What changed in this filing

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Item 5. Other Information

2025-08-07 compared with 2025-05-12 · 15 added, 48 removed, 28 unchanged (69% of the section changed)

OTHER INFORMATION

(a) Severance and Change of Control Agreements

The Company entered into Severance and Change of Control Agreements with each of Daniel Apel and James Hamilton on May 8, 2025 and each of Christopher Anzalone and Patrick O’Brien on May 9, 2025 (the “Severance Agreements”).

Under the Severance Agreements, upon a termination of the executive’s employment by the Company without “Cause” (and not as a result of the executive’s death or disability) or due to the executive’s “Resignation for Good Reason” (each quoted term as defined in each Severance Agreement), the Company will provide the following severance benefits:

(i) payment of accrued but unpaid base salary, accrued but unused vacation, and any annual cash bonus earned but unpaid for the preceding fiscal year;

(ii) a lump sum severance payment equal to six months’ worth of the executive’s base salary (or, for Dr.

Anzalone, 12 months’ worth of his base salary, plus a pro-rated portion of his target annual cash bonus for the year in which the termination occurs) (the “Severance Payment”);

and (iii) reimbursement of health care continuation premiums for the 12-month period (or, for Dr.

Anzalone, the 18-month period) following the termination date.

If the termination of employment described above occurs within the period beginning three months prior to the signing of a definitive agreement that would result in a “Change of Control” (as defined in each Severance Agreement) through the first anniversary of such Change of Control, the Company will provide the following severance benefits in lieu of the benefits described above:

(i) payment of accrued but unpaid base salary, accrued but unused vacation, and any annual cash bonus earned but unpaid for the preceding fiscal year;

(ii) a lump sum severance payment equal to (a) 12 months’ worth (or, for Dr.

Anzalone, 24 months’ worth) of the executive’s base salary, plus (b) one and one-half times (or, for Dr.

Anzalone, two times) the executive’s target annual cash bonus for the year in which the termination occurs (the “COC Severance Payment”);

provided, however, that if the executive has received a Severance Payment, the COC Severance Payment shall be reduced by the amount of such Severance Payment;

(iii) reimbursement of health care continuation premiums for the 18-month period following the termination date;

and (iv) accelerated vesting of all outstanding equity awards, with any performance-based vesting criteria deemed achieved at the target level of performance (and, if the termination occurs within the permitted period prior to the Change of Control, a lump sum cash payment equal to the value of any equity awards that would have vested had the executive remained employed through the Change of

The severance benefits provided under the Severance Agreements are subject to each executive’s execution and non-revocation of a release of claims in favor of the Company and its affiliates.

Further, in the event that any payments or benefits provided under the Severance Agreements or otherwise constitute “parachute payments” within the meaning of Section 280G of the Internal Revenue Code of 1986, as amended (the “Code”), the executive will receive the portion of such payments and benefits that results in the greatest after-tax benefit to the executive (including after payment of any excise tax under Section 4999 of the Code).

CFO Retirement Letter

As previously announced, Ken Myszkowski is expected to retire as Chief Financial Officer of the Company, effective as of May 13, 2025 (the “Effective Date”).

In connection therewith, on May 9, 2025, the Company entered into a transition agreement with Mr.

Myszkowski (the “CFO Retirement Letter”).

Under the CFO Retirement Letter, Mr.

Myszkowski will remain an employee of the Company following the Effective Date through January 31, 2026 (the “Transition Period”) to be reasonably available for consultation at the request of his successor, Mr.

Apel, and to assist Mr.

Apel with certain regulatory filings.

In consideration for his services, Mr.

Myszkowski will receive a base salary at an annualized rate of $200,000 through the end of the Transition Period, subject to his continued employment.

If the Company terminates Mr.

Myszkowski’s employment without cause prior to the end of the Transition Period, Mr.

Myszkowski will receive (i) a lump sum payment equal to three months’ worth of his annualized base salary and (ii) an amount equal to the cost of three months of healthcare insurance.

The foregoing descriptions of the Severance Agreements and the CFO Retirement Letter are not complete and are qualified in their entirety by reference to the full texts of the Severance Agreements and the CFO Retirement Letter, copies of which are filed as Exhibits 10.1, 10.2, 10.3, 10.4 and 10.5 to this Quarterly Report on Form 10-Q and are incorporated herein by reference.

During the quarter ended March 31, 2025, no director or officer (as defined in Exchange Act Rule 16a-1(f)) adopted or terminated trading plans intended to satisfy Rule 10b5-1(c), except as set forth in the following table:

Name Title Adoption or Termination Date Plan Start Date Plan End Date Shares

Ken Myszkowski Chief Financial Officer Terminated on 1/6/2025

6/11/2024 2/28/2025 n/a 115,000

Ken Myszkowski Chief Financial Officer 1/7/2025 4/10/2025 12/31/2025 n/a 170,599

James Hamilton Chief Medical Officer, Head of R&D 2/24/2025 5/28/2025 11/30/2026 n/a 60,000

Christopher Anzalone Chief Executive Officer Terminated on 3/12/2025

12/4/2024 12/31/2026 2,082,892 n/a

(1) This column indicates the total number of shares vesting in connection with equity awards, not the number of shares to be sold.

The actual number of shares to be sold will be a smaller number based on whatever is required to satisfy payment of applicable withholding taxes under sell-to-cover arrangements.

During the quarter ended June 30, 2025, no director or officer (as defined in Exchange Act Rule 16a-1(f)) adopted or terminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement.

Number Document Description

3 unchanged sentences

Second Amended and Restated Bylaws of Arrowhead Pharmaceuticals, Inc., as amended January 24, 2023 (incorporated by reference from Exhibit 3.3 of the Company’s Form 10-Q filed on May 2, 2023)

Severance and Change of Control Agreement by and between Company and Christopher Anzalone, dated May 9 , 2025

Severance and Change of Control Agreement by and between Company and Daniel Apel, dated May 8 , 2025

Severance and Change of Control Agreement by and between Company and Patrick O'Brien, dated May 9 , 2025

Severance and Change of Control Agreement by and between Company and James Hamilton, dated May 8 , 2025

CF O Retirement Letter by and between Company and Ken Myszkowski , dated May 9 , 2025

Severance and Change of Control Agreement by and between Company and Christopher Anzalone, dated May 9, 2025 (incorporated by reference from Exhibit 10.1 of the Company’s Form 10-Q filed on May 12, 2025)

Severance and Change of Control Agreement by and between Company and Daniel Apel, dated May 8, 2025 (incorporated by reference from Exhibit 10.

2 of the Company’s Form 10-Q filed on May 12, 2025)

Severance and Change of Control Agreement by and between Company and Patrick O'Brien, dated May 9, 2025 (incorporated by reference from Exhibit 10.

3 of the Company’s Form 10-Q filed on May 12, 2025)

Severance and Change of Control Agreement by and between Company and James Hamilton, dated May 8, 2025 (incorporated by reference from Exhibit 10.

4 of the Company’s Form 10-Q filed on May 12, 2025)

CFO Retirement Letter by and between Company and Ken Myszkowski, dated May 9, 2025 (incorporated by reference from Exhibit 10.

5 of the Company’s Form 10-Q filed on May 12, 2025)

Amendment No.

1 2 to Lease Agreement by and between Arrowhead Madison, Inc.

and University Research Park, dated June 1 1 , 202 5

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

16 unchanged sentences

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.

August 7, 2025

ARROWHEAD PHARMACEUTICALS, INC.

/s/ Kenneth A.

/s/ Daniel Apel

Chief Financial Officer

1 unchanged sentence

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-Q

Item 5. Other Information