144 0001423029 XXXXXXXX LIVE 0000879407 Arrowhead Pharmaceuticals 001-38042 177 East Colorado Blvd Suite 700 Pasadena CA 91105 6266964702 Christopher Anzalone Officer Common Merrill Lynch

75 Rockefeller Plz 2nd Flr New York NY 10019

130000 8950579.90 135809558 12/15/2025 NASDAQ Common 01/01/2020 Compensation Issuer N 203434 01/01/2020 Compensation Common 01/01/2022 Compensation Issuer N 49761 01/01/2022 Compensation Common 12/20/2022 Compensation Issuer N 46805 12/20/2022 Compensation Y 12/15/2025 Christopher Anzalone