X0306 4 2020-05-11 0 0000879407 ARROWHEAD PHARMACEUTICALS, INC. ARWR 0001553338 Waddill William D. 177 E. COLORADO BLVD SUITE 700 PASADENA CA 91105 1 0 0 0 Common Stock 2020-05-11 4 S 0 26000 36.54 D 28000 D The price reported on Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $36.25 to $37.07, 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. /s/William Waddill 2020-05-13