X0306 4 2020-10-09 0 0001654151 Deciphera Pharmaceuticals, Inc. DCPH 0001715153 Bristol James Arthur C/O DECIPHERA PHARMACEUTICALS, INC. 200 SMITH STREET WALTHAM MA 02451 1 0 0 0 Common Stock 2020-10-09 4 M 0 23541 1.89 A 23541 D Common Stock 2020-10-09 4 S 0 19370 53.3532 D 4171 D Common Stock 2020-10-09 4 S 0 3971 54.5281 D 200 D Common Stock 2020-10-09 4 S 0 200 55.43 D 0 D Stock Option (Right to Buy) 1.89 2020-10-09 4 M 0 23541 0.00 D 2025-12-17 Common Stock 23541 0 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 5, 2019. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $53.10 to $54.05, inclusive. The reporting person undertakes to provide to Deciphera Pharmaceuticals, Inc., any security holder of Deciphera 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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $54.13 to $55.12, inclusive. The reporting person undertakes to provide to Deciphera Pharmaceuticals, Inc., any security holder of Deciphera 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. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $55.13 to $55.73, inclusive. The reporting person undertakes to provide to Deciphera Pharmaceuticals, Inc., any security holder of Deciphera 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. This stock option award was issued pursuant to Deciphera Pharmaceuticals, LLC's 2015 Equity Incentive Plan. The option was 100% exercisable on the date of grant, December 18, 2015. /s/ Jeffrey Held, as Attorney-in-Fact 2020-10-13