[Form 4] Blueprint Medicines Corporation Insider Trading Activity

Rhea-AI Filing Summary

Form 4 discloses that Chief Scientific Officer Percy H. Carter no longer holds Blueprint Medicines (BPMC) equity following the 17 July 2025 closing of the company’s merger with Sanofi. Under the Agreement and Plan of Merger, Sanofi’s subsidiary paid $129.00 in cash plus one contingent value right (CVR) for each BPMC share.

Equity conversions at the merger’s effective time ("Effective Time"):

• Common stock: 21,353 performance-based PSUs were deemed earned (code A) and 56,614 shares were tendered (code D). Remaining 17,894 shares were also converted, leaving 0 shares beneficially owned.
• Equity awards: 128,700 stock options (exercise prices $43.15-$96.57) were fully vested, cancelled and exchanged for the cash/CVR package.
• All outstanding RSUs and the cash-settled portions of 2025 PSUs/RSUs/options will continue to vest in cash & CVRs as specified in the merger agreement.

The filing confirms mechanical settlement of insider holdings and signals completion of Sanofi’s acquisition, with Blueprint Medicines now an indirect wholly owned Sanofi subsidiary.

Positive

• Merger consummation at $129 per share plus CVR confirms acquisition premium payment.
• All unvested awards accelerated, eliminating uncertainty around insider equity obligations.

Negative

• No remaining insider ownership indicates BPMC common stock will be retired, ending public-market participation for investors.

Insights

Equity Compensation Analyst

TL;DR All insider equity cancelled or tendered at $129 + CVR, confirming Sanofi’s takeover completion; no residual BPMC float for this officer.

The report is procedural but material. It verifies that the tender offer and back-end merger closed on 17 Jul 2025, triggering accelerated vesting of PSUs/RSUs and options (total options cancelled: 128,700). Cash consideration exceeds recent pre-offer trading ranges, validating deal premium. From a governance view, Carter’s exit position removes potential insider overhang. For investors, the main takeaway is that BPMC equity now converts to a cash/CVR instrument; equity trading in BPMC should cease once merger processing completes. Impact: neutral to slightly positive—deal completion was expected and already priced in.

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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X

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

1. Name and Address of Reporting Person^*

Carter Percy H.

(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 Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
07/17/2025

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	07/17/2025		A(1)(2)		21,353	A	(3)	74,508	D
Common Stock	07/17/2025		D(1)(2)		56,614	D	(3)(4)(5)	17,894	D
Common Stock	07/17/2025		U(1)(2)		17,894	D	(5)	0	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
Stock Option (Right to Buy)	$89.16	07/17/2025		D(1)(2)			39,200	(6)	(6)	Common Stock	39,200	(6)	0	D
Stock Option (Right to Buy)	$61.31	07/17/2025		D(1)(2)			17,500	(6)	(6)	Common Stock	17,500	(6)	0	D
Stock Option (Right to Buy)	$43.15	07/17/2025		D(1)(2)			25,000	(6)	(6)	Common Stock	25,000	(6)	0	D
Stock Option (Right to Buy)	$95.12	07/17/2025		D(1)(2)			25,000	(6)	(6)	Common Stock	25,000	(6)	0	D
Stock Option (Right to Buy)	$96.57	07/17/2025		D(1)(2)			22,000	(6)	(6)	Common Stock	22,000	(6)	0	D

Explanation of Responses:

1. This Form 4 reports securities transacted pursuant to the Agreement and Plan of Merger (the "Merger Agreement") by and among the Issuer, SANOFI, a French societe anonyme ("Parent"), Aventis Inc., a Pennsylvania corporation and wholly owned subsidiary of Parent ("Aventis"), and Rothko Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Aventis ("Purchaser").

2. Pursuant to the Merger Agreement, Purchaser completed a tender offer to acquire all of the issued and outstanding shares of common stock of the Issuer, par value $0.001 per share (the "Common Stock"), for (i) $129.00 per share, without interest (the "Cash Offer Price"), plus (ii) one (1) contractual contingent value right per share, representing the right to receive contingent payments in cash, without interest, upon the achievement of certain milestones (each a "CVR" and together with the Cash Offer Price, the "Offer Consideration"). On July 17, 2025 (the "Effective Time"), Purchaser merged with and into the Issuer, with the Issuer surviving as an indirect wholly owned subsidiary of Parent.

3. Represents shares previously granted to the Reporting Person subject to performance-based vesting conditions ("PSUs"), for which the performance conditions associated with such PSUs had not yet occurred. As of the Effective Time, each PSU was deemed earned based on the greater of target and actual performance as of the Effective Time. Pursuant to the terms of the Merger Agreement, at the Effective Time, each PSU was cancelled and automatically converted into the right to receive the Offer Consideration, except that fifty percent of such PSUs that were issued in calendar year 2025 were converted into cash-based awards subject to continued vesting as described in the Merger Agreement based on the Cash Offer Price, plus one CVR for each share underlying such portion of the award.

4. Pursuant to the terms of the Merger Agreement, at the Effective Time, each outstanding restricted stock unit ("RSU"), whether vested or unvested, was cancelled and automatically converted into the right to receive the Offer Consideration, except that fifty percent of such RSUs that were issued in calendar year 2025 were converted into cash-based awards subject to continued vesting as described in the Merger Agreement based on the Cash Offer Price, plus one CVR for each share underlying such portion of the award.

5. Pursuant to the terms of the Merger Agreement, at the Effective Time, 824 shares of Common Stock held by the Reporting Person were cancelled and automatically converted into the right to receive the Offer Consideration, and the remaining 17,894 shares of Common Stock held by the Reporting Person were tendered in exchange for the Offer Consideration.

6. Pursuant to the terms of the Merger Agreement, at the Effective Time, each stock option that was outstanding, whether vested or unvested, immediately prior to the Effective Time became fully vested and was cancelled and converted into the right to receive for each share subject to such stock option (i) the Cash Offer Price (less the applicable exercise price per share subject to such option) and (ii) one (1) CVR (in each case, without interest and less applicable tax withholdings), except that fifty percent of such options that were issued in calendar year 2025 were converted into cash-based awards subject to continued vesting as described in the Merger Agreement based on the Cash Offer Price (less the applicable exercise price per share subject to such option), plus one CVR for each share underlying such portion of the option.

	/s/ Melissa Masse, Attorney-in-Fact	07/21/2025
	** 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

What price did Sanofi pay for Blueprint Medicines (BPMC)?

Sanofi paid $129.00 in cash per share plus one CVR for each BPMC share.

When did the Blueprint Medicines–Sanofi merger close?

The merger became effective on 17 July 2025.

How many Blueprint Medicines shares did CSO Percy Carter tender?

The Form 4 shows 56,614 shares disposed and the remaining 17,894 shares converted, resulting in 0 shares held.

What happened to outstanding stock options?

128,700 options vested immediately, were cancelled, and exchanged for cash equal to $129 minus exercise price plus one CVR per underlying share.

Does the insider still own any BPMC stock?

No. After the transactions, the reporting person holds no shares of BPMC common stock.

What is the contingent value right (CVR)?

Each CVR entitles the holder to future cash payments if specified development and regulatory milestones are achieved (details in the merger agreement).