Sec Form 13G Filing - Third Rock Ventures II L.P. filing for Blueprint Medicines Corp (BPMC) - 2019-02-13

The remainder of this cover page shall be filled out for a reporting person’s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

NAMES OF REPORTING PERSONS

Third Rock Ventures II, L.P.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    Delaware

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

0

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

878,875

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.0% (1)

TYPE OF REPORTING PERSON

PN

The percent of class was calculated based on 43,950,375 shares of common stock issued and outstanding as of October 26, 2018, as disclosed in the Issuer’s Prospectus Supplement filed with the Securities and Exchange Commission on October 30, 2018.

NAMES OF REPORTING PERSONS

Third Rock Ventures GP II, L.P.

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    Delaware

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

0

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

878,875

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.0% (1)

TYPE OF REPORTING PERSON

PN

NAMES OF REPORTING PERSONS

TRV GP II, LLC

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    Delaware

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

0

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

0

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

878,875

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.0% (1)

TYPE OF REPORTING PERSON

OO

NAMES OF REPORTING PERSONS

Mark Levin

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    United States

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

143,290

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

143,290

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

1,022,165

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.3% (1)

TYPE OF REPORTING PERSON

IN

NAMES OF REPORTING PERSONS

Kevin P. Starr

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    United States

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

33,398

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

33,398

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

912,273

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.1% (1)

TYPE OF REPORTING PERSON

IN

NAMES OF REPORTING PERSONS

Robert I. Tepper

CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

(a)  ☐        (b)  ☒

SEC USE ONLY

CITIZENSHIP OR PLACE OF ORGANIZATION

    United States

NUMBER OF  

SHARES   BENEFICIALLY   OWNED BY  

EACH  

REPORTING  

PERSON  

WITH  

SOLE VOTING POWER

84,378

SHARED VOTING POWER

878,875

SOLE DISPOSITIVE POWER

84,378

SHARED DISPOSITIVE POWER

878,875

AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

963,253

CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES  ☐

PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

2.2% (1)

TYPE OF REPORTING PERSON

IN

45 Sidney Street

Cambridge, MA 02139

(i) Third Rock Ventures II, L.P. (“TRV II”);

(ii)  Third Rock Ventures GP II, L.P. (“TRV GP II”), which is the sole general partner of TRV II;

(iii)  TRV GP II, LLC (“TRV GP II LLC”), which is the sole general partner of TRV GP II;

(iv) Mark Levin (“Levin”), a managing member of TRV GP II LLC;

(v)   Kevin P. Starr (“Starr”), a managing member of TRV GP II LLC; and

(vi ) Robert I. Tepper (“Tepper,” and collectively with TRV II, TRV GP II, TRV GP II LLC, Levin and Starr, the “Reporting Persons”), a managing member of TRV GP II LLC.

The address of the principal business office of each of the Reporting Persons is Third Rock Ventures, LLC, 29 Newbury Street, 3rd Floor, Boston, MA 02116.

Each of TRV II and TRV GP II is a Delaware limited partnership. TRV GP II LLC is a Delaware limited liability company. Levin, Tepper and Starr are United States citizens.

CUSIP Number:

09627Y109

Broker or dealer registered under Section 15 of the Act;

Bank as defined in Section 3(a)(6) of the Act;

Insurance company as defined in Section 3(a)(19) of the Act;

Investment company registered under Section 8 of the Investment Company Act of 1940;

An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

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;

A non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J);

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with Rule 240.13d-1(b)(1)(ii)(J), please specify the type of institution:

Reporting Person

TRV II

TRV GP II

TRV GP II LLC

Levin

Starr

Tepper

Sole power to vote or direct the vote

Shared power to vote or to direct the vote

Sole power to dispose or to direct the disposition of

Shared power to dispose or to direct the disposition of

Ownership of Five Percent or Less of a Class.

Ownership of More than Five Percent on Behalf of Another Person.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Identification and Classification of Members of the Group.

Notice of Dissolution of Group.

Certification.