STOCK PURCHASE AGREEMENT THIS STOCK PURCHASE AGREEMENT (this “Agreement”) is entered into as of November 25, 2024, by and among Arrowhead Pharmaceuticals, Inc., a Delaware corporation (the “Company”), and Sarepta Therapeutics Investments, Inc., a...

STOCK PURCHASE AGREEMENT THIS STOCK PURCHASE AGREEMENT (this “Agreement”) is entered into as of November 25, 2024, by and among Arrowhead Pharmaceuticals, Inc., a Delaware corporation (the “Company”), and Sarepta Therapeutics Investments, Inc., a Delaware corporation (“Purchaser” and, together with the Company, the “Parties”). RECITALS WHEREAS, the Company desires to issue and sell to Purchaser common stock, par value $0.0001 per share, of the Company (the “Common Stock”) for an aggregate purchase price of $325,000,000; and WHEREAS, the Company and Purchaser are executing and delivering this Agreement in reliance upon the exemption from securities registration afforded by Section 4(a)(2) of the Securities Act. NOW, THEREFORE, in consideration of the mutual agreements, representations, warranties, covenants and conditions set forth in this Agreement, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows: 1. PURCHASE AND SALE 1.1 Sale and Issuance of the Shares. In reliance upon the representations, warranties and covenants set forth herein, and subject to the terms and conditions set forth in this Agreement, the Company shall issue and sell to Purchaser, and Purchaser shall purchase from the Company, 11,926,301 shares of Common Stock (the “Shares”) at a purchase price per share equal to $27.2507. In the event of any stock dividend, stock split, combination of shares, recapitalization or other similar change in the capital structure of the Company after the date hereof and on or prior to the Closing that affects or relates to the Common Stock, the number of Shares to be issued to Purchaser pursuant to this Agreement shall be adjusted proportionately. 1.2 Closing. (a) The purchase and sale of the Shares shall take place remotely at 10:00 a.m. (Pacific Time) on the Effective Date, as defined in that certain Exclusive License and Collaboration Agreement, dated as of November 25, 2024, by and between Purchaser and the Company (the “Collaboration Agreement”), or at such other time as the Company and Purchaser shall mutually agree (which time, date and place are referred to in this Agreement as the “Closing”). At the Closing, the Company shall instruct Computershare Trust Company (the “Transfer Agent”) to register the issuance of the Shares (as defined below) via book entry, free and clear of all restrictive and other legends (except as expressly provided in Section 3.3(c)), against delivery to the Company by Purchaser at the Closing of $325,000,000.00, payable in immediately available funds by wire transfer to an account or accounts designated by the Company.

11 licenses, certificates, approvals, authorizations, permits and supplements or amendments thereto required by any such Applicable Laws and/or for the ownership of its properties or the conduct of its business as it relates to a Company Product and as described in the SEC Filings (collectively, “Authorizations”) and such Authorizations are valid and in full force and effect and the Company is not in violation of any term of any such Authorizations; (iii) the Company has not received any written notice of adverse finding, warning letter or other written correspondence or notice from the U.S. Food and Drug Administration (the “FDA”) or any other Governmental Authority alleging or asserting noncompliance with any Applicable Laws or Authorizations relating to a Company Product; (iv) the Company has not received written notice of any ongoing claim, action, suit, proceeding, hearing, enforcement, investigation, arbitration or other action from any Governmental Authority or third party alleging that any Company Product, operation or activity related to a Company Product is in violation of any Applicable Laws or Authorizations or has any knowledge that any such Governmental Authority or third party is considering any such claim, litigation, arbitration, action, suit, investigation or proceeding, nor, to the Company’s knowledge, has there been any material noncompliance with or violation of any Applicable Laws by the Company that would reasonably be expected to require the issuance of any such written notice or result in an investigation, corrective action, or enforcement action by the FDA or similar Governmental Authority with respect to a Company Product; (v) the Company has not received written notice that any Governmental Authority has taken, is taking or intends to take action to limit, suspend, modify or revoke any Authorizations or has any knowledge that any such Governmental Authority has threatened or is considering such action with respect to a Company Product; and (vi) the Company has filed, obtained, maintained or submitted all material reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments as required by any Applicable Laws or Authorizations and that all such reports, documents, forms, notices, applications, records, claims, submissions and supplements or amendments were complete, correct and not misleading on the date filed (or were corrected or supplemented by a subsequent submission). (b) Except as set forth in the SEC Disclosure, to the Company’s knowledge, neither the Company nor any of its directors, officers, employees or agents, has made, or caused the making of, any false statements on, or material omissions from, any other records or documentation prepared or maintained to comply with the requirements of the FDA or any other Governmental Authority. (c) Except as set forth in the SEC Disclosure, the clinical studies and tests conducted by the Company or on behalf of the Company, have been and, if still pending, are being conducted in all material respects pursuant to all Applicable Laws and Authorizations; the descriptions of the results of such clinical studies and tests contained in the SEC Filings are accurate and complete in all material respects and fairly present the data derived from such clinical studies and tests; the Company is not aware of any clinical studies or tests, the results of which the Company believes reasonably call into question the research, nonclinical or clinical study or test results described or referred to in the SEC Filings when viewed in the context in which such results are described; and the Company has not received any written notices or correspondence from any

15 (c) Purchaser acknowledges and agrees that the Shares are being offered in a transaction not involving any public offering within the meaning of the Securities Act, and Purchaser understands that the Shares have not been registered under the Securities Act, by reason of their issuance by the Company in a transaction exempt from the registration requirements of the Securities Act, and that the Shares must continue to be held and may not be offered, resold, transferred, pledged or otherwise disposed of by Purchaser unless a subsequent disposition thereof is registered under the Securities Act or is exempt from such registration and in each case in accordance with any applicable securities laws of any state of the United States. Purchaser understands that the exemptions from registration afforded by Rule 144 (the provisions of which are known to it) promulgated under the Securities Act depend on the satisfaction of various conditions including, but not limited to, the time and manner of sale, the holding period and on requirements relating to the Company which are outside of Purchaser’s control and which the Company may not be able to satisfy, and that, if applicable, Rule 144 may afford the basis for sales only in limited amounts. Purchaser acknowledges and agrees that it has been advised to consult legal counsel prior to making any offer, resale, transfer, pledge or disposition of any of the Shares. Purchaser acknowledges that no federal or state agency has passed upon or endorsed the merits of the offering of the Shares or made any findings or determination as to the fairness of this investment. (d) Purchaser understands that any certificates or book entry notations evidencing the Shares may bear the following legend: “THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), OR THE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES. THE SECURITIES HAVE BEEN ACQUIRED FOR INVESTMENT AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED UNLESS (I) SUCH SECURITIES HAVE BEEN REGISTERED FOR SALE PURSUANT TO THE SECURITIES ACT, (II) SUCH SECURITIES MAY BE SOLD PURSUANT TO RULE 144, (III) THE COMPANY HAS RECEIVED AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO IT THAT SUCH TRANSFER MAY LAWFULLY BE MADE WITHOUT REGISTRATION UNDER THE SECURITIES ACT, OR (IV) THE SECURITIES ARE TRANSFERRED WITHOUT CONSIDERATION TO AN AFFILIATE OF SUCH HOLDER OR A CUSTODIAL NOMINEE (WHICH FOR THE AVOIDANCE OF DOUBT SHALL REQUIRE NEITHER CONSENT NOR THE DELIVERY OF AN OPINION).” (e) Purchaser acknowledges and agrees that it can bear the economic risk and complete loss of its investment in the Shares and has such knowledge and experience in financial or business matters that it is capable of evaluating the merits and risks of the investment in the Shares. (f) Purchaser is not relying and has not relied on any representations or warranties whatsoever regarding the subject matter of this Agreement, express or

21 (f) knowingly assist, knowingly induce or knowingly encourage any other Person to take any action of the type referred to in clause “(a)”, “(b)”, “(c)”, “(d)” or “(e)” of this sentence; (g) enter into any discussions, negotiations, arrangement or agreement with any other Person relating to any of the foregoing; or (h) publicly request or publicly propose that the Company amend, waive or consider the amendment or waiver of any provision set forth in this Section 6.3. Notwithstanding the foregoing, it is understood and agreed that Purchaser shall not be prohibited from entering into an agreement and having discussions with legal, accounting or financial advisors for the limited purposes of evaluating any of the transactions contemplated by this Section 6.3, and Purchaser may initiate private discussions with, and submit proposals confidentially to, the Chief Executive Officer of the Company or the Board of Directors of the Company regarding a transaction otherwise prohibited by this Section 6.3; provided, however, that any such proposal shall be expressly conditioned on approval of the Board of Directors and shall not reasonably be expected to require public disclosure. 6.4 Antitrust Filings. Each of the Company and Purchaser, or their respective Affiliates, as applicable, shall make any required HSR Filing as promptly as practicable, but not later than ten (10) Business Days after the date hereof, in the case of the HSR Filing, in accordance with applicable Laws. In furtherance of the foregoing, the Company and Purchaser agree to: (a) keep the other parties apprised of the status of matters relating to the completion of the Antitrust Filings; (b) reasonably cooperate in the process to obtain antitrust clearance by the Outside Date; (c) furnish promptly to government agencies or authorities of competent jurisdiction any information required and reasonably requested under the Merger Control Laws; (d) furnish to another party or its counsel all information within its possession that is reasonably required for any Antitrust Filings to be made by such party in connection with the transactions contemplated by this Agreement or, as applicable, the Collaboration Agreement; (e) promptly notify the other parties of any communications from or with any government agency or authority of competent jurisdiction to the extent relating to any Antitrust Filing or the transactions contemplated by this Agreement or, as applicable, the Collaboration Agreement; (f) consult with the other parties in advance of participating in any meeting or substantive discussion with any government agency or authority relating to

22 the Antitrust Filings, and, to the extent permitted by such government agency or authority, give the other parties the opportunity to attend and participate thereat; and (g) consult and cooperate with the other parties in connection with all analyses, appearances, presentations, memoranda, briefs, arguments, opinions and proposals made or submitted to any Governmental Authority in connection with proceedings under or relating to the Antitrust Filings. “Antitrust Filing” means filings that may be required by the Company and Purchaser, or their respective Affiliates, with the United States Federal Trade Commission and the Antitrust Division of the United States Department of Justice of a Notification and Report Form for Certain Mergers and Acquisitions (as that term is defined in the HSR Act) with respect to the transactions to occur under this Agreement and/or the Collaboration Agreement, together with all required documentary attachments thereto (collectively, an “HSR Filing”), and any equivalent filings with foreign governmental authorities that may be required and advisable under any Merger Control Laws. “Business Day” means any day except Saturday, Sunday and any legal holiday or a day on which banking institutions in Cambridge, Massachusetts or Pasadena, California generally are authorized or required by law or other governmental actions to close. “Merger Control Laws” means all United States and foreign national, federal, state, and local laws, statutes, ordinances, rules, regulations, orders, treaties and decrees (“Laws”) relating to antitrust or competition matters, or that are designed or intended to prohibit, restrict or regulate actions having the purpose or effect of monopolization or restraint of trade or lessening of competition. 6.5 Securities Laws Disclosure; Publicity. The Company shall, by 9:00 a.m. (New York City time) on or before the fourth Business Day following the date hereof, issue a press release disclosing the material terms of the transactions contemplated hereby, and shall, within four Business Days following the date hereof, file a Current Report on Form 8-K disclosing the material terms of the transactions contemplated hereby and including this a copy of the Company’s press release described in this paragraph as an exhibit thereto. The Company and Purchaser shall consult with each other regarding the substance of any public disclosure by either party regarding this Agreement and regarding the issuance of any other press releases with respect to the transactions contemplated hereby, and neither the Company nor Purchaser shall issue any such press release nor otherwise make any such public statement without the prior consent of the Company, with respect to any press release of Purchaser, or without the prior consent of Purchaser, with respect to any press release of the Company, which consent shall not unreasonably be withheld or delayed, except if such disclosure is required by law, rule or regulation, in which case the disclosing party shall promptly provide the other party with prior notice of such public statement or communication. 6.6 Book Entry Statement. The Company hereby agrees to deliver to Purchaser a book entry statement from the Transfer Agent showing the Shares registered in the name of Purchaser within three Business Days of the Closing.

24 (d) by either Purchaser or the Company in the event that any court of competent jurisdiction or Governmental Authority shall have issued an order, decree or ruling or taken any other action restraining, enjoining or otherwise prohibiting the actions contemplated hereby and such order, decree, ruling or other action shall have become final and non-appealable. 7.2 Effect of Termination. In the event of any termination of this Agreement as provided in Section 7.1, this Agreement shall forthwith become wholly void and of no further force and effect; provided that nothing herein shall relieve any party from liability for willful breach of this Agreement. 8. GENERAL 8.1 Successors and Assigns. Except as otherwise provided herein, the terms and conditions of this Agreement shall inure to the benefit of and be binding upon the respective successors and permitted assigns of the parties (including any permitted transferees of any Shares). Purchaser and the Company may not assign their respective rights or obligations under this Agreement, in whole or in part, except with the consent of the other party; provided, however, the rights and obligations of Purchaser may be assigned, without the prior written consent of the Company, to one or more of Purchaser’s Affiliates. Any attempted assignment made in contravention of this Agreement shall be null and void and of no force or effect. 8.2 Entire Agreement. This Agreement and the documents, schedules and exhibits referred to herein or therein constitute the entire agreement between the parties and supersede all prior communications, representations, understandings and agreements of the parties with respect to the subject matter hereof and thereof. No party shall be liable or bound to any other party in any manner by any warranties, representations or covenants except as specifically set forth herein or therein. All schedules and exhibits hereto are hereby incorporated herein by reference. Nothing in this Agreement, express or implied, is intended to confer upon any third party any rights, remedies, obligations or liabilities under or by reason of this Agreement, except as expressly provided in this Agreement. 8.3 General Interpretation; Defined Terms. The terms of this Agreement have been negotiated by the parties hereto and the language used in this Agreement shall be deemed to be the language chosen by the parties hereto to express their mutual intent. This Agreement shall be construed without regard to any presumption or rule requiring construction against the party causing such instrument or any portion thereof to be drafted, or in favor of the party receiving a particular benefit under this Agreement. No rule of strict construction will be applied against any Person. 8.4 Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without regard to the principles of conflicts of law thereof. 8.5 Jurisdiction. The parties hereby irrevocably and unconditionally submit to the jurisdiction of the United States District Court for the Southern District of New York for the purpose of any suit, action or other proceeding arising out of or based upon this Agreement.

25 8.6 Counterparts. This Agreement may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement, and may be delivered to the other parties hereto by facsimile. 8.7 Section Headings and References. The section headings contained herein are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. When a reference is made in this Agreement to a Section or Exhibit, such reference is to a Section or Exhibit of or to this Agreement unless otherwise indicated. The words “hereof,” “herein,” “hereto” and “hereunder” and words of similar import, when used in this Agreement, shall refer to this Agreement as a whole and not to any particular provision of this Agreement. The terms defined in the singular has a comparable meaning when used in the plural, and vice versa. References to a Person are also to its successors and permitted assigns. References to an agreement are to such agreement as amended, restated, modified or otherwise supplemented, from time to time. The term “dollars” and “$” means United States dollars. The word “including” means “including without limitation” and the words “include” and “includes” have corresponding meanings. 8.8 Severability. If any term of provision of this Agreement is determined to be illegal, unenforceable or invalid in whole or in part for any reason, such illegal, unenforceable or invalid provisions or party thereof shall be stricken from this Agreement, and such provision shall not affect the legality, enforceability or validity of the remainder of this Agreement. If any provision or part thereof of this Agreement is stricken in accordance with the provisions of this Section 8.8, then such stricken provision shall be replaced, to extent possible, with a legal, enforceable and valid provision that is as similar in tenor to the stricken provision as is legally possible. 8.9 Notices. All notices and other communications given or made pursuant hereto will be in writing and will be deemed to have been duly given on the date delivered, if delivered personally, or on the next Business Day after being sent by reputable overnight courier (with delivery tracking provided, signature required, and delivery prepaid), in each case, to the Parties at the following addresses, or on the date sent and confirmed by confirmatory return email to the email address specified below or at such other address, or email address for a Party as will be specified by notice given in accordance with this Section 8.9. If to the Company: Arrowhead Pharmaceuticals, Inc. 000 X. Xxxxxxxx Xxxx., Xxxxx 000 Xxxxxxxx, XX 00000 Attention: General Counsel Email: Xxxxxxx.Xxxxxxx@xxxxxxxxxxxxxxx.xxx With a copy to: Xxxxxx, Xxxx & Xxxxxxxx LLP One Embarcadero Center, Suite 2600

[Signature Page to Stock Purchase Agreement] IN WITNESS WHEREOF, the undersigned parties have duly executed this Common Stock Purchase Agreement effective as of the date first above written. COMPANY: ARROWHEAD PHARMACEUTICALS, INC. By: /s/ Xxxxxxxxxxx Xxxxxxxx, PhD Name: Xxxxxxxxxxx Xxxxxxxx, PhD Title: President and Chief Executive Officer PURCHASER: SAREPTA THERAPEUTICS INVESTMENTS, INC. By: /s/ Xxxxxx Xxxxxxx Name: Xxxxxx Xxxxxxx Title: President

Exhibit A Investor Rights Agreement

INVESTOR RIGHTS AGREEMENT This Investor Rights Agreement (this “Agreement”) is made and entered into as of [], 2024, by and between Arrowhead Pharmaceuticals, Inc., a Delaware corporation (the “Company”), and Sarepta Therapeutics Investments, Inc., a Delaware corporation (the “Purchaser”). NOW, THEREFORE, IN CONSIDERATION of the mutual covenants contained in this Agreement, and for other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, the Company and the Purchaser agree as follows: DEFINITIONS Definitions. As used in this Agreement, the following terms shall have the following meanings: (a) “Additional Registration Statement” has the meaning set forth in Section 3.1.1(c). (b) “Adverse Disclosure” means public disclosure of material non-public information that, in the good faith judgment of the board of directors of the Company: (i) would be required to be made in such Registration Statement filed with the SEC by the Company so that such Registration Statement, from and after its effective date, does not contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading; (ii) would not be required to be made at such time but for the filing, effectiveness or continued use of such Registration Statement; and (iii) the Company has a bona fide business purpose for not disclosing publicly. (c) “Affiliate” means, with respect to any Person, another Person that controls, is controlled by or is under common control with such Person; provided, that with respect to the Purchaser, the term “Affiliate” shall not include any employee benefit plan of Purchaser. A Person shall be deemed to control another Person if such Person possesses, directly or indirectly, the power to direct or cause the direction of the management and policies of such Person, whether through the ownership of voting securities, by contract or otherwise. For the purposes of this Agreement, in no event shall the Purchaser or any of its Affiliates be deemed Affiliates of the Company or any of its Affiliates, nor shall the Company or any of its Affiliates be deemed Affiliates of the Purchaser or any of its Affiliates. (d) “Agreement” has the meaning set forth in the preamble. (e) “Board” means the Board of Directors of the Company. (f) “Board Observer” has the meaning set forth in Section 2.4.

(g) “Board Right Termination Date” means the earlier of (i) the date on which Purchaser, together with its Affiliates, beneficially owns less than 4.99% of the Company’s outstanding Common Stock and (ii) the date on which Xxxx Xxxxxx is no longer an employee of the Purchaser or its Affiliates. (h) “Business Day” means any day except Saturday, Sunday and any legal holiday or a day on which banking institutions in Cambridge, Massachusetts generally are authorized or required by law or other governmental actions to close. (i) “Closing” means the date of the purchase and sale of the Shares and the Pre-Funded Warrant pursuant to the Purchase Agreement. (j) “Collaboration Agreement” means the Exclusive License and Collaboration Agreement by and between the Company and the Purchaser, dated as of [], 2024. (k) “Common Stock” means the common stock of the Company, par value $0.001 per share. (l) “Company Indemnitee” has the meaning set forth in Section 3.8. (m) “Company Registration Statement” has the meaning set forth in Section 3.2.1. (n) “Effectiveness Period” has the meaning set forth in Section 3.1.3. (o) “Exchange Act” means the Securities Exchange Act of 1934, as amended, as in effect from time to time. (p) “Filing Deadline” has the meaning set forth in Section 3.1.1. (q) “FINRA” means the Financial Industry Regulatory Authority. (r) “Holder” or “Holders” means the Purchaser, or such other holder or holders, as the case may be, from time to time of Registrable Securities. (s) “Initial Registration Statement” has the meaning set forth in Section 3.1.1(a). (t) “Issuer Free Writing Prospectus” means an issuer free writing prospectus, as defined in Rule 433 under the Securities Act, relating to an offer of the Registrable Securities. (u) “Laws” mean all United States and foreign national, federal, state, and local laws, statutes, ordinances, rules, regulations, orders, treaties and decrees. (v) “Loss” has the meaning set forth in Section 3.7.1. (w) “New Registration Statement” has the meaning set forth in Section 3.1.1. (x) “Permitted Transferee” means any Affiliate of the Purchaser.

(y) “Person” means any individual, firm, corporation, limited liability company, partnership, company or other entity, and shall include any successor (by merger or otherwise) of such entity. (z) “Pre-Funded Warrant” means any pre-funded warrant to purchase Common Stock issued to the Purchaser pursuant to Section 6.9 of the Purchase Agreement. (aa) “Prospectus” means (i) the prospectus included in any Registration Statement, all amendments and supplements to such prospectus, including post- effective amendments and supplements, and all other material incorporated by reference in such prospectus, and (ii) any Issuer Free Writing Prospectus. (bb) “Public Offering” means the offer and sale of Registrable Securities for cash pursuant to an effective registration statement under the Securities Act (other than a registration statement on Form S-4 or Form S-8 or any successor form). (cc) “Purchase Agreement” means the Stock Purchase Agreement, by and between the Company and the Purchaser, dated as of [], 2024. (dd) “Purchaser” has the meaning set forth in the preamble. (ee) “Registrable Securities” means all of (i) the Shares, (ii) the Warrant Shares, and (iii) any securities issued or issuable upon any stock split, dividend or other distribution, recapitalization or similar event with respect to the foregoing, provided, that with respect to a particular Holder, such Holder’s Shares and Warrant Shares shall cease to be Registrable Securities upon a sale pursuant to a Registration Statement or Rule 144 under the Securities Act (in which case, only such security sold by the Holder shall cease to be a Registrable Security). (ff) “Registration” means registration under the Securities Act of the offer and sale to the public of any Registrable Securities under a Registration Statement. The terms “register”, “registered” and “registering” shall have correlative meanings. (gg) “Registration Expenses” has the meaning set forth in Section 3.6. (hh) “Registration Statement” or “Registration Statements” means any one or more registration statements of the Company filed under the Securities Act that covers the resale of any of the Registrable Securities pursuant to the provisions of this Agreement (including the Initial Registration Statement, the New Registration Statement and, if applicable, any Additional Registration Statement), amendments and supplements to such Registration Statements, including post-effective amendments, all exhibits and all material incorporated by reference or deemed to be incorporated by reference in such Registration Statements. (ii) “Representatives” means, with respect to any Person, any of such Person’s officers, directors, employees, agents, attorneys, accountants, actuaries, consultants, equity financing partners or financial advisors or other Person associated with, or acting on behalf of, such Person.

used diligent efforts to advocate with the SEC for the registration of all or a greater number of Registrable Securities), unless otherwise directed in writing by a Holder as to its Registrable Securities, the number of Registrable Securities to be registered on such Registration Statement will be reduced: first by Registrable Securities not acquired pursuant to the Purchase Agreement (whether pursuant to registration rights or otherwise); second by Registrable Securities represented by the Pre-Funded Warrant; and third by Registrable Securities represented by Xxxxxx. In the event the Company amends the Initial Registration Statement or files a New Registration Statement, as the case may be, under clauses (i) or (ii) above, the Company will use its commercially reasonable efforts to file with the SEC, as promptly as allowed by SEC, one or more registration statements on Form S-3 or such other form available to register for resale those Registrable Securities that were not registered for resale on the Initial Registration Statement, as amended, or the New Registration Statement. As promptly as possible, and in any event within thirty (30) calendar days of the issuance of any Pre-Funded Warrant pursuant to Section 6.9 of the Purchase Agreement, the Company shall file with the SEC a shelf Registration Statement pursuant to Rule 415 under the Securities Act or, if Rule 415 is not available for offers and sales of the Registrable Securities, by such other means of distribution of Registrable Securities as the Holders may reasonably specify (an “Additional Registration Statement”), relating to the offer and sale of Registrable Securities underlying such Pre-Funded Warrant by any Holders thereof from time to time in accordance with the methods of distribution elected by such Holders, and the Company shall use its reasonable best efforts to cause the Additional Registration Statement to promptly become effective under the Securities Act, provided, however, that the Company shall be permitted to file a post-effective amendment or Prospectus supplement to any effective shelf Registration Statement in lieu of filing an Additional Registration Statement to the extent the Company determines, and the Holders agree, that the Registrable Securities may be sold thereunder by the Holders pursuant to their intended plan of distribution. Continued Effectiveness. The Company shall use its reasonable best efforts to keep such Registration Statement continuously effective under the Securities Act in order to permit the Prospectus forming part of the Registration Statement to be usable by Holders until the date as of which no Holder holds Registrable Securities (such period of effectiveness, the “Effectiveness Period”). Subject to Section 3.1.3, the Company shall be deemed not to have used its reasonable best efforts to keep the Registration Statement effective during the Effectiveness Period if the Company voluntarily takes any action or omits to take any action that would result in Holders of the Registrable Securities covered thereby not being able to offer and sell any Registrable Securities pursuant to such Registration Statement during the Effectiveness Period, unless such action or omission is required by applicable law. Suspension of Registration. If the continued use of such Registration Statement at any time would require the Company to make an Adverse Disclosure, the Company may, upon giving prompt written notice of such action to the Holders, suspend use of the Registration Statement (a “Suspension”); provided, however, that the Company shall not be permitted to exercise a Suspension more than one time during any twelve (12)-month period for a period not to exceed sixty (60) days. In the case of a Suspension, the Holders agree to suspend use of the applicable Prospectus in connection with any sale or purchase of, or offer to sell or purchase, Registrable Securities, upon receipt of the notice referred to above. The Company shall

notify the participating Holders and the managing underwriter or underwriters, if any, and (if requested) confirm such notice in writing and provide copies of the relevant documents, as soon as reasonably practicable after notice thereof is received by the Company (a) when the applicable Registration Statement or any amendment thereto has been filed or becomes effective, and when the applicable Prospectus or any amendment or supplement thereto has been filed, (b) of any written comments by the SEC, or any request by the SEC or other federal or state governmental authority for amendments or supplements to such Registration Statement or such Prospectus, or for additional information (whether before or after the effective date of the Registration Statement) or any other correspondence with the SEC relating to, or which may affect, the Registration, (c) of the issuance by the SEC of any stop order suspending the effectiveness of such Registration Statement or any order by the SEC or any other regulatory authority preventing or suspending the use of any preliminary or final Prospectus or the initiation or threatening of any proceedings for such purposes, (d) if, at any time, the representations and warranties of the Company in any applicable underwriting agreement cease to be true and correct in all material respects and (e) of the receipt by the Company of any notification with respect to the suspension of the qualification of the Registrable Securities for offering or sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; promptly notify each selling Holder and the managing underwriter or underwriters, if any, when the Company becomes aware of the happening of any event as a result of which the applicable Registration Statement or the Prospectus included in such Registration Statement contains any untrue statement of a material fact or omits to state a material fact necessary to make the statements therein (in the case of such Prospectus or any preliminary Prospectus, in light of the circumstances under which they were made) not misleading, when any Issuer Free Writing Prospectus includes information that may conflict with the information contained in the Registration Statement, or, if for any other reason it shall be necessary during such time period to amend or supplement such Registration Statement or Prospectus in order to comply with the Securities Act and, as promptly as reasonably practicable thereafter, prepare and file with the SEC, and furnish without charge to the selling Holders and the managing underwriter or underwriters, if any, an amendment or supplement to such Registration Statement or Prospectus, which shall correct such misstatement or omission or effect such compliance; to the extent the Company is eligible under the relevant provisions of Rule 430B under the Securities Act, the Company shall include in the applicable Registration Statement such disclosures as may be required by Rule 430B under the Securities Act (referring to the unnamed selling security holders in a generic manner by identifying the initial offering of the securities to the Holders) in order to ensure that the Holders may be added to such Registration Statement at a later time through the filing of a Prospectus supplement rather than a post-effective amendment; use its reasonable best efforts to prevent, or obtain the withdrawal of, any stop order or other order or notice preventing or suspending the use of any preliminary or final Prospectus; promptly incorporate in a Prospectus supplement, Issuer Free Writing Prospectus or post-effective amendment such information as the managing underwriter or underwriters and the Purchaser agree should be included therein relating to the plan of distribution with respect to such Registrable Securities; and make all required filings of such Prospectus supplement, Issuer Free Writing Prospectus or post-effective amendment as soon as reasonably practicable after being

notified of the matters to be incorporated in such Prospectus supplement, Issuer Free Writing Prospectus or post-effective amendment; furnish to each selling Holder and each underwriter, if any, without charge, as many conformed copies as such Holder or underwriter may reasonably request of the applicable Registration Statement and any amendment or post-effective amendment or supplement thereto, including financial statements and schedules, all documents incorporated therein by reference and all exhibits (including those incorporated by reference); deliver to each selling Holder and each underwriter, if any, without charge, as many copies of the applicable Prospectus (including each preliminary Prospectus) and any amendment or supplement thereto and such other documents as such Holder or underwriter may reasonably request in order to facilitate the disposition of the Registrable Securities by such Holder or underwriter (it being understood that the Company shall consent to the use of such Prospectus or any amendment or supplement thereto by each of the selling Holders and the underwriters, if any, in connection with the offering and sale of the Registrable Securities covered by such Prospectus or any amendment or supplement thereto); on or prior to the date on which the applicable Registration Statement becomes effective, use its reasonable best efforts to register or qualify in connection with the Registration or qualification of such Registrable Securities for offer and sale under the securities or “Blue Sky” laws of each state and other jurisdiction as any such selling Holder or managing underwriter or underwriters, if any, or their respective counsel reasonably request in writing and do any and all other acts or things reasonably necessary or advisable to keep such Registration or qualification in effect for the Effectiveness Period, provided that the Company shall not be required to qualify generally to do business in any jurisdiction where it is not then so qualified or to take any action which would subject it to taxation or general service of process in any such jurisdiction where it is not then so subject; cooperate with the selling Holders and the managing underwriter or underwriters, if any, to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be sold and not bearing any restrictive legends and enable such Registrable Securities to be in such denominations and registered in such names as the managing underwriters may request prior to any sale of Registrable Securities to the underwriters; use its reasonable best efforts to cause the Registrable Securities covered by the applicable Registration Statement to be registered with or approved by such other governmental agencies or authorities as may be necessary to enable the seller or sellers thereof or the underwriter or underwriters, if any, to consummate the disposition of such Registrable Securities; make such representations and warranties to the Holders being registered, and the underwriters or agents, if any, in form, substance and scope as are customarily made by issuers in public offerings similar to the offering then being undertaken; enter into such customary agreements (including underwriting and indemnification agreements) and take all such other actions as the Purchaser or the managing underwriter or underwriters, if any, reasonably request in order to expedite or facilitate the Registration and

disposition of such Registrable Securities; obtain for delivery to the Holders and to the underwriter or underwriters, if any, an opinion or opinions from counsel for the Company dated the most recent effective date of the Registration Statement or, in the event of an Underwritten Public Offering, the date of the closing under the underwriting agreement, in customary form, scope and substance, which opinions shall be reasonably satisfactory to such Holders or underwriters, as the case may be, and their respective counsel; in the case of an Underwritten Public Offering, obtain for delivery to the Company and the managing underwriter or underwriters, with copies to the Holders included in such Registration or sale, a comfort letter from the Company’s independent certified public accountants or independent auditors (and, if necessary, any other independent certified public accountants or independent auditors of any subsidiary of the Company or any business acquired by the Company for which financial statements and financial data are, or are required to be, included in the Registration Statement) in customary form and covering such matters of the type customarily covered by comfort letters as the managing underwriter or underwriters reasonably request, dated the date of execution of the underwriting agreement and brought down to the closing under the underwriting agreement; cooperate with each seller of Registrable Securities and each underwriter, if any, participating in the disposition of such Registrable Securities and their respective counsel in connection with any filings required to be made with FINRA; provide and cause to be maintained a transfer agent and registrar for all Registrable Securities covered by the applicable Registration Statement; use its reasonable best efforts to cause all Registrable Securities covered by the applicable Registration Statement to be listed on each securities exchange on which any of the Company’s equity securities are then listed or quoted and on each inter-dealer quotation system on which any of the Company’s equity securities are then quoted; make available upon reasonable notice at reasonable times and for reasonable periods for inspection by the Purchaser, by any underwriter participating in any disposition to be effected pursuant to such Registration Statement and by any attorney, accountant or other agent retained by the Purchaser or any such underwriter, all pertinent financial and other records and pertinent corporate documents and properties of the Company, and cause all of the Company’s officers, directors and employees and the independent public accountants who have certified its financial statements to make themselves available to discuss the business of the Company and to supply all information reasonably requested by any such Person in connection with such Registration Statement; in the case of an Underwritten Public Offering, cause the senior executive officers of the Company to participate in the customary “road show” presentations that may be reasonably requested by the managing underwriter or underwriters in any such offering and otherwise to facilitate, cooperate with, and participate in each proposed offering contemplated herein and customary selling efforts related thereto;

statement of a material fact in any Registration Statement under which such Registrable Securities were registered or sold under the Securities Act (including any final, preliminary or summary Prospectus contained therein or any amendment thereof or supplement thereto or any documents incorporated by reference therein) or (ii) any omission to state therein a material fact required to be stated therein or necessary to make the statements therein (in the case of a Prospectus or preliminary Prospectus, in light of the circumstances under which they were made) not misleading, in each case to the extent, but only to the extent, that such untrue statement or omission is contained in such selling Holder’s Selling Stockholder Information. In no event shall the liability of any selling Holder hereunder be greater in amount than the dollar amount of the proceeds from the sale of its Registrable Securities in the offering giving rise to such indemnification obligation, net of underwriting discounts and commissions but before expenses, less any amounts paid by such Holder pursuant to Section 3.6.4 and any amounts paid by such Holder as a result of liabilities incurred under the underwriting agreement, if any, related to such sale. Conduct of Indemnification Proceedings. Any Person entitled to indemnification hereunder shall (i) give prompt written notice to the indemnifying party of any claim with respect to which it seeks indemnification (provided that any delay or failure to so notify the indemnifying party shall relieve the indemnifying party of its obligations hereunder only to the extent, if at all, that it forfeits substantive legal rights by reason of such delay or failure) and (ii) permit such indemnifying party to assume the defense of such claim with counsel reasonably satisfactory to the indemnified party; provided, however, that any Person entitled to indemnification hereunder shall have the right to select and employ separate counsel and to participate in the defense of such claim, but the fees and expenses of such counsel shall be at the expense of such Person unless (i) the indemnifying party has agreed in writing to pay such fees or expenses, (ii) the indemnifying party shall have failed to assume the defense of such claim within a reasonable time after receipt of notice of such claim from the Person entitled to indemnification hereunder and employ counsel reasonably satisfactory to such Person, (iii) the indemnified party has reasonably concluded (based upon advice of its counsel) that there may be legal defenses available to it or other indemnified parties that are different from or in addition to those available to the indemnifying party, or (iv) in the reasonable judgment of any such Person (based upon advice of its counsel) a conflict of interest may exist between such Person and the indemnifying party with respect to such claims (in which case, if the Person notifies the indemnifying party in writing that such Person elects to employ separate counsel at the expense of the indemnifying party, the indemnifying party shall not have the right to assume the defense of such claim on behalf of such Person). If the indemnifying party assumes the defense, the indemnifying party shall not have the right to settle such action without the consent of the indemnified party. No indemnifying party shall consent to entry of any judgment or enter into any settlement which does not include as an unconditional term thereof the giving by the claimant or plaintiff to such indemnified party of an unconditional release from all liability in respect to such claim or litigation without the prior written consent of such indemnified party. If such defense is not assumed by the indemnifying party, the indemnifying party will not be subject to any liability for any settlement made without its prior written consent, but such consent may not be unreasonably withheld. It is understood that the indemnifying party or parties shall not, except as specifically set forth in this Section 3.6.3, in connection with any proceeding or related proceedings in the same jurisdiction, be liable for the reasonable fees, disbursements or other charges of more than one separate firm admitted to practice in such jurisdiction at any one time unless (x) the employment of more than one counsel has been authorized in writing by the indemnifying party or parties, (y) an indemnified party has reasonably concluded (based on the

MISCELLANEOUS Termination and Effect of Termination. This Agreement shall terminate upon the date on which no Holder holds any Registrable Securities, except for the provisions of Sections 3.6 and 3.7, which shall survive any such termination. No termination under this Agreement shall relieve any Person of liability for breach or Registration Expenses incurred prior to termination. In the event this Agreement is terminated, each Person entitled to indemnification rights pursuant to Section 3.6 hereof shall retain such indemnification rights with respect to any matter that (i) may be an indemnified liability thereunder and (ii) occurred prior to such termination. Permitted Transferees; Assignment. The rights of a Holder hereunder may be assigned (but only with all related obligations as set forth below) in connection with a Transfer of Registrable Securities to a Permitted Transferee of that Holder. Without prejudice to any other or similar conditions imposed hereunder with respect to any such Transfer, no assignment permitted under the terms of this Section 4.2 will be effective unless the Permitted Transferee to which the assignment is being made, if not a Holder, has delivered to the Company a written acknowledgment and agreement in form and substance reasonably satisfactory to the Company that the Permitted Transferee will be bound by, and will be a party to, this Agreement. A Permitted Transferee to whom rights are transferred pursuant to this Section 4.2 may not again transfer those rights to any other Permitted Transferee, other than as provided in this Section 4.2. The Company may not assign its rights (except by merger or in connection with another entity acquiring all or substantially all of the Company’s assets) or obligations hereunder without the prior written consent of all the Holders of the then outstanding Registrable Securities. Governing Law. This Agreement and all claims or causes of action (whether in tort, contract or otherwise) that may be based upon, arise out of or relate to this Agreement or the negotiation, execution or performance of this Agreement (including any claim or cause of action based upon, arising out of or related to any representation or warranty made in or in connection with this Agreement) shall be governed by and construed in accordance with the Laws of the State of New York, without giving effect to any choice or conflict of law provision or rule (whether of the State of New York or any other jurisdiction) that would cause the application of the Laws of any jurisdiction other than the State of York. Counterparts. This Agreement may be executed in two (2) or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. Counterparts may be delivered via facsimile, electronic mail or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes. Titles and Subtitles. The titles and subtitles used in this Agreement are used for convenience only and are not to be considered in construing or interpreting this Agreement. Notices. All notices and other communications given or made pursuant to this Agreement shall be in writing and shall be deemed effectively given upon the earlier of actual receipt, or (a) personal delivery to the party to be notified, (b) when sent, if sent by electronic mail during normal

business hours of the recipient, and if not sent during normal business hours, then on the recipient’s next Business Day, (c) five (5) days after having been sent by registered or certified mail, return receipt requested, postage prepaid, or (d) one (1) Business Day after deposit with a nationally recognized overnight courier, freight prepaid, specifying next Business Day delivery, with written verification of receipt. All communications shall be sent to the respective parties at their address as set forth on the signature page, or to such e-mail address or address as subsequently modified by written notice given in accordance with this Section 3.6. Waiver. Waiver by the Company or the Purchaser of a breach hereunder by the Purchaser or the Company, respectively, shall not be construed as a waiver of any subsequent breach of the same or any other provision. No delay or omission by a party in exercising or availing itself of any right, power or privilege hereunder shall preclude the later exercise of any such right, power or privilege by such party. No waiver shall be effective unless made in writing with specific reference to the relevant provision(s) of this Agreement and signed by a duly authorized representative of the party granting the waiver. All remedies, either under this Agreement or by law or otherwise afforded to any party, shall be cumulative and not alternative. Amendments. Any term of this Agreement may be amended or terminated only with the written consent of the Company and the Purchaser. Severability. The invalidity or unenforceability of any provision hereof shall in no way affect the validity or enforceability of any other provision. Entire Agreement. This Agreement and the Purchase Agreement constitute the full and entire understanding and agreement between the parties with respect to the subject matter hereof and thereof, and any other written or oral agreement relating to the subject matter hereof or thereof existing among the parties are expressly canceled. Specific Enforcement. The parties hereto agree that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with their specific intent or were otherwise breached. It is accordingly agreed that the parties shall be entitled to an injunction or injunctions to prevent or cure breaches of the provisions of this Agreement and to enforce specifically the terms and provisions hereof, in addition to any other remedy to which they may be entitled by law or equity. Exclusive Jurisdiction; Venue. Each of the parties hereto irrevocably agrees that any legal action or proceeding with respect to this Agreement and the rights and obligations arising hereunder, or for recognition and enforcement of any judgment in respect of this Agreement and the rights and obligations arising hereunder brought by another party hereto or its successors or assigns, shall be brought and determined exclusively in the state and federal courts sitting in the City of New York. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the City of New York, Borough of Manhattan and agrees that it will not bring any action relating to this Agreement or any of the transactions contemplated by this Agreement in any court other than the aforesaid courts. Each of the parties hereto hereby irrevocably waives, and agrees not to assert as a defense, counterclaim or otherwise, in any action or proceeding with respect to this Agreement, (a) any claim that it is not personally subject to the jurisdiction of the above named courts for any reason other than the failure to serve in accordance

IN WITNESS WHEREOF, each of the undersigned has duly executed this Agreement as of the date first above written. Company: ARROWHEAD PHARMACEUTICALS, INC. By: ______________________________ Name: Title: Purchaser: SAREPTA THERAPEUTICS INVESTMENTS, INC. By: ______________________________ Name: Title:

Exhibit B Form of Pre-Funded Warrant

Form of Pre-Funded Warrant THE SECURITIES REPRESENTED HEREBY AND THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933. NO TRANSFER OF THE SECURITIES REPRESENTED HEREBY OR THE SECURITIES ISSUABLE UPON EXERCISE OF THESE SECURITIES MAY BE EFFECTED WITHOUT AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO OR AN OPINION OF COUNSEL IN A FORM SATISFACTORY TO THE COMPANY THAT SUCH REGISTRATION IS NOT REQUIRED UNDER THE SECURITIES ACT OF 1933. PRE-FUNDED COMMON STOCK PURCHASE WARRANT ARROWHEAD PHARMACEUTICALS, INC. Warrant Shares: [●] Issue Date: [] THIS PRE-FUNDED COMMON STOCK PURCHASE WARRANT (the “Warrant”) certifies that, for value received, Sarepta Therapeutics, Inc., a Delaware corporation, or its assigns (the “Holder”) is entitled, upon the terms and subject to the limitations on exercise and the conditions hereinafter set forth, at any time on or after the date hereof (the “Initial Exercise Date”), to subscribe for and purchase from Arrowhead Pharmaceuticals, Inc., a Delaware corporation (the “Company”), up to [●] shares (as subject to adjustment hereunder, the “Warrant Shares”) of Common Stock. The purchase price of one share of Common Stock under this Warrant shall be equal to the Exercise Price, as defined in Section 3(b). Section 1. Definitions. For purposes of this Warrant, the following terms shall have the following meanings: a) “Affiliate” means any Person that, directly or indirectly through one or more intermediaries, controls or is controlled by or is under common control with a Person, as such terms are used in and construed under Rule 405 under the Securities Act. b) “Business Day” means any day except any Saturday, any Sunday, any day which is a federal legal holiday in the United States or any day on which banking institutions in Pasadena, California or Cambridge, Massachusetts are authorized or required by law or other governmental action to close. c) “Commission” means the United States Securities and Exchange Commission. d) “Common Stock Equivalents” means any securities of the Company or the Subsidiaries which would entitle the holder thereof to acquire at any time Common Stock, including, without limitation, any debt, preferred stock, right, option, warrant or other instrument that is at any time convertible into or exercisable or exchangeable for, or otherwise entitles the holder thereof to receive, Common Stock.

e) “Exchange Act” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder. f) “Person” means an individual or corporation, partnership, trust, incorporated or unincorporated association, joint venture, limited liability company, joint stock company, government (or an agency or subdivision thereof) or other entity of any kind. g) “Securities Act” means the Securities Act of 1933, as amended. h) “Stock Purchase Agreement” means that certain Stock Purchase Agreement dated as of []. i) “Trading Day” means a day on which the principal Trading Market is open for trading. j) “Trading Market” means any of the following markets or exchanges on which the Common Stock is listed or quoted for trading on the date in question: the NYSE American, the Nasdaq Capital Market, the Nasdaq Global Market, the Nasdaq Global Select Market or the New York Stock Exchange (or any successors to any of the foregoing). k) “Transfer Agent” means Computershare Trust Company, and any successor transfer agent of the Company. Section 2. Issuance of Securities; Registration of Warrants. The Warrant, as initially issued by the Company, is offered and sold pursuant to the Stock Purchase Agreement. Accordingly, the Warrant and the Warrant Shares are “restricted securities” under Rule 144 promulgated under the Securities Act. The Company shall register ownership of this Warrant, upon records to be maintained by the Company for that purpose (the “Warrant Register”), in the name of the record Holder (which shall include the initial Holder or, as the case may be, any assignee to which this Warrant is permissibly assigned hereunder) from time to time. The Company may deem and treat the registered Holder of this Warrant as the absolute owner hereof for the purpose of any exercise hereof or any distribution to the Holder, and for all other purposes, absent actual notice to the contrary. Section 3. Exercise. a) Exercise of Warrant. Exercise of the purchase rights represented by this Warrant may be made, in whole or in part, at any time or times on or after the Initial Exercise Date by delivery to the Company of a duly executed PDF copy submitted by e-mail (or e-mail attachment) of the Notice of Exercise in the form annexed hereto, and delivered in accordance with the notice requirements set forth in Section 6(g) (the “Notice of Exercise”). Notwithstanding the foregoing, with respect to any Notice of Exercise delivered on or prior to the Initial Exercise Date, the Company agrees to deliver the Warrant Shares subject to such Notice(s) of Exercise by 5:30 p.m. (New York time) on the Initial Exercise Date. Within the earlier of (i) one (1) Trading Day and (ii) the number of Trading Days comprising the Standard Settlement Period (as defined in Section 3(d)(i) herein) following the date of exercise as aforesaid, the Holder shall deliver the aggregate Exercise Price (as defined below) for the Warrant Shares specified in the applicable Notice of Exercise by wire transfer or cashier’s check drawn on a United States bank unless the

trading hours” on a Trading Day) pursuant to Section 3(a) hereof or (iii) the VWAP on the date of the applicable Notice of Exercise if the date of such Notice of Exercise is a Trading Day and such Notice of Exercise is both executed and delivered pursuant to Section 3(a) hereof after the close of “regular trading hours” on such Trading Day; (B) = the Exercise Price of this Warrant, as adjusted hereunder; and (X) = the number of Warrant Shares that would be issuable upon exercise of this Warrant in accordance with the terms of this Warrant if such exercise were by means of a cash exercise rather than a cashless exercise. If Warrant Shares are issued in such a cashless exercise, the parties acknowledge and agree that in accordance with Section 3(a)(9) of the Securities Act, the Warrant Shares shall take on the characteristics of the Warrants being exercised, and for purposes of Rule 144, the holding period of the Warrant Shares being issued may be tacked on to the holding period of this Warrant. The Company agrees not to take any position contrary to this Section 3(c), except to the extent required by change in applicable law, rule or regulation after the date hereof. “Bid Price” means, for any date, the price determined by the first of the following clauses that applies: (a) if the Common Stock is then listed or quoted on a Trading Market, the bid price of the Common Stock for the time in question (or the nearest preceding date) on the Trading Market on which the Common Stock is then listed or quoted as reported by Bloomberg L.P. (based on a Trading Day from 9:30 a.m. (New York City time) to 4:02 p.m. (New York City time)), (b) if OTCQB or OTCQX is not a Trading Market, the volume weighted average price of the Common Stock for such date (or the nearest preceding date) on OTCQB or OTCQX as applicable, (c) if the Common Stock is not then listed or quoted for trading on OTCQB or OTCQX and if prices for the Common Stock are then reported on The Pink Open Market (or a similar organization or agency succeeding to its functions of reporting prices), the most recent bid price per share of the Common Stock so reported, or (d) in all other cases, the fair market value of a share of Common Stock as determined in good faith by the Board of Directors of the Company. “VWAP” means, for any date, the price determined by the first of the following clauses that applies: (a) if the Common Stock is then listed or quoted on a Trading Market, the daily volume weighted average price of the Common Stock for such date (or the nearest preceding date) on the Trading Market on which the Common Stock is then listed or quoted as reported by Bloomberg L.P. (based on a Trading Day from 9:30 a.m. (New York City time) to 4:02 p.m. (New York City time)), (b) if OTCQB or OTCQX is not a Trading Market, the volume weighted average price of the Common Stock for such date (or the nearest preceding date) on OTCQB or OTCQX as applicable, (c) if the Common Stock is not then listed or quoted for trading on OTCQB or OTCQX and if prices for the Common Stock are then reported on The Pink Open Market (or a similar organization or agency succeeding to its functions of reporting prices), the most recent bid price per share of the Common Stock so reported, or (d) in all other cases, the fair market value of a share of Common Stock as determined by the Board of Directors of the Company and reasonably

of this Warrant shall constitute full authority to its officers who are charged with the duty of issuing the necessary Warrant Shares upon the exercise of the purchase rights under this Warrant. The Company will take all such reasonable action as may be necessary to assure that such Warrant Shares may be issued as provided herein without violation of any applicable law or regulation, or of any requirements of the Trading Market upon which the Common Stock may be listed. The Company covenants that all Warrant Shares which may be issued upon the exercise of the purchase rights represented by this Warrant will, upon exercise of the purchase rights represented by this Warrant and payment for such Warrant Shares in accordance herewith, be duly authorized, validly issued, fully paid and nonassessable and free from all taxes, liens and charges created by the Company in respect of the issue thereof (other than taxes in respect of any transfer occurring contemporaneously with such issue). Except and to the extent as waived or consented to by the Holder, the Company shall not by any action, including, without limitation, amending its certificate of incorporation or through any reorganization, transfer of assets, consolidation, merger, dissolution, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such actions as may be necessary or appropriate to protect the rights of Holder as set forth in this Warrant against impairment. Without limiting the generality of the foregoing, the Company will (i) not increase the par value of any Warrant Shares above the amount payable therefor upon such exercise immediately prior to such increase in par value, (ii) take all such action as may be necessary or appropriate in order that the Company may validly and legally issue fully paid and nonassessable Warrant Shares upon the exercise of this Warrant and (iii) use commercially reasonable efforts to obtain all such authorizations, exemptions or consents from any public regulatory body having jurisdiction thereof, as may be, necessary to enable the Company to perform its obligations under this Warrant. Before taking any action which would result in an adjustment in the number of Warrant Shares for which this Warrant is exercisable or in the Exercise Price, the Company shall obtain all such authorizations or exemptions thereof, or consents thereto, as may be necessary from any public regulatory body or bodies having jurisdiction thereof. e) Governing Law. All questions concerning the construction, validity, enforcement and interpretation of this Warrant shall be governed by and construed and enforced in accordance with the internal laws of the State of New York, without regard to the principles of conflicts of law thereof. Each party agrees that all legal proceedings concerning the interpretations, enforcement and defense of the transactions contemplated by this Warrant shall be commenced exclusively in the state and federal courts sitting in the City of New York. Each party hereby irrevocably submits to the exclusive jurisdiction of the state and federal courts sitting in the City of New York, Borough of Manhattan for the adjudication of any dispute hereunder or in connection herewith or with any transaction contemplated hereby or discussed herein, and hereby irrevocably waives, and agrees not to assert in any suit, action or proceeding, any claim that it is not personally subject to the jurisdiction of any such court, that such suit, action or proceeding is improper or is an inconvenient venue for such proceeding. Each party hereby irrevocably waives personal service of process and

consents to process being served in any such suit, action or proceeding by mailing a copy thereof via registered or certified mail or overnight delivery (with evidence of delivery) to such party at the address in effect for notices to it under this Warrant and agrees that such service shall constitute good and sufficient service of process and notice thereof. Nothing contained herein shall be deemed to limit in any way any right to serve process in any other manner permitted by law. If either party shall commence an action, suit or proceeding to enforce any provisions of this Warrant, the prevailing party in such action, suit or proceeding shall be reimbursed by the other party for their reasonable attorneys’ fees and other costs and expenses incurred with the investigation, preparation and prosecution of such action or proceeding. f) Nonwaiver and Expenses. No course of dealing or any delay or failure to exercise any right hereunder on the part of Holder shall operate as a waiver of such right or otherwise prejudice the Holder’s rights, powers or remedies. Without limiting any other provision of this Warrant, if the Company willfully and knowingly fails to comply with any provision of this Warrant, which results in any material damages to the Holder, the Company shall pay to the Holder such amounts as shall be sufficient to cover any costs and expenses including, but not limited to, reasonable attorneys’ fees, including those of appellate proceedings, incurred by the Holder in collecting any amounts due pursuant hereto or in otherwise enforcing any of its rights, powers or remedies hereunder. g) Notices. Any and all notices or other communications or deliveries to be provided by the Holders hereunder including, without limitation, any Notice of Exercise, shall be in writing and delivered personally, by e-mail, or sent by a nationally recognized overnight courier service, addressed to the Company, at Arrowhead Pharmaceuticals, Inc., 000 X. Xxxxxxxx Xxxx., Xxxxx 000, Xxxxxxxx, XX 00000, Attention: General Counsel, e-mail: Xxxxxxx.Xxxxxxx@xxxxxxxxxxxxxxx.xxx, or such other email address or address as the Company may specify for such purposes by notice to the Holders. Any and all notices or other communications or deliveries to be provided by the Company hereunder shall be in writing and delivered personally, by e-mail, or sent by a nationally recognized overnight courier service addressed to each Holder at the e-mail address or address of such Xxxxxx appearing on the books of the Company. Any notice or other communication or deliveries hereunder shall be deemed effectively given upon the earlier of actual receipt, or (a) personal delivery to the party to be notified, (b) when sent, if sent by electronic mail during normal business hours of the recipient, and if not sent during normal business hours, then on the recipient’s next Business Day, (c) five (5) days after having been sent by registered or certified mail, return receipt requested, postage prepaid, or (d) one (1) Business Day after deposit with a nationally recognized overnight courier, freight prepaid, specifying next Business Day delivery, with written verification of receipt. h) Limitation of Liability. No provision hereof, in the absence of any affirmative action by the Holder to exercise this Warrant to purchase Warrant Shares, and no enumeration herein of the rights or privileges of the Holder, shall give rise to any liability of the Holder for the purchase price of any Common Stock or as a stockholder of the Company, whether such liability is asserted by the Company or by creditors of the Company. i) Remedies. The Holder, in addition to being entitled to exercise all rights granted by law,

IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by its officer thereunto duly authorized as of the date first above indicated. ARROWHEAD PHARMACEUTICALS, INC. By: Name: Title:

NOTICE OF EXERCISE TO: ARROWHEAD PHARMACEUTICALS, INC. (1) The undersigned hereby elects to purchase ________ Warrant Shares of the Company pursuant to the terms of the attached Warrant (only if exercised in full), and tenders herewith payment of the exercise price in full, together with all applicable transfer taxes, if any. (2) Payment shall take the form of (check applicable box): ☐ in lawful money of the United States; or ☐ if permitted the cancellation of such number of Warrant Shares as is necessary, in accordance with the formula set forth in subsection 3(c), to exercise this Warrant with respect to the maximum number of Warrant Shares purchasable pursuant to the cashless exercise procedure set forth in subsection 3(c). (3) Please issue said Warrant Shares in the name of the undersigned or in such other name as is specified below: The Warrant Shares shall be delivered to the following DWAC Account Number: [SIGNATURE OF HOLDER] Name of Investing Entity: _______________________________________________________________________ Signature of Authorized Signatory of Investing Entity: _________________________________________________ Name of Authorized Signatory: ___________________________________________________________________ Title of Authorized Signatory: ____________________________________________________________________ Date: ____________________________________________________________________________ ____________

ASSIGNMENT FORM (To assign the foregoing Warrant, execute this form and supply required information. Do not use this form to purchase shares.) FOR VALUE RECEIVED, the foregoing Warrant and all rights evidenced thereby are hereby assigned to Name: (Please Print) Address: Phone Number: Email Address: (Please Print) Dated: _______________ __, ______ Holder’s Signature: __________________________ Holder’s Address: ___________________________