SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Lengauer Christoph (Last) (First) (Middle) C/O BLUEPRINT MEDICINES CORPORATION 38 SIDNEY STREET, SUITE 200 (Street) CAMBRIDGE MA 02139 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 04/29/2015	3. Issuer Name and Ticker or Trading Symbol Blueprint Medicines Corp [ BPMC ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director 10% Owner X Officer (give title below) Other (specify below) Chief Scientific Officer	5. If Amendment, Date of Original Filed (Month/Day/Year) 04/30/2015
			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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	188,332(1)	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	(2)	11/03/2023	Common Stock	35,227(1)	1.485	D
Stock Option (Right to Buy)	(3)	08/14/2024	Common Stock	24,848(1)	1.87	D
Stock Option (Right to Buy)	(4)	02/10/2025	Common Stock	53,408(1)	8.8	D

Explanation of Responses:

1. Table II, column 3 of the Form 3 filed on April 30, 2015 (the "Original Form 3") inadvertently included an aggregate of 24,696 shares underlying stock options, which the Reporting Person had previously exercised. These shares were also inadvertently omitted from Table I, column 2 of the Original Form 3. The Reporting Person previously filed an amendment to the Original Form 3 on May 1, 2015 reporting the beneficial ownership of an aggregate of 188,332 shares of common stock in Table I, including the 24,696 shares omitted from Table I, column 2 of the Original Form 3. This amendment is being filed to reduce the aggregate number of shares underlying derivative securities reported in Table II, column 3 of the Original Form 3 by 24,696 shares. These shares were also inadvertently included in the aggregate number of shares underlying derivative securities reported in Table II, column 9 of a Form 4 filed by the Reporting Person on February 5, 2016.

2. This option vests in 48 equal monthly installments beginning on November 1, 2013.

3. This option vests in 48 equal monthly installments beginning on August 18, 2014.

4. This option vests in 48 equal monthly installments beginning on February 10, 2015.

	/s/ Christine Bellon, Attorney-in-Fact	03/28/2016
	** 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 5 (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).
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