| Item 1. | |
| (a) | Name of issuer:
Blueprint Medicines Corp |
| (b) | Address of issuer's principal executive offices:
45 Sidney Street, Cambridge, Massachusetts 02139 |
| Item 2. | |
| (a) | Name of person filing:
This Statement is filed by each of the entities and persons listed below, all of whom together are referred to herein as the "Reporting Persons":
(i) M.H. Davidson & Co., a New York limited partnership ("CO"). M.H. Davidson & Co. GP, L.L.C., a Delaware limited liability company ("CO GP"), is the general partner of CO and Davidson Kempner Liquid GP Topco LLC, a Delaware limited liability company, is the managing member of CO GP. DKCM (as defined below) is responsible for the voting and investment decisions of CO;
(ii) Davidson Kempner Arbitrage, Equities and Relative Value LP, a Cayman Islands exempted limited partnership ("DKAERV"). Davidson Kempner Multi-Strategy GP II LLC, a Delaware limited liability company ("DKAERV GP"), is the general partner of DKAERV and Davidson Kempner Liquid GP Topco LLC, a Delaware limited liability company, is the managing member of DKAERV GP. DKCM is responsible for the voting and investment decisions of DKAERV;
(iii) Davidson Kempner Capital Management LP, a Delaware limited partnership and a registered investment adviser with the U.S. Securities and Exchange Commission, acts as investment manager to a certain managed account (the "Managed Account") and each of CO and DKAERV ("DKCM"). DKCM GP LLC, a Delaware limited liability company, is the general partner of DKCM. The managing members of DKCM are Anthony A. Yoseloff, Conor Bastable, Shulamit Leviant, Morgan P. Blackwell, Patrick W. Dennis, Gabriel T. Schwartz, Zachary Z. Altschuler, Joshua D. Morris, Suzanne K. Gibbons, Gregory S. Feldman, Melanie Levine and James Li; and
Anthony A. Yoseloff, through DKCM, is responsible for the voting and investment decisions relating to the common stock, par value $0.001 per share ("Common Stock") of Blueprint Medicines Corporation (the "Company") that were held by the Managed Account, CO and DKAERV. |
| (b) | Address or principal business office or, if none, residence:
The address of the principal business office of each of the Reporting Persons is c/o Davidson Kempner Capital Management LP, 9 West 57th Street, 29th Floor, New York, NY 10019. |
| (c) | Citizenship:
(i) CO - a New York limited partnership
(ii) DKAERV - a Cayman Islands exempted limited partnership
(iii) DKCM - a Delaware limited partnership
(iv) Anthony A. Yoseloff - United States |
| (d) | Title of class of securities:
Common Stock, par value $0.001 per share |
| (e) | CUSIP No.:
09627Y109 |
| Item 3. | If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a: |
| (a) |  Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
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| (b) | Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
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| (c) | Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
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| (d) | Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
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| (e) | An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
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| (f) | An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
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| (g) | A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
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| (h) | A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
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| (i) | A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
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| (j) | A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
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| (k) | Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
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| Item 4. | Ownership |
| (a) | Amount beneficially owned:
The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
As of the date of the event which requires the filing of this Schedule 13G, the Reporting Persons may have been deemed to beneficially own more than 5% of the shares of Common Stock outstanding. |
| (b) | Percent of class:
0% |
| (c) | Number of shares as to which the person has:
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| | (i) Sole power to vote or to direct the vote:
The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
|
| | (ii) Shared power to vote or to direct the vote:
The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
|
| | (iii) Sole power to dispose or to direct the disposition of:
The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
|
| | (iv) Shared power to dispose or to direct the disposition of:
The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
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| Item 5. | Ownership of 5 Percent or Less of a Class. |
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Ownership of 5 percent or less of a class
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| Item 6. | Ownership of more than 5 Percent on Behalf of Another Person. |
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Not Applicable
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| Item 7. | Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person. |
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Not Applicable
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| Item 8. | Identification and Classification of Members of the Group. |
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Not Applicable
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| Item 9. | Notice of Dissolution of Group. |
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Not Applicable
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