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):  March 5, 2004


                         ARROWHEAD RESEARCH CORPORATION
                         ------------------------------
             (Exact name of registrant as specified in its charter)


            Delaware                  0-21898                 46-0408024
            --------                  -------                 ----------
  (State or other jurisdiction      (Commission            (I.R.S. Employer
      of incorporation)             File Number)          Identification No.)


              150 S. Los Robles, Ste. 480, Pasadena, CA        91101
              -----------------------------------------        -----
              (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)



ITEM 5.  OTHER EVENTS AND REGULATION FD DISCLOSURE.

     On  March  5,  2004, Arrowhead Research Corporation, a Delaware corporation
("Arrowhead  Research"), entered into an agreement with Dr. Harry A. Atwater and
the  California Institute of Technology ("Caltech") to form a new corporation to
commercialize  an  ultrathin  crystal  film  (nanofilm) technology that has been
developed  by  Dr.  Atwater  and his research group at Caltech. Pursuant to this
agreement,  Caltech  would  grant  the  new  company  a  fully-paid,  worldwide,
exclusive  license  to use the technology for commercial purposes. As payment in
full  for  the technology license, Caltech will be granted a warrant to purchase
shares  of  the  new  company's  common  stock.

     The  technology  is  expected  to  provide  advancements  in  semiconductor
technology,  in which device active region optical and electrical properties can
be  optimally  engineered  independently  of the underlying substrate's thermal,
dielectric  and  mechanical  properties.  The  technology enables fabrication of
high-quality single crystal semiconductor (e.g., InP, Ge, GaAs) and oxide (e.g.,
BaTiO3 , LiNbO3 , PMNPT) nanometer thickness films as surface layers transferred
onto  low-cost  substrates  (Si,  Sapphire,  glass)  and  would  enable superior
device/system  performance  at lower cost in applications such as photonics/ULSI
electronics  integration,  light-emitting  diode  and  laser  arrays,  HBTs  for
wireless  communications  and  high  efficiency  solar  cells.

     Arrowhead  Research  has agreed to provide $2,000,000 of initial funding to
the  new company, to purchase shares of preferred stock, and to contribute up to
$3,000,000 of additional capital as certain milestones in the development of its
business  are  met.  For  its investment, Arrowhead Research will own 80% of the
voting  securities  of  the  new  company,  with  the balance to be owned by Dr.
Atwater,  two  scientists  in  his  group,  and  a  president to be subsequently
identified.  Options will be granted to Dr. Atwater, the two scientists, and the
newly  to  be  selected  president of the company, which will vest over a 4-year
period.  In  the  event  that  all of the outstanding options and warrants fully
vested  and were exercised, along with additional options that are available for
future  grant  under a stock option plan, the ownership of Arrowhead Research in
the  new  company  would  be  reduced, but not below 50% of the then outstanding
voting  securities.

     As  owner  of all outstanding preferred stock, Arrowhead Research will have
the  right  at all times to elect a majority of the members of the new company's
Board  of  Directors,  with the remaining directors to be elected by Dr. Atwater
and  the  other holders of the new company's common stock.  The initial Board of
Directors of the new company will be comprised of 3 representatives of Arrowhead
Research  and  two  designees  of  Dr.  Atwater  and  his  group.

     Arrowhead  Research  has  agreed to sponsor additional research at Caltech,
under  the  direction  of  Dr.  Atwater,  to  exploit  a  new ferroelectric film
synthesis  technique  recently  developed by the Atwater group to make nanoscale
piezoelectric  devices  suitable  for  integration  into  microelectromechanical
systems  (MEMS)  on  silicon  substrates.

     Execution  of  the  agreement  was  publicly announced on March 9, 2004, by
means  of  a  Press  Release,  a  copy of which is filed as an amendment hereto.



ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.

     (c)  Exhibits.
          ---------
             A     -     Press Release dated March 9, 2004


                                   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 hereunto duly authorized.

Date:     March 9, 2004
                                            ARROWHEAD RESEARCH CORPORATION

                                            By:  /s/ R. Bruce Stewart
                                                 -----------------------------
                                                 R. Bruce Stewart, President



PRESS RELEASE                               Contact:          R. Bruce Stewart
Tuesday, March 9, 2004  07:00 ET            Telephone:        626.792.5549
                                            Email:            bruce@arrowres.com

                         ARROWHEAD RESEARCH CORPORATION
                         TO FORM NEW NANOTECH SUBSIDIARY

Pasadena,  California--(PR  Newswire)--March  9,  2004.  Arrowhead  Research
Corporation  (OTCBB: ARWR) announced today that it has entered into an agreement
to  form  a  new majority-owned subsidiary to commercialize an ultrathin crystal
film  (nanofilm)  technology that has been developed by Dr. Harry A. Atwater and
his  research  group  at  the  California Institute of Technology. The agreement
between  Arrowhead  Research  Corporation, Dr. Atwater, and Caltech provides for
the  grant  of  a fully-paid exclusive license to the new company to utilize the
technology  for  commercial  application.

The  technology is expected to provide advancements in semiconductor technology,
in which device active region optical and electrical properties can be optimally
engineered  independently  of the underlying substrate's thermal, dielectric and
mechanical properties. The technology enables fabrication of high-quality single
crystal  semiconductor  (e.g.,  InP,  Ge, GaAs) and oxide (e.g., BaTiO3, LiNbO3,
PMNPT)  nanometer  thickness  films  as surface layers transferred onto low-cost
substrates  (Si,  Sapphire,  glass)  and  would  enable  superior  device/system
performance  at  lower  cost  in applications such as photonics/ULSI electronics
integration,  light-emitting  diode  and  laser  arrays,  HBTs  for  wireless
communications  and  high  efficiency  solar  cells.

Arrowhead  has also agreed to sponsor research at Caltech under the direction of
Dr.  Atwater  to  exploit  a new ferroelectric film synthesis technique recently
developed  by the Atwater group to make nanoscale piezoelectric devices suitable
for  integration  into  microelectromechanical  systems  (MEMS)  on  silicon
substrates.

ABOUT  ARROWHEAD  RESEARCH  CORPORATION

Arrowhead  Research  Corporation  funds  research  at  universities  in emerging
scientific  areas,  initially  focusing  on  nanotechnology,  in  return for the
exclusive  rights  to  commercially  exploit  any  technologies  and  associated
intellectual  property  and  patents  developed as a result of this research. To
date,  the  company  has  entered  into  three  agreements  with  the California
Institute  of  Technology  and  three  of  its  faculty  who  are  conducting
nano-technology  research  and  is actively pursuing other potential partners at
Caltech  and  at  other  leading  research  institutions  and  universities.

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,  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, recent and forthcoming Quarterly Reports on Form
10-Q,  recent  Current  Reports  on  Forms  8-K and 8-K/A, 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.