X0306 4 2020-06-03 0 0001654151 Deciphera Pharmaceuticals, Inc. DCPH 0001348587 Allen Patricia L C/O DECIPHERA PHARMACEUTICALS, INC. 200 SMITH STREET WALTHAM MA 02451 1 0 0 0 Common Stock 2020-06-03 4 M 0 6365 25.73 A 6365 D Common Stock 2020-06-03 4 S 0 6365 59.1437 D 0 D Common Stock 2020-06-05 4 M 0 5635 25.73 A 5635 D Common Stock 2020-06-05 4 S 0 5635 55.9004 D 0 D Stock Option (Right to Buy) 25.73 2020-06-03 4 M 0 6365 0.00 D 2028-05-16 Common Stock 6365 5635 D Stock Option (Right to Buy) 25.73 2020-06-05 4 M 0 5635 0.00 D 2028-05-16 Common Stock 5635 0 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $59.00 to $59.34, 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 $55.09 to $56.00, 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 Issuer's 2017 Stock Option and Incentive Plan and vested in full on May 17, 2019, subject to the Reporting Person's continuous service with the Issuer. /s/ Thomas P. Kelly, Attorney-in-Fact 2020-06-05