X0306 4 2020-12-08 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 Common Stock 2020-12-08 4 M 0 16324 2.01 A 2521561 D Common Stock 2020-12-08 4 S 0 16324 67.97 D 2505237 D Common Stock 2020-12-09 4 M 0 38676 2.01 A 2543913 D Common Stock 2020-12-09 4 S 0 16726 67.27 D 2527187 D Common Stock 2020-12-09 4 S 0 12067 69.80 D 2515120 D Common Stock 2020-12-09 4 S 0 5880 70.87 D 2509240 D Common Stock 2020-12-09 4 S 0 4003 71.61 D 2505237 D Stock Option (right to buy) 2.01 2020-12-08 4 M 0 16324 0.00 D 2013-06-01 2023-05-06 Common Stock 16324 879219 D Stock Option (right to buy) 2.01 2020-12-09 4 M 0 38676 0.00 D 2013-06-01 2023-05-06 Common Stock 38676 840543 D The price reported on Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $67.50 to $68.29, 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 a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.26 to $69.26, 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 a weighted average price. These shares were sold in multiple transactions at prices ranging from $69.27 to $70.25, 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 a weighted average price. These shares were sold in multiple transactions at prices ranging from $70.32 to $71.30, 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 a weighted average price. These shares were sold in multiple transactions at prices ranging from $71.33 to $72.13, 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. Includes a total of 900,000 shares underlying restricted stock units that may be earned based on the achievement of certain performance goals. If the performance goals are not met within the required time periods, the awards will be forfeited in part or in whole. Represents first vesting date. Option vested over four years from date of grant. /s/Christopher Anzalone 2020-12-10