Form 8-K



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): May 4, 2005



Arrowhead Research Corporation

(Exact name of registrant as specified in its charter)



Delaware   0-21898   46-0408024

(State or other jurisdiction

of incorporation)

  (Commission File Number)  

(I.R.S. Employer

Identification No.)


1118 East Green Street, Pasadena, CA   91106
(Address of principal executive offices)   (Zip Code)


Registrant’s telephone number, including area code: (626) 792-5549


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 (see General Instruction A.2. below):


¨ 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 May 4, 2005, Arrowhead Research Corporation (the “Company”) announced that it will redeem its outstanding warrants to purchase common stock (the “Warrants”) on June 15, 2005. The Warrants have an exercise price of $1.50 per share and are subject to redemption pursuant to their terms at the redemption price of $0.001 per share. The Company has fixed the “Exercise Deadline” at 4:00 P.M. PT on June 14, 2005. Unless the Exercise Deadline is extended, Warrants not properly exercised by the Exercise Deadline will be redeemed by the Company. Payment of the redemption price will be made by the Company promptly upon presentation and surrender of the warrant certificate.


The Company’s press release announcing the Company’s Warrant Redemption is attached as Exhibit 99.1 to this report.


Item 9.01. Financial Statements and Exhibits.


  (c) Exhibits.


Exhibit No.



99.1   Press Release announcing warrant redemption by Arrowhead Research Corporation, dated May 4, 2005.



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: May 4, 2005



/s/ Joseph T. Kingsley

    Joseph T. Kingsley, Chief Financial Officer