EX-4.5





 Exhibit 4.5 

ARROWHEAD PHARMACEUTICALS, INC. 
 2021 INCENTIVE PLAN

 1. DEFINED TERMS 
  

 
 Exhibit A, which is incorporated by
reference, defines the terms used in the Plan and sets forth certain operational rules related to those terms. 
 2. PURPOSE 

 
  

The Plan has been established to advance the interests of the Company by providing for the grant to Participants of Stock-based and other incentive Awards.

 3. ADMINISTRATION 
  

 
 The Administrator has discretionary authority, subject
only to the express provisions of the Plan, to interpret the Plan; determine eligibility for and grant Awards; determine, modify or waive the terms and conditions of any Award; prescribe forms, rules and procedures relating to the Plan; determine
whether Awards should be settled in cash and/or shares of Stock; and otherwise do all things necessary or appropriate to carry out the purposes of the Plan. Determinations of the Administrator made under the Plan will be conclusive and will bind all
parties. 
 4. LIMITS ON AWARDS UNDER THE PLAN 
  

 
 (a) Number of Shares. The maximum
number of shares of Stock that may be delivered in satisfaction of Awards under the Plan is 8,000,000, reduced by any shares of Common Stock subject to awards made under the Prior Plan after January 1, 2021. Shares of Stock subject to
outstanding awards under the Prior Plans as of January 1, 2021 that, after January 1, 2021, are canceled, expired, forfeited or otherwise not issued under such award (other than as a result of being tendered or withheld to pay the exercise
price or withholding taxes in connection with any such awards) or settled in cash shall be added to the number of shares of Stock issuable under the Plan. No more than 8,000,000 shares of Stock may be delivered in satisfaction of ISOs awarded under
the Plan. Nothing in this Section 4(a) will be construed as requiring that any, or any fixed number of, ISOs be awarded under the Plan. For purposes of this Section 4(a), the number of shares of Stock delivered in satisfaction of Awards
will be determined (i) by treating as having been delivered any shares of Stock underlying the portion of any Award that is settled in Stock, (ii) by treating as having been delivered any shares of Stock tendered to or withheld by the
Company from any Award in payment of the exercise price of any Award requiring exercise or in satisfaction of the tax withholding requirements with respect to any Award, and (iii) by treating as having been delivered any shares of Stock
purchased by the Company with proceeds from the exercise of Stock Options. Stock underlying the portion of any Award that expires, terminates or is forfeited or is settled in cash prior to the issuance of Stock thereunder shall not be counted as
having been delivered under the Plan. To the extent consistent with the requirements of Section 422 and the regulations thereunder, and with other applicable legal requirements (including applicable stock exchange requirements), Stock issued
under awards of an acquired company that are converted, replaced or adjusted in connection with the acquisition shall not reduce the number of shares of Stock available for Awards under the Plan. 

(b) Type of Shares. Stock delivered by the Company under the Plan may be authorized but unissued Stock or previously issued Stock
acquired by the Company. No fractional shares of Stock will be delivered under the Plan. 












 5. ELIGIBILITY AND PARTICIPATION 

 
  

The Administrator will select Participants from among key Employees and directors of, and consultants and advisors to, the Company and its Affiliates.
Eligibility for ISOs is limited to individuals described in the first sentence of this Section 5 who are employees of the Company or of a “parent corporation” or “subsidiary corporation” of the Company as those terms are
defined in Section 424 of the Code. Eligibility for Stock Options other than ISOs is limited to individuals described in the first sentence of this Section 5 who are providing direct services on the date of grant of the Stock Option to
either the Company or to a subsidiary of the Company that would be described in the first sentence of Treas. Regs. §1.409A-1(b)(5)(iii)(E). 

6. RULES APPLICABLE TO AWARDS 
  

 
 (a) All Awards. 

(1) Award Provisions. The Administrator will determine the terms of all Awards, subject to the limitations provided herein. By accepting
(or, under such rules as the Administrator may prescribe, being deemed to have accepted) an Award, the Participant will be deemed to have agreed to the terms of the Award and the Plan. Notwithstanding any provision of this Plan to the contrary,
awards of an acquired company that are converted, replaced or adjusted in connection with the acquisition may contain terms and conditions that are inconsistent with the terms and conditions specified herein, as determined by the Administrator. 

(2) Term of Plan. No Awards may be made after ten years from the Date of Adoption, but previously granted Awards may continue beyond that
date in accordance with their terms. 
 (3) Transferability. Neither ISOs nor, except as the Administrator otherwise expressly provides
in accordance with the third sentence of this Section 6(a)(3), other Awards may be transferred other than by will or by the laws of descent and distribution. During a Participant’s lifetime, ISOs (and, except as the Administrator otherwise
expressly provides in accordance with the third sentence of this Section 6(a)(3), SARs and NSOs) may be exercised only by the Participant. The Administrator may permit the gratuitous transfer (i.e., transfer not for value) of Awards
other than ISOs to any transferee eligible to be covered by the provisions of Form S-8 (under the Securities Act of 1933, as amended), subject to such limitations as the Administrator may impose.

 (4) Vesting, etc. Subject to Section 6(a)(5), the Administrator will determine the time or times at which an Award will vest or
become exercisable and the terms on which a Stock Option or SAR will remain exercisable. Without limiting the foregoing, the Administrator may at any time accelerate the vesting or exercisability of an Award, regardless of any adverse or potentially
adverse tax or other consequences resulting from such acceleration. Unless the Administrator expressly provides otherwise, however, the following rules will apply if a Participant’s Employment ceases: 

(A) Immediately upon the cessation of the Participant’s Employment and except as provided in (B), (C), and (D) below, each Stock Option and SAR that
is then held by the Participant or by the Participant’s permitted transferees, if any, will cease to be exercisable and will terminate and all other Awards that are then held by the Participant or by the Participant’s permitted
transferees, if any, to the extent not already vested will be forfeited. 
 (B) Subject to (C), (D) and (E) below, all Stock Options and SARs held
by the Participant or the Participant’s permitted transferees, if any, immediately prior to the cessation of the Participant’s Employment, to the extent then exercisable, will remain exercisable for the lesser of (i) a period of three
months and (ii) the period ending on the latest date on which such Stock Option or SAR could have been exercised without regard to this Section 6(a)(4), and will thereupon immediately terminate. 

(C) All Stock Options and SARs held by a Participant or the Participant’s permitted transferees, if any, immediately prior to the cessation of the
Participant’s Employment due to his or her death, to the extent then exercisable, will remain exercisable for the lesser of (i) a period of twelve months and (ii) the period ending on the latest date on which such Stock Option or SAR
could have been exercised without regard to this Section 6(a)(4), and will thereupon immediately terminate. 

  
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 (D) All Stock Options and SARs held by a Participant or the Participant’s permitted transferees, if
any, immediately prior to the cessation of the Participant’s Employment due to his or her “permanent and total disability” (within the meaning of Section 22(e)(3) of the Code, to the extent then exercisable, will remain
exercisable for the lesser of (i) a period of six months and (ii) the period ending on the latest date on which such Stock Option or SAR could have been exercised without regard to this Section 6(a)(4), and will thereupon immediately
terminate. 
 (E) All Awards (whether or not exercisable) held by a Participant or the Participant’s permitted transferees, if any, immediately prior
to the cessation of the Participant’s Employment will immediately terminate upon such cessation of Employment if the termination is for Cause or occurs in circumstances that in the sole determination of the Administrator would have constituted
grounds for the Participant’s Employment to be terminated for Cause. 
 (5) Minimum Vesting; Holding Period. Except as otherwise provided
in this Section 6(a)(5), no Award shall be granted with terms providing for any right of vesting, exercise or lapse of vesting requirements earlier than a date that is at least one (1) year following the date of grant (or, in the case of
vesting based upon performance objectives, exercise and vesting restrictions cannot lapse earlier than the one (1) year anniversary measured from the date of the commencement of the period over which performance is measured). Notwithstanding
the foregoing, the Administrator may grant up to a maximum of five percent (5%) of the aggregate number of shares available for issuance under the Plan (for purposes of counting shares against the five percent (5%) limitation, the share counting
rules under Section 4(a) shall apply) that do not comply with the one (1) year minimum vesting and exercise requirements set forth in the preceding sentence. In addition, Awards granted
to non-employee directors need not comply with the one (1) year minimum vesting and exercise requirements so long as the Awards provide for a right of exercise or lapse of any vesting
obligations no earlier than the next annual stockholder meeting date following the grant date. In addition to the minimum vesting and exercise requirements in this Section 6(a)(5), any Awards granted to the Company’s Chief Executive
Officer shall be granted with terms providing that the shares issued upon exercise or settlement of any such Award (net of tax withholding) may not be transferred or otherwise disposed of by the Company’s Chief Executive Officer for at least
twelve (12) months following the date of such exercise or settlement. 
 (6) Additional Restrictions. The Administrator may
cancel, rescind, withhold or otherwise limit or restrict any Award at any time if the Participant is not in compliance with all applicable provisions of the Award agreement and the Plan, or if the Participant breaches any agreement with the Company
or its Affiliates with respect to non-competition, non-solicitation or confidentiality. Without limiting the generality of the foregoing, the
Administrator may recover Awards made under the Plan and payments under or gain in respect of any Award in accordance with any applicable Company clawback or recoupment policy, as such policy may be amended and in effect from time to time, or as
otherwise required by law or applicable stock exchange listing standards, including, without limitation, Section 10D of the Exchange Act, or any stock exchange or similar rule adopted under said Section. 

(7) Taxes. The grant of an Award and the delivery, vesting and retention of Stock, cash or other property under an Award are conditioned
upon full satisfaction by the Participant of all tax withholding requirements with respect to the Award. The Administrator will prescribe such rules for the withholding of taxes as it deems necessary or appropriate. The Administrator may, but need
not, hold back shares of Stock from an Award or permit a Participant to tender previously owned shares of Stock in satisfaction of tax withholding requirements (only up to the amount permitted that will not cause an adverse accounting consequence or
cost). 
 (8) Dividend Equivalents, Etc. The Administrator may provide for the payment of amounts (on terms and subject to conditions
established by the Administrator) in lieu of cash dividends or other cash distributions with respect to Stock subject to an Award whether or not the holder of such Award is otherwise entitled to share in the actual dividend or distribution in
respect of such Award. Any entitlement to dividend equivalents or similar entitlements will be established and administered either consistent with an exemption from, or in compliance with, the requirements of Section 409A. Dividends or dividend
equivalent amounts payable in respect of Awards that are subject to restrictions will be subject to the same vesting and forfeiture restrictions as apply to the Awards to which they relate. 

(9) Rights Limited. Nothing in the Plan or in any Award will be construed as giving any person the right to continued employment or
service with the Company or its Affiliates, or any rights as a stockholder except as to shares of Stock actually issued under the Plan; nor will anything in the Plan or in any Award affect the right of the Company or its Affiliates to discharge or
discipline a Participant at any time. The loss of existing or potential profit in Awards will not constitute an element of damages in the event of termination of Employment for any reason, even if the termination is in violation of an obligation of
the Company or any Affiliate to the Participant. 
 (10) Coordination with Other Plans. Awards under the Plan may be granted in tandem with,
or in satisfaction of or substitution for, other Awards under the Plan or awards made under other compensatory plans or programs of the Company or its Affiliates. For example, but without limiting the generality of the foregoing, awards under other


  
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compensatory plans or programs of the Company or its Affiliates may be settled in Stock (including, without limitation, Unrestricted Stock) if the Administrator so determines, in which case the
shares delivered will be treated as awarded under the Plan (and will reduce the number of shares thereafter available under the Plan in accordance with the rules set forth in Section 4). 

(11) Section 409A. Each Award will contain such terms as the Administrator determines, and will be construed and administered, such
that the Award either qualifies for an exemption from the requirements of Section 409A or satisfies such requirements. 
 (b) Stock
Options and SARs. 
 (1) Time And Manner Of Exercise. Unless the Administrator expressly provides otherwise, no Stock
Option or SAR will be deemed to have been exercised until the Administrator receives a notice of exercise (in form acceptable to the Administrator), which may be an electronic notice, signed (including electronic signature in form acceptable to the
Administrator) by the appropriate person and accompanied by any payment required under the Award. A Stock Option or SAR exercised by any person other than the Participant will not be deemed to have been exercised until the Administrator has received
such evidence as it may require that the person exercising the Award has the right to do so. 
 (2) Exercise Price. The exercise price
(or the base value from which appreciation is to be measured) of each Award requiring exercise will be no less than 100% (or in the case of an ISO granted to a ten-percent shareholder within the
meaning of subsection (b)(6) of Section 422, 110%) of the Fair Market Value of the Stock subject to the Award, determined as of the date of grant, or such higher amount as the Administrator may determine in connection with the grant. Except in
connection with a corporate transaction involving the Company (which term shall include, without limitation, any stock dividend, stock split, extraordinary cash dividend, recapitalization, reorganization, merger, consolidation, split-up, spin-off, combination, or exchange of shares) or as otherwise contemplated by Section 7 of the Plan, the Company may not, without obtaining stockholder approval,
(A) amend the terms of outstanding Stock Options or SARs to reduce the exercise price or base value of such Stock Options or SARs, (B) cancel outstanding Stock Options or SARs in exchange for Stock Options or SARs with an exercise price or
base value that is less than the exercise price or base value of the original Stock Options or SARs, or (C) cancel outstanding Stock Options or SARs that have an exercise price or base value greater than the Fair Market Value of a share of
Stock on the date of such cancellation in exchange for cash or other consideration. 
 (3) Payment Of Exercise Price. Where the
exercise of an Award is to be accompanied by payment, payment of the exercise price will be by cash or check acceptable to the Administrator or by such other legally permissible means, if any, as may be acceptable to the Administrator. 

(4) Maximum Term. Stock Options and SARs will have a maximum term not to exceed ten (10) years from the date of grant (or five
(5) years from the date of grant in the case of an ISO granted to a ten-percent shareholder described in Section 6(b)(2) above); provided, however, that, if a Participant still holding an
outstanding but unexercised NSO or SAR ten (10) years from the date of grant (or, in the case of an NSO or SAR with a maximum term of less than ten (10) years, such maximum term) is prohibited by applicable law or a written policy of the
Company applicable to similarly situated employees from engaging in any open-market sales of Stock, and if at such time the Stock is publicly traded (as determined by the Administrator), the maximum term of such Award will instead be deemed to
expire on the thirtieth (30th) day following the date the Participant is no longer prohibited from engaging in such open market sales. 

7. EFFECT OF CERTAIN TRANSACTIONS 
  

 
 (a) Mergers, etc. Except as
otherwise provided in an Award agreement, the following provisions will apply in the event of a Covered Transaction: 
 (1) Assumption or
Substitution. If the Covered Transaction is one in which there is an acquiring or surviving entity, the Administrator may (but, for the avoidance of doubt, need not) provide (i) for the assumption or continuation of some or all
outstanding Awards or any portion thereof or (ii) for the grant of new awards in substitution therefor by the acquiror or survivor or an affiliate of the acquiror or survivor. 

(2) Cash-Out of Awards. Subject to Section 7(a)(5) below, the Administrator may (but,
for the avoidance of doubt, need not) provide for payment (a “cash-out”), with respect to some or all Awards or any portion thereof, equal in the case of each affected Award or portion
thereof to the excess, if any, of (A) the Fair Market Value of one share of 

  
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Stock (as determined by the Administrator in its reasonable discretion) times the number of shares of Stock subject to the Award or such portion, over (B) the aggregate exercise or purchase
price, if any, under the Award or such portion (in the case of an SAR, the aggregate base value above which appreciation is measured), in each case on such payment terms (which need not be the same as the terms of payment to holders of Stock) and
other terms, and subject to such conditions, as the Administrator determines, it being understood that if the exercise or purchase price (or base value) of an Award is equal to or greater than the Fair Market Value of one share of Stock (as
determined in accordance with this Section 7(a)(2)), the Award may be cancelled with no payment due hereunder. 
 (3) Acceleration of
Certain Awards. Subject to Section 7(a)(7) below, the Administrator may (but, for the avoidance of doubt, need not) provide that any Award requiring exercise will become exercisable, in full or in part and/or that the delivery of any
shares of Stock remaining deliverable under any outstanding Award of Stock Units (including Restricted Stock Units and Performance Awards to the extent consisting of Stock Units) will be accelerated in full or in part, in each case on a basis that
gives the holder of the Award a reasonable opportunity, as determined by the Administrator, following exercise of the Award or the delivery of the shares, as the case may be, to participate as a stockholder in the Covered Transaction. 

(4) Change in Control. Notwithstanding anything herein to the contrary, unless otherwise expressly provided for in the Award agreement or
another contract, including an employment or severance agreement or severance plan, or under the terms of a transaction constituting a Change in Control, in the event of a Change in Control, each outstanding Award will fully vest (which, in the case
of Performance Awards shall be to their maximal value) and become exercisable immediately prior to the consummation of such Change in Control, and the Administrator shall notify the Participant in writing or electronically that the Award will be
fully vested and exercisable for a period of at least fifteen (15) days from the date of such notice, (which notice may be delivered prior to the consummation of the Change in Control) and the Award will terminate upon the expiration of such
period if not otherwise assumed or substituted pursuant to Section 7(a)(1) above or cashed-out pursuant to Section 7(a)(2) above. 

(5) Termination of Awards Upon Consummation of Covered Transaction. Except as the Administrator may otherwise determine in any case and except
for the 15-day exercise period set forth above in Section 7(a)(4), each Award will automatically terminate (and in the case of outstanding shares of Restricted Stock, will automatically be
forfeited) upon consummation of the Covered Transaction, other than Awards assumed pursuant to Section 7(a)(1) above. 
 (6) Additional
Limitations. Any share of Stock and any cash or other property delivered pursuant to Section 7(a)(2) or Section 7(a)(3) above with respect to an Award may, in the discretion of the Administrator, contain such restrictions, if any,
as the Administrator deems appropriate to reflect any performance or other vesting conditions to which the Award was subject and that did not lapse (and were not satisfied) in connection with the Covered Transaction. For purposes of the immediately
preceding sentence, a cash-out under Section 7(a)(2) above or acceleration under Section 7(a)(3) above will not, in and of itself, be treated as the lapsing (or satisfaction) of a
performance or other vesting condition. In the case of Restricted Stock that does not vest and is not forfeited in connection with the Covered Transaction, the Administrator may require that any amounts delivered, exchanged or otherwise paid in
respect of such Stock in connection with the Covered Transaction be placed in escrow or otherwise made subject to such restrictions as the Administrator deems appropriate to carry out the intent of the Plan. 

(b) Changes in and Distributions With Respect to Stock. 

(1) Basic Adjustment Provisions. In the event of a stock dividend, stock split or combination of shares (including a reverse stock split),
recapitalization, reclassification or other distribution of the Company’s equity securities without the receipt of consideration by the Company, or other change in the Company’s capital structure that constitutes an equity restructuring
within the meaning of FASB ASC 718, the Administrator will make appropriate adjustments to the maximum number of shares specified in Section 4(a) that may be delivered under the Plan and will also make appropriate adjustments to the number and
kind of shares of stock or securities subject to Awards then outstanding or subsequently granted, any exercise or purchase prices (or base values) relating to Awards and any other provision of Awards affected by such change. 

(2) Certain Other Adjustments. The Administrator may also make adjustments of the type described in Section 7(b)(1) above to take
into account distributions to stockholders other than those provided for in Section 7(a) and 7(b)(1), or any other event, if the Administrator determines that adjustments are appropriate to avoid distortion in the operation of the Plan, having
due regard for the qualification of ISOs under Section 422 and the requirements of Section 409A, where applicable. 
 (3) Continuing
Application of Plan Terms. References in the Plan to shares of Stock will be construed to include any stock or securities resulting from an adjustment pursuant to this Section 7. 

  
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 8. LEGAL CONDITIONS ON DELIVERY OF STOCK 

 
  

The Company will not be obligated to deliver any shares of Stock pursuant to the Plan or to remove any restriction from shares of Stock previously delivered
under the Plan until: (i) the Company is satisfied that all legal matters in connection with the issuance and delivery of such shares have been addressed and resolved; (ii) if the outstanding Stock is at the time of delivery listed on any
stock exchange or national market system, the shares to be delivered have been listed or authorized to be listed on such exchange or system upon official notice of issuance; and (iii) all conditions of the Award have been satisfied or waived.
The Company may require, as a condition to exercise of the Award, such representations or agreements as counsel for the Company may consider appropriate to avoid violation of the Securities Act of 1933, as amended, or any applicable state or non-U.S. securities law. Any Stock required to be issued to Participants under the Plan will be evidenced in such manner as the Administrator may deem appropriate, including book-entry registration or
delivery of stock certificates. In the event that the Administrator determines that Stock certificates will be issued to Participants under the Plan, the Administrator may require that certificates evidencing Stock issued under the Plan bear an
appropriate legend reflecting any restriction on transfer applicable to such Stock, and the Company may hold the certificates pending lapse of the applicable restrictions. 

9. AMENDMENT AND TERMINATION 
  

 
 The Administrator may at any time or times amend the
Plan or any outstanding Award for any purpose which may at the time be permitted by law, and may at any time terminate the Plan as to any future grants of Awards; provided, that except as otherwise expressly provided in the Plan the Administrator
may not, without the Participant’s consent, alter the terms of an Award so as to affect materially and adversely the Participant’s rights under the Award, unless the Administrator expressly reserved the right to do so at the time the Award
was granted or unless the Administrator determines in its sole discretion and prior to the date of any Covered Transaction that such amendment or alteration either (i) is required or advisable in order for the Company, the Plan or the Award to
satisfy any law or regulation or to meet the requirements of or avoid adverse financial accounting consequences under any accounting standard, or (ii) is not reasonably likely to significantly diminish the benefits provided under such Award, or
that any such diminishment has been adequately compensated. Any amendments to the Plan will be conditioned upon stockholder approval only to the extent, if any, such approval is required by law (including the Code and applicable stock exchange
requirements), as determined by the Administrator. 
 10. OTHER COMPENSATION ARRANGEMENTS 

 
  

The existence of the Plan or the grant of any Award will not in any way affect the Company’s right to Award a person bonuses or other compensation in
addition to Awards under the Plan. 
 11. MISCELLANEOUS 
  

 
 (a) Waiver of Jury Trial. By
accepting an Award under the Plan, each Participant waives any right to a trial by jury in any action, proceeding or counterclaim concerning any rights under the Plan and any Award, or under any amendment, waiver, consent, instrument, document or
other agreement delivered or which in the future may be delivered in connection therewith, and agrees that any such action, proceedings or counterclaim will be tried before a court and not before a jury. By accepting an Award under the Plan, each
Participant certifies that no officer, representative, or attorney of the Company has represented, expressly or otherwise, that the Company would not, in the event of any action, proceeding or counterclaim, seek to enforce the foregoing waivers.
Notwithstanding anything to the contrary in the Plan, nothing herein is to be construed as limiting the ability of the Company and a Participant to agree to submit disputes arising under the terms of the Plan or any Award made hereunder to binding
arbitration or as limiting the ability of the Company to require any eligible individual to agree to submit such disputes to binding arbitration as a condition of receiving an Award hereunder. 

(b) Limitation of Liability. Notwithstanding anything to the contrary in the Plan, neither the Company, nor any Affiliate, nor the
Administrator, nor any person acting on behalf of the Company, any Affiliate, or the Administrator, will be liable to any Participant or to the estate or beneficiary of any Participant or to any other holder of an Award by reason of any acceleration
of income, or any additional tax (including any interest and penalties), asserted by reason of the failure of an Award to satisfy the requirements of Section 422 or Section 409A or by reason of Section 4999 of the Code, or otherwise
asserted with respect to the Award. 

  
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 12. ESTABLISHMENT OF SUB-PLANS 

The Administrator may from time to time establish one or more sub-plans under the Plan for purposes of
satisfying applicable blue sky, securities or tax laws of various jurisdictions. The Administrator will establish such sub-plans by adopting supplements to the Plan setting forth (i) such
limitations on the Administrator’s discretion under the Plan as it deems necessary or desirable and (ii) such additional terms and conditions not otherwise inconsistent with the Plan as it deems necessary or desirable. All supplements so
established will be deemed to be part of the Plan, but each supplement will apply only to Participants within the affected jurisdiction (as determined by the Administrator). 

13. GOVERNING LAW 
  

 
 The laws of the State of Delaware will govern all
questions concerning the construction, validity and interpretation of this Plan, without regard to that state’s conflict of laws rules. 

  
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 EXHIBIT A 

Definition of Terms 
  

 
 The following terms, when used in the Plan, will have
the meanings and be subject to the provisions set forth below: 
 “Administrator”: The Compensation Committee,
except that the Compensation Committee may delegate (i) to one or more of its members (or one or more other members of the Board (including the full Board)) such of its duties, powers and responsibilities as it may determine; (ii) to one
or more officers of the Company the power to grant Awards to the extent permitted by Section 157(c) of the Delaware General Corporation Law; and (iii) to such Employees or other persons as it determines such ministerial tasks as it deems
appropriate. In the event of any delegation described in the preceding sentence, the term “Administrator” will include the person or persons so delegated to the extent of such delegation. 

“Affiliate”: Any corporation or other entity that stands in a relationship to the Company that would result in the
Company and such corporation or other entity being treated as one employer under Section 414(b) and Section 414(c) of the Code. 

“Award”: Any or a combination of the following: 

(i) Stock Options. 
 (ii) SARs. 

(iii) Restricted Stock. 
 (iv) Unrestricted Stock. 

(v) Stock Units, including Restricted Stock Units. 
 (vi)
Performance Awards. 
 (vii) Cash Awards. 
 (viii) Awards
(other than Awards described in (i) through (vii) above) that are convertible into or otherwise based on Stock. 

“Board”: The Board of Directors of the Company. 

“Cash Award”: An Award denominated in cash. 

“Cause”: In the case of any Participant who is party to an employment or severance-benefit agreement that contains
a definition of “Cause,” the definition set forth in such agreement will apply with respect to such Participant under the Plan for so long as such agreement is in effect. In the case of any other Participant, “Cause” will mean,
as determined by the Administrator in its reasonable judgment, (i) a substantial failure of the Participant to perform the Participant’s duties and responsibilities to the Company or subsidiaries or substantial negligence in the
performance of such duties and responsibilities; (ii) the commission by the Participant of a felony or a crime involving moral turpitude; (iii) the commission by the Participant of theft, fraud, embezzlement, material breach of trust or
any material act of dishonesty involving the Company or any of its subsidiaries; (iv) a significant violation by the Participant of the code of conduct of the Company or its subsidiaries of any material policy of the Company or its
subsidiaries, or of any statutory or common law duty of loyalty to the Company or its subsidiaries; (v) material breach of any of the terms of the Plan or any Award made under the Plan, or of the terms of any other agreement between the Company
or subsidiaries and the Participant; or (vi) other conduct by the Participant that could be expected to be harmful to the business, interests or reputation of the Company. 

“Change in Control”: The first to occur of (i) a “person,” as such term is used in Sections 13(d)
and 14(d) of the Exchange Act (other than the Company or one of its subsidiaries or an employee benefit plan of the Company or any of its subsidiaries, including any trustee of such plan acting as trustee) becoming the “beneficial owner”
(as defined in 

  
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Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing fifty percent (50%) or more of the
combined voting power of the Company’s then outstanding securities entitled to vote generally in the election of directors; (ii) a consummation of (x) a merger or consolidation of the Company with any other corporation, other than a
merger or consolidation that would result in the voting securities of the Company outstanding immediately prior thereto continuing to represent (either by remaining outstanding or by being converted into voting securities of the surviving entity)
more than fifty percent (50%) of the total voting power represented by the voting securities of the Company or such surviving entity outstanding immediately after such merger or consolidation, or (y) the sale or disposition by the Company
of all or substantially all the Company’s assets; or (iii) a change in the composition of the Board, as a result of which fewer than a majority of the directors are Incumbent Directors. “Incumbent Directors” shall mean directors
who either (A) are directors of the Company as of the date the Plan is approved by the stockholders, or (B) are elected, or nominated for election, to the Board with the affirmative votes of at least a majority of the Incumbent Directors
at the time of such election or nomination (but shall not include an individual whose election or nomination is in connection with an actual or threatened proxy contest relating to the election of directors to the Company). For the avoidance of
doubt, a transaction will not constitute a Change in Control if: (i) its sole purpose is to change the jurisdiction of the Company’s incorporation, or (ii) its sole purpose is to create a holding company that will be owned in
substantially the same proportions by the persons who held the Company’s securities immediately before such transaction. 

“Code”: The U.S. Internal Revenue Code of 1986 as from time to time amended and in effect, or any successor statute
as from time to time in effect. 
 “Compensation Committee”: The Compensation Committee of the Board. 

“Company”: Arrowhead Pharmaceuticals, Inc. 

“Covered Transaction”: Any of (i) a consolidation, merger, or similar transaction or series of related
transactions, including a sale or other disposition of stock, in which the Company is not the surviving corporation or which results in the acquisition of all or substantially all of the Company’s then outstanding common stock by a single
person or entity or by a group of persons and/or entities acting in concert; (ii) a sale or transfer of all or substantially all the Company’s assets; or (iii) a dissolution or liquidation of the Company. Where a Covered Transaction
involves a tender offer that is reasonably expected to be followed by a merger described in clause (i) (as determined by the Administrator), the Covered Transaction will be deemed to have occurred upon consummation of the tender offer. 

“Date of Adoption”: The earlier of the date the Plan was approved by the Company’s stockholders or adopted by
the Board, as determined by the Compensation Committee. 
 “Employee”: Any person who is employed by the Company
or an Affiliate. 
 “Employment”: A Participant’s employment or other service relationship with the Company and its
Affiliates. Employment will be deemed to continue, unless the Administrator expressly provides otherwise, so long as the Participant is employed by, or otherwise is providing services in a capacity described in Section 5 to the Company or an
Affiliate. If a Participant’s employment or other service relationship is with an Affiliate and that entity ceases to be an Affiliate, the Participant’s Employment will be deemed to have terminated when the entity ceases to be an Affiliate
unless the Participant transfers Employment to the Company or its remaining Affiliates. Notwithstanding the foregoing and the definition of “Affiliate” above, in construing the provisions of any Award relating to the payment of
“nonqualified deferred compensation” (subject to Section 409A) upon a termination or cessation of Employment, references to termination or cessation of employment, separation from service, retirement or similar or correlative terms
will be construed to require a “separation from service” (as that term is defined in Section 1.409A-1(h) of the Treasury Regulations, after giving effect to the presumptions contained
therein) from the Company and from all other corporations and trades or businesses, if any, that would be treated as a single “service recipient” with the Company
under Section 1.409A-1(h)(3) of the Treasury Regulations. The Company may, but need not, elect in writing, subject to the applicable limitations under Section 409A, any of the special
elective rules prescribed in Section 1.409A-1(h) of the Treasury Regulations for purposes of determining whether a “separation from service” has occurred. Any such written election
will be deemed a part of the Plan. 
 “Exchange Act”: The Securities Exchange Act of 1934, as amended. 

“Fair Market Value”: As of any date, the value of the Stock determined as follows: 

 

	(i)	 If the Stock is listed on any established stock exchange or traded on any established market, the Fair Market
Value of a share of Stock as of any date of determination will be, unless otherwise determined by the Board, the closing sales price for such stock as quoted on such exchange or market (or the exchange or market with the greatest volume of trading
in the Stock) on the date of determination, as reported in a source the Board deems reliable. 



  
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	(ii)	 Unless otherwise provided by the Board, if there is no closing sales price for the Stock on the date of
determination, then the Fair Market Value will be the closing selling price on the last preceding date for which such quotation exists. 


  

	(iii)	 In the absence of such markets for the Stock, the Fair Market Value will be determined by the Board in good
faith and in a manner that complies with Sections 409A and 422 of the Code. 


 “ISO”: A Stock
Option intended to be an “incentive stock option” within the meaning of Section 422. Each Stock Option granted pursuant to the Plan will be treated as providing by its terms that it is to be an NSO unless, as of the date of grant, it
is expressly designated as an ISO. 
 “NSO”: A Stock Option that is not intended to be an “incentive stock
option” within the meaning of Section 422. 
 “Participant”: A person who is granted an Award under the
Plan. 
 “Performance Award”: An Award subject to Performance Criteria. 

“Performance Criteria”: Specified criteria, other than the mere continuation of Employment or the mere passage of
time, the satisfaction of which is a condition for the grant, exercisability, vesting or full enjoyment of an Award. Such criteria may include, without limitation, a measure of performance relating to any or any combination of the following
(measured either absolutely or by reference to an index or indices and determined either on a consolidated basis or, as the context permits, on a divisional, subsidiary, line of business, project or geographical basis or in combinations thereof):
sales; revenues; assets; expenses; earnings before or after deduction for all or any portion of interest, taxes, depreciation, or amortization, whether or not on a continuing operations or an aggregate or per share basis; return on equity,
investment, capital or assets; one or more operating ratios; borrowing levels, leverage ratios or credit rating; market share; capital expenditures; cash flow; stock price; stockholder return; sales of particular products or services; customer
acquisition or retention; acquisitions and divestitures (in whole or in part); joint ventures and strategic alliances; spin-offs, split-ups and the like; reorganizations; or recapitalizations,
restructurings, financings (issuance of debt or equity) or refinancings. A Performance Criterion and any targets with respect thereto determined by the Administrator need not be based upon an increase, a positive or improved result or avoidance of
loss. 
 “Plan”: The Arrowhead Pharmaceuticals, Inc. 2021 Incentive Plan as from time to time amended and in
effect. 
 “Prior Plan”: The Arrowhead Research Corporation 2013 Incentive Plan. 

“Restricted Stock”: Stock subject to restrictions requiring that it be redelivered or offered for sale to the
Company if specified conditions are not satisfied. 
 “Restricted Stock Unit”: A Stock Unit that is, or as to
which the delivery of Stock or cash in lieu of Stock is, subject to the satisfaction of specified performance or other vesting conditions. 

“SAR”: A right entitling the holder upon exercise to receive an amount (payable in cash and/or in shares of Stock
of equivalent value) equal to the excess of the Fair Market Value of the shares of Stock subject to the right over the base value from which appreciation under the SAR is to be measured. 

“Section 409A”: Section 409A of the Code. 

“Section 422”: Section 422 of the Code. 

“Stock”: Common stock of the Company, par value $0.001 per share. 

“Stock Option”: An option entitling the holder to acquire shares of Stock upon payment of the exercise price. 

“Stock Unit”: An unfunded and unsecured promise, denominated in shares of Stock, to deliver Stock or cash measured
by the value of Stock in the future. 

  
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 “Unrestricted Stock”: Stock not subject to any restrictions under
the terms of the Award. 

  
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