[Form 4] Blueprint Medicines Corporation Insider Trading Activity

Rhea-AI Filing Summary

Blueprint Medicines Corp. (BPMC) has filed a Form 4 disclosing that Chief Scientific Officer Percy H. Carter sold 1,051 common shares on 07/03/2025 at an average price of $128.25 per share. The transaction was an automatic “sell-to-cover” to satisfy tax-withholding obligations arising from restricted stock unit vesting and was not a discretionary trade. After the sale, Carter’s direct ownership stands at 53,155 shares.

Insights

Securities Analyst

TL;DR Routine, tax-related insider sale; insignificant to BPMC’s float, neutral signal.

The disclosed sale equals roughly 2% of Mr. Carter’s holdings and an immaterial fraction of BPMC’s ~61 million share float. Because the transaction was mandatory to cover withholding taxes from RSU vesting, it does not imply a change in the executive’s outlook. Insider ownership remains substantial at 53,155 shares, preserving alignment with shareholders. The filing therefore carries neutral financial impact.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Rossi Christina

(Last) (First) (Middle)

C/O BLUEPRINT MEDICINES CORPORATION

45 SIDNEY STREET

(Street)

CAMBRIDGE MA 02139

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Blueprint Medicines Corp [ BPMC ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF OPERATING OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
07/03/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	07/03/2025		S(1)		1,172	D	$128.25	63,546	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The sale reported on this Form 4 represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.

	/s/ Melissa Masse, Attorney-in-Fact	07/08/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

How many BPMC shares did the CSO sell on 07/03/2025?

1,051 common shares were sold.

What price did the insider receive for the BPMC shares?

The shares were sold at $128.25 per share.

Why were the BPMC shares sold by the insider?

The sale was an automatic "sell-to-cover" to fund tax-withholding obligations from RSU vesting.

How many BPMC shares does Percy H. Carter still own after the sale?

He now owns 53,155 shares directly.

Does this Form 4 suggest a change in BPMC’s insider sentiment?

The filing appears routine and tax-related; it does not signal a discretionary change in outlook.