UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): October 21, 2008

Arrowhead Research Corporation

(Exact name of registrant as specified in its charter)

0-21898

(Commission File Number)

Delaware	46-0408024
(State or other jurisdiction of incorporation)	(IRS Employer Identification No.)

201 South Lake Avenue, Suite 703, Pasadena, CA 91101

(Address of principal executive offices) (Zip Code)

Registrant’s telephone number, including area code (626) 304-3400

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)

¨ Pre-commencement communications pursuant to Rule 13e-4 (c) under the Exchange Act (17 CFR 240.13e-4(c)

Item 8.01. Other Events.

On October 21, 2008, Arrowhead Research Corporation (the “Company”) issued a new release in which the Chief Executive Officer of the Company updated stockholders on the Company’s majority owned subsidiary, Calando Pharmaceuticals, Inc. The release is one of several planned weekly updates. A copy of the news release is attached as Exhibit 99.1 to this Form 8-K.

Item 9.01. Financial Statements and Exhibits.

(c) Exhibits.

Exhibit No.	Description
99.1	News Release dated October 21, 2008

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

Date: October 27, 2008

ARROWHEAD RESEARCH CORPORATION
By:	/s/ Paul C. McDonnel
	Paul C. McDonnel
	Chief Financial Officer