ARROWHEAD PHARMACEUTICALS, INC. 10-Q

ITEM 5. OTHER INFORMATION (c) Trading Plans During the quarter ended December 31, 2025, the following directors and officers (as defined in Exchange Act Rule 16a-1(f)) adopted certain trading plans intended to satisfy Rule 10b5-1(c): Name Title Adoption or Termination Date Plan End Date Shares Vesting and Subject to Sell-To-Cover (1) Other Shares Being Sold (Subject to Certain Conditions) Christopher Anzalone President and Chief Executive Officer 12/22/2025 01/31/2030 1,871,805 n/a James Hamilton Chief Medical Officer, Head of R&D 12/02/2025 03/05/2027 n/a 44,000 (1) This column indicates the total number of shares vesting, but the 10b5-1 Plan provides for the sale of only those shares necessary to satisfy payment of applicable withholding taxes. 40 ITEM 6. EXHIBITS Exhibit Number Document Description 3.1 Amended and Restated Certificate of Incorporation (incorporated by reference from Exhibit 3.3 of the Company’s Form 8-K filed on April 6, 2016) 3.2 Certificate of Amendment to the Amended and Restated Certificate of Incorporation of Arrowhead Pharmaceuticals, Inc. (incorporated by reference from Exhibit 3.2 of the Company’s Form 10-Q filed on May 2, 2023) 3.3* Second Amended and Restated Bylaws of Arrowhead Pharmaceuticals, Inc., as amended January 24, 2023 4.1.*† A mendment No. 2 to Financing Agreement between Arrowhead Pharmaceuticals, Inc. and Sixth Street Lending Partners dated August 7, 2024 31.1* Certification of Chief Executive Officer pursuant to Rule 13a-14(a) of the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 31.2* Certification of Chief Financial Officer pursuant to Rule 13a-14(a) of the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 32.1** Certification of Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 32.2** Certification of Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 101.INS* Inline XBRL Instance Document 101.SCH* Inline XBRL Taxonomy Extension Schema Document 101.CAL* Inline XBRL Taxonomy Extension Calculation Linkbase Document 101.LAB* Inline XBRL Taxonomy Extension Label Linkbase Document 101.PRE* Inline XBRL Taxonomy Extension Presentation Linkbase Document 101.DEF* Inline XBRL Taxonomy Extension Definition Linkbase Document 104* The cover page from this Quarterly Report on Form 10-Q, formatted in Inline XBRL (included as Exhibit 101) _________________ * Filed herewith. ** Furnished herewith. † Certain portions of this exhibit were redacted by means of marking such portions with asterisks because the identified portions are (i) not material and (ii) treated as private or confidential by the Company. 41 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this Quarterly Report on Form 10-Q to be signed on its behalf by the undersigned, thereunto duly authorized. Dated: February 5, 2026 ARROWHEAD PHARMACEUTICALS, INC. By: /s/ Daniel Apel Daniel Apel Chief Financial Officer (Principal Financial Officer and Duly Authorized Officer) 42