144 0001756941 XXXXXXXX LIVE 0001597264 Blueprint Medicines Corporation 001-37359 45 Sidney Street Cambridge MA 02139 617-374-7580 Christina Rossi Officer Common Stock J.P. Morgan Securities LLC

390 Madison Avenue, 6th Floor New York NY 10017

9096 811363 63906011 03/24/2025 NASDAQ Common Stock 03/01/2022 Restricted Stock Grant Issuer N 9096 03/01/2024 Compensation N Christina Rossi and Gregory Papp

C/o Blueprint Medicines Corporation 45 Sidney Street Cambridge MA 02139

Common Stock 01/21/2025 2274 250457 Christina Rossi and Gregory Papp

C/o Blueprint Medicines Corporation 45 Sidney Street Cambridge MA 02139

Common Stock 02/18/2025 2274 216344 The shares covered by this filing were acquired from restricted stock grants between 03/01/22 and 03/01/24 and will be sold by Christina Rossi and Gregory Papp, jointly. 03/24/2025 08/27/2024 /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Christina Rossi