2010-02-08 13:13:18 -

Arrowhead Research Corporation (NASDAQ: ARWR) today announced that it will report its financial results for the fiscal 2010 first quarter ended December 31, 2009, on Thursday, February 11, 2009 at 4:30 p.m. Eastern time (1:30 p.m. Pacific time). To participate in the conference call, please dial 877-941-4774 or 480-629-9760. Investors may also access a live audio webcast of this conference call on the Company's website at www.arrowheadresearch.com : .

A replay of the webcast will be available approximately two hours after the conclusion of the call. The webcast archive will remain available for 90 days. An audio replay will also be available approximately two hours after the conclusion of the call and will be made available until Thursday, February

18, 2010. The audio replay can be accessed by dialing 800-406-7325 or 303-590-3030 and entering passcode 4220149#.

About Arrowhead Research Corporation


Arrowhead Research Corporation ( www.arrowheadresearch.com : ) (NASDAQ: ARWR) is a nanotechnology company commercializing new technologies in the areas of life sciences and electronics. Arrowhead is seeking to build value for shareholders through the progress of its portfolio companies. Currently, Arrowhead is focused primarily on its two majority owned subsidiaries, Unidym, a leader in carbon nanotube technology for electronic applications, and Calando, at the forefront of clinical application of RNAi delivery technology. Arrowhead also has minority investments in two privately held nanobiotech companies.

Investor Relations Contact:The Piacente Group, Inc.Brandi

Floberg212-481-2050 arrowres@tpg-ir.com : mailto:arrowres@tpg-ir.com