X0508 4 2025-12-29 0 0000879407 ARROWHEAD PHARMACEUTICALS, INC. ARWR 0001423029 Anzalone Christopher Richard 177 E. COLORADO BLVD SUITE 700 PASADENA CA 91105 1 1 0 0 Chief Executive Officer 1 Common Stock 2025-12-29 4 M 0 35181 6.15 A 3841107 D Common Stock 2025-12-29 4 M 0 16545 6.15 A 3857652 D Common Stock 2025-12-29 4 S 0 35181 69.33 D 3822471 D Common Stock 2025-12-29 4 S 0 16545 68.69 D 3805926 D Stock Option (right to buy Common Stock) 6.15 2025-12-29 4 M 0 35181 0 D 2016-01-01 2026-01-01 Common Stock 35181 16545 D Stock Option (right to buy Common Stock) 6.15 2025-12-29 4 M 0 16545 0 D 2016-01-01 2026-01-01 Common Stock 16545 0 D Includes previously reported shares of common stock underlying Restricted Stock Units granted to the Reporting person, a portion of which are still subject to certain vesting conditions. The exercise of non-qualified stock options and sale was made as the stock options were approaching their expiration date. The shares were sold pursuant to a 10b5-1 trading plan adopted by the Reporting Person in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The price reported on Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $69.09 to $69.62, inclusive. The reporting person undertakes to provide to Arrowhead Pharmaceuticals, Inc., any security holder of Arrowhead Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote of this Form 4. The price reported on Column 4 is the weighted average price. These shares were sold in multiple transactions at prices ranging from $68.10 to $69.08, inclusive. The reporting person undertakes to provide to Arrowhead Pharmaceuticals, Inc., any security holder of Arrowhead Pharmaceuticals, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote of this Form 4. All options were fully vested and exercisable as of January 1, 2016. /s/Christopher Anzalone 2025-12-30