Exhibit 10.24

ARROWHEAD RESEARCH CORPORATION

SUBSCRIPTION AGREEMENT

Ladies and Gentlemen:

1. Subscription; Payment. The undersigned (referred to herein as “Investor”),
intending to be legally bound under this Subscription Agreement (the
“Agreement”), hereby irrevocably agrees to purchase from Arrowhead Research
Corporation, a Delaware corporation (the “Company”), this subscription (the
“Subscription”) in the amount of $             (the “Capital Commitment”) for
$0.634 per Unit (as defined below) (the “Unit Price”), for a total of
             Units. which Unit shall consist of one (1) share of the Company’s
common stock, $0.001 par value per share (the “Common Stock,” and such shares of
Common Stock under the Units collectively referred to herein as the “Shares”)
and a warrant, in substantially the form attached hereto as Exhibit A, to
purchase a number of Shares to the number of Units purchased pursuant to the
Subscription (the Common Stock issuable upon exercise of the Warrants, the
“Warrant Shares”). Each Share and Warrant shall be referred to herein as a
“Unit” and collectively, the “Units”. This Subscription is submitted to Investor
in accordance with and subject to the terms and conditions described in this
Subscription Agreement.

Investor shall either: (i) enclose herewith a certified or official bank check
payable to the Company or (ii) transmit by wire transfer the amount of the
Capital Commitment. The Company shall deposit all proceeds received for the
Subscription in an account at Citizens Business Bank, pending acceptance of the
Subscription.

Contemporaneously with the execution and delivery of this Agreement, Investor is
executing and delivering a registration rights agreement, in substantially the
form attached hereto as Exhibit B (the “Registration Rights Agreement”),
pursuant to which, among other things, the Company will agree to provide certain
registration rights with respect to the Shares and the Warrant Shares under the
Securities Act of 1933, as amended, and the rules and regulations promulgated
thereunder (the “Securities Act”) and applicable state securities laws. This
Agreement, the Warrant, the Registration Rights Agreement and any documents,
certificates or instruments executed and delivered by the Company pursuant
hereto are collectively referred to herein as the “Transaction Agreements.”

2. Acceptance of Subscription; Closing. The Investor understands and agrees that
the Company in its sole discretion reserves the right to accept or reject this
or any other subscription in whole or in part, notwithstanding prior receipt by
Investor of notice of acceptance. If this Subscription is rejected by the
Company in whole or in part, the Company shall promptly return all funds
received from the Investor without interest or deduction and this Subscription
Agreement shall thereafter be of no further force or effect. If the Subscription
is accepted in whole or in part, the Company shall notify the Investor of the
date(s) of the closing of the purchase and sale of Units (each, a “Closing”),
which Closing shall occur after the close of market at the offices of the
Company.

 

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The Company shall deliver to the Investor one or more stock certificates and
Warrants evidencing the number of Units the Investor is purchasing pursuant to
the Subscription promptly after the Closing.

3. Representations and Warranties of the Company. The Company hereby represents
and warrants to the Investor as of the date of Closing as follows:

(a) The Company is a corporation duly organized, validly existing and in good
standing under the laws of the State of Delaware. The Company has all required
corporate power and authority to carry on its business as presently conducted,
to enter into and perform the Transaction Agreements and to carry out the
transactions contemplated hereby.

(b) The Transaction Agreements (including the sale and delivery of the Units and
the reservation for issuance and the subsequent issuance of Warrant Shares upon
exercise of the Warrants) are, or will be upon stockholder approval, if
necessary to increase the number of authorized shares of Common Stock of the
Company (the “Stockholder Approval”), valid and binding obligations of the
Company enforceable against the Company in accordance with their respective
terms, except (i) as such enforceability may be limited by applicable
bankruptcy, insolvency, reorganization, moratorium, liquidation or similar laws
relating to, or affecting generally the enforcement of, creditors’ rights and
remedies or by other principles of general application, (ii) as limited by laws
relating to the availability of specific performance, injunctive relief or other
equitable remedies and (iii) insofar as indemnification and contribution
provisions may be limited by applicable law. The execution, delivery and
performance of the Transaction Agreements executed and delivered by the Company
pursuant hereto and the issuance and delivery of the Units and the issuance of
the Warrant Shares upon exercise of the Warrants have been duly authorized by
all necessary corporate or other action of the Company, provided that the
Company shall obtain the Stockholder Approval, if necessary. When issued and
paid for in accordance with the terms of the Transaction Agreements, the Shares
and the issuance of Warrant Shares upon exercise of the Warrants will be duly
and validly issued, fully paid and non-assessable and free and clear of all
liens and encumbrances, other than restrictions on transfer provided for in the
Transaction Agreements or imposed by applicable securities laws, and shall not
be subject to preemptive or similar rights.

(c) The execution and delivery of the Transaction Agreements by the Company
pursuant hereto, and the issuance and delivery of the Units and the Warrant
Shares upon exercise of the Warrants, do not and will not: (i) violate, conflict
with, or result in a violation of, or constitute or result in a default or loss
of any benefit under, any provision of the Certificate of Incorporation, as
amended (the “Charter”), or bylaws of the Company, or cause the creation of any
encumbrance upon any of its assets; (ii) violate, conflict with, or result in a
violation of, or constitute a default under, any provision of any applicable
law, regulation or rule, or any order of, or any restriction imposed by, any
court or governmental agency of competent jurisdiction; (iii) require from the
Company any notice to, declaration or filing with, or consent or approval of,
any governmental authority or other third party; or (iv) violate, conflict with,
or result in a violation of, or constitute or result in a default under,
accelerate any obligation under, or give rise to a right of termination of, any
contract, agreement, permit, license, authorization or other obligation to which
the Company is a party or by which the Company or any of its assets are bound.

 

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(d) Assuming the accuracy of the representations and warranties of Investor in
this Agreement, the Shares and the Warrant Shares will be issued in compliance
with all applicable federal and state securities laws. As of the date of
Closing, the Company shall have reserved from its duly authorized capital stock
the number of shares of Common Stock or Preferred Stock issuable upon exercise
of the Warrants (without taking into account any limitations on the exercise of
the Warrants set forth in the Warrants). The Company shall, so long as any of
the Warrants are outstanding, take all action necessary to reserve and keep
available out of its authorized and unissued capital stock, solely for the
purpose of effecting the exercise of the Warrants, the number of shares of
Common Stock or Preferred Stock issuable upon exercise of the Warrants (without
taking into account any limitations on the exercise of the Warrants set forth in
the Warrants).

(e) The number of shares and type of all authorized, issued and outstanding
capital stock, options and other securities of the Company (whether or not
presently convertible into or exercisable or exchangeable for shares of capital
stock of the Company) is set forth in Schedule 3(e) hereto. The Company has not
issued any capital stock since the date of its most recently filed SEC Report
(as defined below) except as set forth in Schedule 3(e).

(f) The Company has filed all reports, schedules, forms, statements and other
documents required to be filed by it under the Securities Exchange Act of 1934,
as amended, and the rules and regulations promulgated thereunder (the “Exchange
Act”), including pursuant to Section 13(a) or 15(d) thereof, for the two years
preceding the date hereof (or such shorter period as the Company was required by
law or regulation to file such material) (the foregoing materials, including the
exhibits thereto and documents incorporated by reference therein, being
collectively referred to herein as the “SEC Reports”) on a timely basis or has
received a valid extension of such time of filing and has filed any such SEC
Reports prior to the expiration of any such extension, except where the failure
to file on a timely basis would not have or reasonably be expected to result in
a Material Adverse Effect (as defined below). As of their respective filing
dates, or to the extent corrected by a subsequent restatement, the SEC Reports
complied in all material respects with the requirements of the Securities Act
and the Exchange Act and the rules and regulations of the United Stated
Securities and Exchange Commission (the “Commission”) promulgated thereunder.
“Material Adverse Effect” means a material adverse effect on the results of
operations, assets, prospects, business or financial condition of the Company
and its consolidated subsidiaries, taken as a whole, except that any of the
following, either alone or in combination, shall not be deemed a Material
Adverse Effect: (i) effects caused by changes or circumstances affecting general
market conditions in the U.S. economy or which are generally applicable to the
industry in which the Company operates, provided that such effects are not borne
disproportionately by the Company, (ii) effects resulting from or relating to
the announcement or disclosure of the sale of the Units or other transactions
contemplated by this Agreement, or (iii) effects caused by any event, occurrence
or condition resulting from or relating to the taking of any action in
accordance with this Agreement.

(g) The financial statements of the Company included in the SEC Reports comply
in all material respects with applicable accounting requirements and the rules
and regulations of the Commission with respect thereto as in effect at the time
of filing (or to the extent corrected by a subsequent restatement). Such
financial statements have been prepared in accordance with U.S. generally
accepted accounting principles (“GAAP”) applied on a

 

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consistent basis during the periods involved, except as may be otherwise
specified in such financial statements or the notes thereto and except that
unaudited financial statements may not contain all footnotes required by GAAP,
and fairly present in all material respects the financial position of the
Company and its consolidated subsidiaries taken as a whole as of and for the
dates thereof and the results of operations and cash flows for the periods then
ended, subject, in the case of unaudited statements, to normal, immaterial
year-end audit adjustments.

(h) Since the date of the latest audited financial statements included within
the SEC Reports, except as specifically disclosed in a subsequent SEC Report
filed prior to the date hereof, (i) there have been no events, occurrences or
developments that have had or would reasonably be expected to have, either
individually or in the aggregate, a Material Adverse Effect, (ii) the Company
has not incurred any material liabilities (contingent or otherwise) other than
(A) trade payables and accrued expenses incurred in the ordinary course of
business consistent with past practice and (B) liabilities not required to be
reflected in the Company’s financial statements pursuant to GAAP or disclosed in
filings made with the Commission, (iii) the Company has not altered materially
its method of accounting or the manner in which it keeps its accounting books
and records, and (iv) the Company has not declared or made any dividend or
distribution of cash or other property to its stockholders or purchased,
redeemed or made any agreements to purchase or redeem any shares of its capital
stock (other than in connection with repurchases of unvested stock issued to
employees of the Company).

(i) Assuming the accuracy of Investor’s representations and warranties set forth
in Section 4 of this Agreement, no registration under the Securities Act is
required for the offer and sale of the Units by the Company to Investor under
the Transaction Agreements. The issuance and sale of the Units hereunder does
not contravene the rules and regulations of the NASDAQ Capital Market.

4. Representations and Warranties. Investor hereby acknowledges, represents and
warrants to, and agrees with, the Company as follows:

(a) Investor understands that the offering and sale of the Units are intended to
be exempt from registration under the Securities Act, by virtue of Section 4(2)
of the Securities Act, and in accordance therewith and in furtherance thereof,
Investor represents and warrants and agrees as follows:

(i) Investor has been afforded an opportunity to review information relating to
the Company, the Company’s business and finances, the offering by the Company of
the Units and any and all other information deemed relevant by Investor in order
to make an informed investment decision regarding the Units (collectively, the
“Information”), and has reviewed and received such Information and understands
the Information and the Transaction Agreements;

(ii) Investor acknowledges that all documents, records and books pertaining to
this investment (including, without limitation, the Information) have been made
available for inspection by Investor, Investor’s attorney, accountant or
advisor(s);

 

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(iii) Investor and/or Investor’s advisor(s) has/have had a reasonable
opportunity to ask questions of and receive answers from a person or persons on
behalf of the Company concerning the offering of the Units and all such
questions have been answered to the full satisfaction of Investor;

(iv) No oral or written representations have been made other than as stated, or
in addition to those stated, in the Information, and no oral or written
information furnished to Investor or Investor’s advisors in connection with the
offering of the Units was in any way inconsistent with the information stated in
the Information;

(v) Investor is not subscribing for the Units as a result of or subsequent to
any advertisement, article, notice, other communication published in any
newspaper, magazine or similar media or broadcast over television or radio, or
presented at any seminar or meeting, or any solicitation of a subscription by a
person other than a representative of the Company;

(vi) If Investor is a natural person, Investor has reached the age of majority
in the state in which Investor resides;

(vii) The address set forth below is Investor’s true and correct domicile;

(viii) Investor has adequate means of providing for Investor’s current financial
needs and contingencies, is able to bear the substantial economic risks of an
investment in the Units for an indefinite period of time, has no need for
liquidity in such investment, and, at the present time, could afford a complete
loss of such investment;

(ix) Investor has such knowledge and experience in financial, tax and business
matters so as to enable Investor to utilize the information made available to
Investor in connection with the offering of the Units to evaluate the merits and
risks of an investment in the Company and to make an informed investment
decision with respect thereto;

(x) Investor is not relying on the Company with respect to the legal, tax and
other economic considerations of an investment and has obtained, or had the
opportunity to obtain the advice of Investor’s own legal, tax and other
advisors;

(xi) Investor will not sell or otherwise transfer the Units without registration
under the Securities Act or applicable state securities laws or an exemption
therefrom. The Units have not been registered under the Securities Act or under
the securities laws of any other jurisdiction. Investor represents that Investor
is purchasing the Units for Investor’s own account, for investment and not with
a view to resale or distribution except in compliance with the Securities Act.
Investor has not offered or sold any portion of the Units being acquired nor
does Investor have any present intention of selling, distributing or otherwise
disposing of any portion of the Units, either currently or after the passage of
a

 

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fixed or determinable period of time or upon the occurrence or nonoccurrence of
any predetermined event or circumstance in violation of the Securities Act.
Investor is aware that an exemption from the registration requirements of the
Securities Act pursuant to Rule 144 promulgated thereunder is not presently
available; that the Company has no obligation to register Investor’s Units
(except as provided in the Registration Rights Agreement) or to make available
an exemption from the registration requirements pursuant to such Rule 144 or any
successor rule for resale of Investor’s Units;

(xii) Investor (A) was not organized or reorganized for the specific purpose of
acquiring the Units, (B) has made investments prior to the date hereof, and each
beneficial owner thereof has and will share the same proportion in each
investment and (C) Investor’s investment in the Company will not constitute more
than forty percent (40%) of Investor’s total capital;

(xiii) INVESTOR UNDERSTANDS AND ACKNOWLEDGES THAT HIS OR HER INVESTMENT IN THE
COMPANY INVOLVES A HIGH DEGREE OF RISK AND IS SUITABLE ONLY FOR INVESTORS OF
SUBSTANTIAL MEANS WHO HAVE NO IMMEDIATE NEED FOR LIQUIDITY OF THE AMOUNT
INVESTED, AND THAT SUCH INVESTMENT INVOLVES A RISK OF LOSS OF ALL OR A
SUBSTANTIAL PART OF SUCH INVESTMENT; and

(xiv) Investor is an “accredited investor” within the meaning of Rule 501 of
Regulation D promulgated under the Securities Act.

(b) Investor’s overall commitment to investments which are not readily
marketable is reasonable in relation to Investor’s net worth.

(c) Investor hereby agrees to provide such information and to execute and
deliver such documents as may reasonably be necessary to comply with any and all
laws and ordinances to which the Company is subject, including, without
limitation, such additional information as the Company may deem appropriate with
regard to Investor’s suitability.

(d) Investor acknowledges:

(i) In making an investment decision Investor has relied on Investor’s own
examination of the Company and the terms of the offering of the Units, including
the merits and risks involved. THE UNITS OFFERED IN THIS SUBSCRIPTION AGREEMENT
HAVE NOT BEEN RECOMMENDED BY ANY FEDERAL OR STATE SECURITIES COMMISSION OR
REGULATORY AUTHORITY. FURTHERMORE, THE FOREGOING AUTHORITIES HAVE NOT CONFIRMED
THE ACCURACY OR DETERMINED THE ADEQUACY OF THE INFORMATION OR THIS DOCUMENT. ANY
REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE;

 

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(ii) Investor, if executing the Transaction Agreements in a representative or
fiduciary capacity, has full power and authority to execute and deliver the
Transaction Agreements in such capacity and on behalf of the subscribing
individual, ward, partnership, trust, estate, corporation, limited liability
company or other entity for whom Investor is executing the Transaction
Agreements, and such individual, ward, partnership, trust, estate, corporation,
limited liability company or other entity has full right and power to perform
pursuant to the Transaction Agreements and make an investment in the Company;
and

(iii) The representations, warranties, and agreements of Investor contained
herein and in any other writing delivered in connection with the transactions
contemplated hereby shall be true and correct in all respects on and as of the
date of the sale of the Units as if made on and as of such date and shall
survive the execution and delivery of the Transaction Agreements and the
purchase of the Units.

(e) Investor understands that the Units being offered and sold to it in reliance
on specific exemptions from the registration requirements of United States
federal and state securities laws and that the Company is relying in part upon
the truth and accuracy of, and such Investor’s compliance with, the
representations, warranties, agreements, acknowledgements and understandings of
such Investor set forth herein in order to determine the availability of such
exemptions and the eligibility of such Investor to acquire the Units.

5. Conditions to Closing.

(a) The obligation of Investor to acquire Units at the Closing is subject to the
fulfillment of the following, on or prior to the date of Closing of the
following (unless waived by Investor):

(i) The representations and warranties of the Company contained in Section 3
herein shall be true and correct in all material respects (except for those
representations and warranties which are qualified as to materiality, in which
case such representations and warranties shall be true and correct in all
respects) as of the date of Closing, as though made on and as of such date,
except for such representations and warranties that speak as of a specific date.

(ii) The Company shall have performed, satisfied and complied in all material
respects with all covenants, agreements and conditions required by the
Transaction Agreements to be performed, satisfied or complied with by it at or
prior to the Closing and shall have obtained in a timely fashion any and all
consents, permits, approvals, registrations and waivers necessary for
consummation of the purchase and sale of the Units, all of which shall be and
remain so long as necessary in full force and effect.

(iii) the Company shall deliver to the Investor this Agreement and the
Registration Rights Agreement, duly executed by the Company;

 

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(iv) the NASDAQ Capital Market shall have approved the listing of additional
shares application for the Shares and Warrant Shares.

(b) On or prior to the Closing, the Investor shall issue, deliver or cause to be
delivered to the Company the following:

(i) The representations and warranties of the Investor contained in Section 4
herein shall be true and correct in all material respects (except for those
representations and warranties which are qualified as to materiality, in which
case such representations and warranties shall be true and correct in all
respects) as of the date when made and as of the date of Closing, as though made
on and as of such date, except for such representations and warranties that
speak as of a specific date.

(ii) Investor shall have performed, satisfied and complied in all material
respects with all covenants, agreements and conditions required by the
Transaction Agreements to be performed, satisfied or complied with by it at or
prior to the Closing and shall have obtained in a timely fashion any and all
consents, permits, approvals, registrations and waivers necessary for
consummation of the purchase and sale of the Units, all of which shall be and
remain so long as necessary in full force and effect.

(iii) Investor shall deliver to the Company:

(1) this Agreement and the Registration Rights Agreement, duly executed by
Investor; and

(2) the Capital Commitment, in United States dollars and in immediately
available funds, and completed Internal Revenue Service Form W-9.

7. Transfer Restrictions.

(a) The Shares may only be disposed of in compliance with state and federal
securities laws. In connection with any transfer of Shares, other than pursuant
to an effective registration statement or Rule 144 under the Securities Act, to
the Company or to an Affiliate of a Investor or in connection with a pledge as
contemplated in Section 7 (b), the Company may require the transferor thereof to
provide to the Company an opinion of counsel selected by the transferor and
reasonably acceptable to the Company, the form and substance of which opinion
shall be reasonably satisfactory to the Company, to the effect that such
transfer does not require registration of such transferred Shares under the
Securities Act. As a condition of transfer, any such transferee shall agree in
writing to be bound by the terms of this Agreement and shall have the rights of
a Investor under this Agreement and the Registration Rights Agreement.

 

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(b) The Investors agree to the imprinting, so long as is required by this
Section 7, of a legend on any of the Shares in the following form:

THIS SECURITY HAS NOT BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE
COMMISSION OR THE SECURITIES COMMISSION OF ANY STATE IN RELIANCE UPON AN
EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
“SECURITIES ACT”), AND, ACCORDINGLY, MAY NOT BE OFFERED OR SOLD EXCEPT PURSUANT
TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OR PURSUANT TO
AN AVAILABLE EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO, THE
REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND IN ACCORDANCE WITH
APPLICABLE STATE SECURITIES LAWS AS EVIDENCED BY A LEGAL OPINION OF COUNSEL TO
THE TRANSFEROR TO SUCH EFFECT, THE SUBSTANCE OF WHICH SHALL BE REASONABLY
ACCEPTABLE TO THE COMPANY. THIS SECURITY MAY BE PLEDGED IN CONNECTION WITH A
BONA FIDE MARGIN ACCOUNT WITH A REGISTERED BROKER-DEALER OR OTHER LOAN WITH A
FINANCIAL INSTITUTION THAT IS AN “ACCREDITED INVESTOR” AS DEFINED IN RULE 501(a)
UNDER THE SECURITIES ACT OR OTHER LOAN SECURED BY SUCH SECURITIES.

The Company acknowledges and agrees that a Investor may from time to time pledge
pursuant to a bona fide margin agreement with a registered broker-dealer or
grant a security interest in some or all of the Shares to a financial
institution that is an “accredited investor” as defined in Rule 501(a) under the
Securities Act and who agrees to be bound by the provisions of this Agreement
and the Registration Rights Agreement and, if required under the terms of such
arrangement, such Investor may transfer pledged or secured Shares to the
pledgees or secured parties. Such a pledge or transfer would not be subject to
approval of the Company and no legal opinion of legal counsel of the pledgee,
secured party or pledgor shall be required in connection therewith. Further, no
notice shall be required of such pledge. At the appropriate Investor’s expense,
the Company will execute and deliver such reasonable documentation as a pledgee
or secured party of Shares may reasonably request in connection with a pledge or
transfer of the Shares, including, if the Shares are subject to registration
pursuant to the Registration Rights Agreement, the preparation and filing of any
required prospectus supplement under Rule 424(b)(3) under the Securities Act or
other applicable provision of the Securities Act to appropriately amend the list
of Selling Stockholders thereunder.

(c) Certificates evidencing the Shares shall not contain any legend (including
the legend set forth in Section 7(b)), (i) while a registration statement
(including the Registration Statement) covering the resale of such security is
effective under the Securities Act, or (ii) following any sale of such Shares
pursuant to Rule 144, or (iii) if such Shares or Warrant Shares are eligible for
sale without restriction under Rule 144, or (iv) if such legend is not required
under applicable requirements of the Securities Act (including judicial
interpretations and pronouncements issued by the staff of the Commission). The
Company shall cause its counsel to issue a legal opinion to the Transfer Agent
promptly after the Effective Date if required by the Transfer Agent to effect
the removal of the legend hereunder. If any portion of a Warrant is exercised at
a time when there is an effective registration statement to cover the resale of
the Warrant Shares, such Warrant Shares shall be issued free of all legends. The
Company agrees that following the Effective Date or at such time as such legend
is no longer required under this Section 7(c), it will use reasonable efforts
to, within three Business Days following the delivery by a Investor to the
Company or the Transfer Agent of a certificate representing Shares or Warrant
Shares, as the case may be, issued with a restrictive legend (such third
Business Day, the “Legend Removal Date”), deliver or cause to be delivered to
such Investor, a certificate representing such shares free from all restrictive
legends. The Company may not make any notation on its records or give
instructions to the Transfer Agent that enlarge the restrictions on transfer set
forth in this Section. Certificates for Securities subject to legend removal
hereunder shall be transmitted by the Transfer Agent to the Investor by
crediting the account of the Investor’s prime broker with the Depository Trust
Company System as directed by such Investor.

 

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(d) Each Investor, severally and not jointly with the other Investors, agrees
that such Investor will sell any Securities pursuant to either the registration
requirements of the Securities Act, including any applicable prospectus delivery
requirements, or an exemption therefrom, and that if Securities are sold
pursuant to a Registration Statement, they will be sold in compliance with the
plan of distribution set forth therein, and acknowledges that the removal of the
restrictive legend from certificates representing Shares as set forth in this
Section 7 is predicated upon the Company’s reliance upon this understanding.

8. Indemnification. Investor agrees to indemnify and hold harmless the Company
its officers, members, directors, employees, consultants, advisors, attorneys,
agents and affiliates against any and all loss, liability, claim, damage and
expense whatsoever (including, without limitation, any and all expenses
reasonably incurred in investigating, preparing, or defending against any
litigation commenced or threatened or any claim whatsoever) arising out of or
based upon any false representation or warranty or breach or failure by Investor
to comply with any covenant or agreement made by Investor herein or in any other
document furnished by Investor to any of the foregoing in connection with this
transaction.

9. Irrevocability; Binding Effect; Entire Agreement. Investor hereby
acknowledges and agrees that the Subscription hereunder is irrevocable by
Investor, that, except as required by law, Investor is not entitled to cancel,
terminate or revoke this Subscription Agreement or any agreements of Investor
hereunder, and that this Subscription Agreement and such other agreements shall
survive the death or disability of Investor and shall be binding upon and inure
to the benefit of the parties and their heirs, executors, administrators,
successors, legal representatives and permitted assigns. If Investor is more
than one person, the obligations of Investor hereunder shall be joint and
several and the agreements, representations, warranties and acknowledgments
herein contained shall be deemed to be made by and be binding upon each such
person and his/her heirs, executors, administrators, successors, legal
representatives and permitted assigns. The Transaction Agreements sets forth the
entire agreement and understanding among the parties hereto with respect to the
transactions contemplated hereby and supersedes any and all prior agreements and
understandings relating to the subject matter hereof.

10. Modification. Neither this Subscription Agreement nor any provisions hereof
shall be waived, modified, discharged or terminated except by an instrument in
writing signed by the party against whom any such waiver, modification,
discharge or termination is sought.

 

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11. Notices. All notices and other communications required or permitted
hereunder shall be in writing and shall be mailed by registered or certified
mail, postage prepaid, or otherwise delivered by facsimile transmission, by hand
or by messenger, addressed:

 

  (a) If to the Company, to:

Arrowhead Research Corporation

201 South Lake Avenue, Suite 703

Pasadena, California 91101

Attention: President;

Facsimile number 626-792-5554

or at such other address as the Company shall have furnished to the Investors,
with a copy (which shall not constitute notice) to Goodwin Procter LLP, Three
Embarcadero Center, 24th Floor, Attn.: Ryan Murr.

(b) If to Investor, at the address set forth on the signature page hereof (or,
in either case, to such other address as the party shall have furnished in
writing in accordance with the provisions of this Section 11).

Each such notice or other communication shall for all purposes of this Agreement
be treated as effective or having been given when delivered if delivered
personally, if sent by facsimile, the first business day after the date of
confirmation that the facsimile has been successfully transmitted to the
facsimile number for the party notified, or, if sent by mail, at the earlier of
its receipt or 72 hours after the same has been deposited in a regularly
maintained receptacle for the deposit of the United States mail, addressed and
mailed as aforesaid.

12. Assignability. This Subscription Agreement and the rights and obligations
hereunder are not transferable or assignable by the Investor.

13. Applicable Law; Jurisdiction. This Agreement shall be governed in all
respects by the internal laws of the State of Delaware without regard to
conflict of laws provisions. The parties hereto (i) designate the courts of the
State of Delaware as the forum where all matters pertaining to this Agreement
may be adjudicated, and (ii) by the foregoing designation, consent to the
exclusive jurisdiction and venue of such courts for the purpose of adjudicating
all matters pertaining to this Agreement.

14. Severability. If any provision of this Agreement is held to be invalid or
unenforceable in any respect, the validity and enforceability of the remaining
terms and provisions of this Agreement shall not in any way be affected or
impaired thereby and the parties will attempt to agree upon a valid and
enforceable provision that is a reasonable substitute therefor, and upon so
agreeing, shall incorporate such substitute provision in this Agreement.

15. Counterparts. This Agreement may be executed by facsimile, in any number of
counterparts, each of which shall be an original and all of which together shall
constitute one instrument.

16. Nature of Subscriber. Investor is (check one):

 

¨    (a)   One or more individuals ¨    (b)   A corporation

 

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¨    (c)   A partnership ¨    (d)   A trust ¨    (e)   Another entity or
organization, namely                                                       
(please specify)

17. Limitations on Investment in Investment Companies.

If Investor is not an individual, check the box below which correctly describes
the application of the following statement to your situation: Investor would
not, upon acquiring the Shares, have more than ten percent (10%) of its assets
invested in one or more investment companies that rely solely on the exclusion
from the definition of “investment company” provided in Section 3(c)(1)(A) of
the Investment Company Act of 1940:*

 

¨    True ¨    False

If the “False” box is checked, Investor will as of the Closing have
                     individual stockholders, partners or other record owners
and non-individual stockholders, partners or other record owners. Those
non-individual stockholders, partners or other record owners to whom application
of the above statement would be “False” have an aggregate of
                     ultimate beneficial owners who are either individuals or to
whom application of the above statement would be “True.”

18. Matters Relating to the Undersigned’s Ownership of the Shares.

(a) All correspondence relating to Investor’s investment should be sent (check
one):

 

¨    (i)   to the address of Investor set forth on the signature page hereof

 

 

* Section 3(c)(1)(A) provides, in pertinent part:

“[N]one of the following persons is an investment company. . .

(1) Any issuer whose outstanding securities (other than short-term paper) are
beneficially owned by not more than one hundred persons and which is not making
and does not presently propose to make a public offering of its securities. For
purposes of this paragraph:

(A) Beneficial ownership by a company shall be deemed to be beneficial ownership
by one person, except that, if such company owns 10 percent or more of the
outstanding voting securities of the issuer, the beneficial ownership shall be
deemed to be that of the holders of such company’s outstanding securities (other
than short-term paper) unless, as of the date of the most recent acquisition by
such company of securities of that issuer, the value of all securities owned by
such company of all issuers which are or would, but for the exception set forth
in this subparagraph, be excluded from the definition of investment company
solely by this paragraph, does not exceed 10 percent of the value of the
company’s total assets. . . .”

 

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¨    (ii)   to the following address:

 

 

           

 

           

 

           

(b) Investor may be contacted by telephone at the following telephone numbers:

 

(i)    Home telephone:  

 

   (ii)    Business telephone:  

 

   (iii)    Facsimile telephone:  

 

  

(c) Investor may be contacted by electronic mail at the following email address:

 

 

                

 

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SUBSCRIPTION AGREEMENT SIGNATURE PAGE

FOR INDIVIDUALS

IN WITNESS WHEREOF, the undersigned executed this Agreement this      day of
            , 2009.

 

No. of Units Purchased:    

 

    Print Name

 

       

 

    Signature of Investor    

 

    Social Security Number        

 

   

 

    Residence Address

If the purchaser has indicated that the Shares will be held as JOINT TENANTS, as
TENANTS IN COMMON, or as COMMUNITY PROPERTY, please complete the following:

 

 

Print Name of Spouse or Other Purchaser

 

Signature of Spouse or Other Purchaser

 

Social Security Number

 

ACCEPTED AND AGREED:         ARROWHEAD RESEARCH CORPORATION         By:  

 

        Name:           Title:           Dated:             , 2009

 

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SUBSCRIPTION AGREEMENT SIGNATURE PAGE

FOR PARTNERSHIPS, CORPORATIONS, TRUSTS, OR OTHER ENTITIES

IN WITNESS WHEREOF, the undersigned has executed this Agreement this      day of
            , 2009.

 

No. of Units Purchased:      

 

      Print Name of Partnership, Corporation,

 

      Trust or other Entity       By:   

 

         (Signature of Authorized Signatory)       Name:   

 

      Title:   

 

      Address:   

 

        

 

      Jurisdiction where organized:                                             
Taxpayer Identification       Number:   

 

      Date of Formation:                                       
                          Address of Chief Executive Officer of Subscriber:   
  

 

     

 

 

ACCEPTED AND AGREED:         ARROWHEAD RESEARCH CORPORATION         By:  

 

        Name:           Title:           Dated:             , 2009