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

390 Madison Avenue 6th Floor New York NY 10017

9096 860754.48 63525838 11/27/2024 NASDAQ Common Stock 11/01/2019 Restricted Stock Grant Issuer N 9096 11/01/2019 Cash Y The shares represented on this filing were acquired during 11/01/19 - 3/01/22. 11/27/2024 08/27/2024 /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for Christina Rossi