Arrowhead Research Corporation Retains The Piacente Group, Inc. as Strategic Investor Relations Consulting Firm

PASADENA, Calif. - November 17, 2008 - Arrowhead Research Corporation (NASDAQ: ARWR) (“Arrowhead”), a leading nanotechnology company, who, through its majority-owned subsidiaries, commercializes new technologies in the areas of life sciences, electronics and energy, today announced that it has retained The Piacente Group, Inc. (“TPG”), a full service investor relations consulting firm based in New York City. TPG will assist Arrowhead in implementing investor communications and Wall Street outreach programs aimed at making new connections in the financial community for the Company.

"The Piacente Group has a great track record of bringing growth companies like Arrowhead and interested Wall Street investors together," said Christopher Anzalone, President and Chief Executive Officer of Arrowhead. "As we build value for Arrowhead shareholders by way of introducing new products to market via our subsidiaries in the healthcare, electronics and clean energy industries, we look to The Piacente Group to communicate our business strategy and growth initiatives to the right investment audience.”

Brandi Piacente, President of TPG, stated: "We are excited to work with Arrowhead, a leading innovator in the commercialization of nanotechnology-enabled products, as we believe they have a compelling investment story and the qualifications to take a distinctive and leading position in a growing industry. We look forward to partnering with management to implement a strategic and targeted investor relations program that will assist in further enhancing value for shareholders."

Arrowhead Research Corporation (www.arrowheadresearch.com) 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 recent economic slowdown affecting technology companies, the future success of our scientific studies, our ability to successfully develop products, rapid technological change in our markets, changes in demand for our future products, legislative, regulatory and competitive developments and general economic conditions. Our Annual Report on Form 10-K and 10-K/A, recent and forthcoming Quarterly Reports on Form 10-Q and 10-Q/A, recent Current Reports on Forms 8-K and 8-K/A, our Registration Statement on Form S-3, and other SEC filings discuss some of the 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.