insert therapeutics unidym tego bio sciences science research anti-cancer drugs RNAi therapeutics carbon-based electronics nanotechnology arrowhead pasadena california nasdaq arwr
nanotechnology arrowhead pasadena california nasdaq arwr nanotechnology arrowhead pasadena california nasdaq arwr nanotechnology arrowhead pasadena california nasdaq arwr compound semiconductor materials nano particles laboratory
PRESS RELEASE
August 31, 2006

Arrowhead Subsidiaries Selected to Present at Credit Suisse Nanotechnology Conference

PASADENA, California – August 31, 2006 – Arrowhead Research Corporation (Nasdaq: ARWR), announced today that Dr. Mark Davis, founder and technical consultant to majority-owned subsidiaries Insert Therapeutics and Calando Pharmaceuticals, and John C. Miller, Vice President, Business Development have been selected to present at an invitation only Credit Suisse Nanotech Conference on September 6 and 7, respectively. Dr. Davis' presentation entitled "Nanoparticles for Systemic Medicines and Imaging Agents: Hopes and Realties" will highlight Insert's anti-cancer drug candidate, IT-101, currently being tested in clinical trials, and Calando's nanoparticle technology for the targeted, systemic delivery of RNAi therapeutics. IT-101 is the first nanomedicine designed de novo to reach the clinic.

Dr. Davis is the Warren and Katharine Schlinger Professor of Chemical Engineering at the California Institute of Technology and a member of the Experimental Therapeutics Program of the Comprehensive Cancer Center at the City of Hope. Earlier this year, Dr. Davis was elected to the National Academy of Sciences. Already a member of the National Academy of Engineering, Dr. Davis is one of a few who hold both honors.

Mr. Miller's presentation entitled "Carbon Electronics" will discuss the features and benefits of carbon nanomaterials for electronics applications. Mr. Miller is the primary architect of Arrowhead's strategy of rolling up key intellectual property related to carbon nanotubes. Through its majority-owned subsidiary Unidym, Arrowhead has exclusively licensed key patents and patent applications covering carbon nanotube technologies developed at eight leading universities. Unidym is commercializing new carbon-based electronic products such as conductive, transparent electrodes and thin film transistors.

About Arrowhead Research Corporation

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.

Contacts

Virginia Dadey; Vice President, Investor Relations
Telephone: 212.541.3707
Email: vdadey@arrowres.com