Washington, D.C. 20549



Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): June 2, 2006

Arrowhead Research Corporation

(Exact name of registrant as specified in its charter)


Delaware   0-21898   46-0408024

(State or other jurisdiction

of incorporation)



File Number)


(I.R.S. Employer

Identification No.)

201 South Lake Avenue, Pasadena, CA 91101

(Address of principal executive offices) (Zip Code)

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

Not Applicable

(Former name or former address, if changed since last report)

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 5.02 Departure of Directors or Principal Officers; Election of Directors; Appointment of Principal Officers.

On June 2, 2006, by mutual agreement, Leon Ekchian stepped down from his position as President and Director of the Company.

By action of the Board of Directors, Joseph T. Kingsley has been appointed Interim President as of the same date. Mr. Kingsley has been the Chief Financial Officer of Arrowhead since September 2004. Mr. Kingsley has more than 25 years of executive-level, operational and financial management experience in the biotech, commercial, international, and defense-related industries. Prior to joining the Company, from January 2002 to September 2004, he was Chief Financial Officer for Eidogen, Inc., a Pasadena-based company developing computational drug discovery platforms. From March 1997 to January 2002, Mr. Kingsley was Vice President Operations and Chief Financial Officer for Paracel, an integrated turnkey computer systems provider for the life sciences community that was acquired by Celera Genomics (AMEX:CRA) in June 2000. Mr. Kingsley held similar positions with Pico Products, Inc. a publicly held cable TV product supplier, Kaiser Marquardt, Inc., and Science Applications International Corp. (SAIC), a Fortune 500 government and commercial contractor. Mr. Kingsley is a CPA. He received his B.A. in Economics from Ohio Wesleyan University, and his MBA from Northwestern University.


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 hereunto duly authorized.

Date: June 8, 2006





/s/ Joseph T. Kingsley


Joseph T. Kingsley, Chief Financial Officer