X0306 4 2019-03-25 0 0001609351 Spark Therapeutics, Inc. ONCE 0001673526 La Barge Joseph C/O SPARK THERAPEUTICS, INC. 3737 MARKET STREET, SUITE 1300 PHILADELPHIA PA 19104 0 1 0 0 Chief Legal Officer Common Stock 2019-03-25 4 M 0 41755 68.45 A 63237 D Common Stock 2019-03-25 4 F 0 31389 113.42 D 31848 D Common Stock 2019-03-25 4 M 0 33748 40.44 A 65596 D Common Stock 2019-03-25 4 F 0 21260 113.38 D 44336 D Common Stock 2019-03-25 4 M 0 12500 56.17 A 56836 D Common Stock 2019-03-25 4 F 0 8873 113.36 D 47963 D Common Stock 2019-03-25 4 M 0 7000 50.55 A 54963 D Common Stock 2019-03-25 4 F 0 4770 113.36 D 50193 D Common Stock 200 I Held by Reporting Person's immediate family members Stock Option (right to buy) 68.45 2019-03-25 4 M 0 41755 0.00 D 2025-03-15 Common Stock 41755 0 D Stock Option (right to buy) 40.44 2019-03-25 4 M 0 33748 0.00 D 2026-01-04 Common Stock 33748 11250 D Stock Option (right to buy) 56.17 2019-03-25 4 M 0 12500 0.00 D 2027-01-17 Common Stock 12500 12500 D Stock Option (right to buy) 50.55 2019-03-25 4 M 0 7000 0.00 D 2028-01-17 Common Stock 7000 21000 D 25% vested March 16, 2016 and the remainder vested in equal quarterly installments over the following three years. 25% vested January 5, 2017 and the remainder vests in equal quarterly installments over the following three years. 25% vested January 18, 2018 and the remainder vests in equal annual installments over the following three years. 25% vested January 18, 2019 and the remainder vests in equal annual installments over the following three years. /s/ Joseph W. La Barge 2019-03-27