X0306 4 2021-02-16 0 0001654151 Deciphera Pharmaceuticals, Inc. DCPH 0001713712 Flynn Daniel Lee C/O DECIPHERA PHARMACEUTICALS, INC. 200 SMITH STREET WALTHAM MA 02451 0 1 0 0 Chief Scientific Officer Common Stock 2021-02-16 4 S 0 508 48.87 D 6532 D Common Stock 2021-02-16 4 A 0 11100 0.00 A 17632 D Common Stock 230435 I By Daniel L. Flynn Revocable Trust Common Stock 91020 I By Daniel L. Flynn Irrevocable Trust Stock Option (Right to Buy) 47.79 2021-02-16 4 A 0 49900 0.00 A 2031-02-15 Common Stock 49900 49900 D The sale was to cover tax liabilities in the vesting of restricted stock. Excludes 230,435 shares previously owned directly by the reporting person which were contributed to the Daniel L. Flynn Revocable Trust on January 15, 2021. The reporting person was awarded 11,100 Restricted Stock Units. Each Restricted Stock Unit represents a contingent right to receive one share of the Issuer's Common Stock. The Restricted Stock Units shall vest in equal 25% installments on February 15, 2022, February 15, 2023, February 15, 2024 and February 15, 2025. The Restricted Stock Units may be settled only by delivering shares of the Issuer's Common Stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance. This stock option was issued pursuant to the Issuer's 2017 Stock Option and Incentive Plan. The option shall vest in equal monthly installments over four years, beginning on March 16, 2021. /s/ Thomas P. Kelly, Attorney-in-Fact 2021-02-18