduate specialty training in Emergency Medicine. He is currently a licensed medical practitioner. Dr. Hamilton also completed an MBA at the Fisher College of Business at The Ohio State University. In 2005 he co-founded NanoValent Pharmaceuticals, a nanoparticle vaccine delivery firm. Dr. Hamilton has worked recently as a biotechnology analyst at Reservoir Ventures where he helped delineate a product strategy for several portfolio biotech and medical device companies, and has consulted for biotechnology venture funds. About Arrowhead Research Corporation Arrowhead Research Corporation (www.arrowheadresearch.com) (NASDAQ:ARWR) is a publicly-traded nanotechnology company commercializing new technologies in the areas of life sciences, electronics, and energy. Arrowhead is building value for shareholders through the progress of majority owned subsidiaries founded on nanotechnologies originally developed at universities. The company works closely with universities to source early stage deals and to generate rights to intellectual property covering promising new nanotechnologies. Currently, Arrowhead has four subsidiaries commercializing nanotech products and applications, including anti-cancer drugs, RNAi therapeutics, carbon-based electronics and compound semiconductor materials. Safe Harbor Statement under the Private Securities Litigation Reform Act of 1995: This news release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. These statements are based upon our current expectations and speak only as of the date hereof. Our actual results may differ materially and adversely from those expressed in any forward-looking statements as a result of various factors and uncertainties, including the future success of our clinical studies, our ability to successfully develop and manufacture products, rapid technological change in our industry, changes in demand for our future products, legislative, regulatory and competitive developments and general economic conditions. Our Annual Report on Form 10-K, and other SEC filings discuss these and other important risk factors that may affect our business, results of operations and financial condition. We undertake no obligation to revise or update publicly any forward-looking statements for any reason.