SCHEDULE 13G
Amendment No. 2
MERRIMACK PHARMACEUTICALS INC
Common Stock
Cusip #590328100
Cusip #590328100
Item 1: Reporting Person - FMR LLC
Item 4: Delaware
Item 5: 86,700
Item 6: 0
Item 7: 15,352,128
Item 8: 0
Item 9: 15,352,128
Item 11: 15.000%
Item 12: HC
Cusip #590328100
Item 1: Reporting Person - Edward C. Johnson 3d
Item 4: United States of America
Item 5: 0
Item 6: 0
Item 7: 15,352,128
Item 8: 0
Item 9: 15,352,128
Item 11: 15.000%
Item 12: IN
SCHEDULE 13G - TO BE INCLUDED IN
STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
Item 1(a). Name of Issuer:
MERRIMACK PHARMACEUTICALS
INC
Item 1(b). Name of Issuer's Principal Executive Offices:
One Kendall Square
Ste 87201
Cambridge, MA 02139
USA
Item 2(a). Name of Person Filing:
FMR LLC
Item 2(b). Address or Principal Business Office or, if None,
Residence:
245 Summer Street, Boston,
Massachusetts 02210
Item 2(c). Citizenship:
Not applicable
Item 2(d). Title of Class of Securities:
Common Stock
Item 2(e). CUSIP Number:
590328100
Item 3. This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b)
and the person filing, FMR LLC, is a parent holding company
in accordance with Section 240.13d-1(b)(ii)(G). (Note: See
Item 7).
Item 4. Ownership
(a) Amount Beneficially Owned: 15,352,128
(b) Percent of Class: 15.000%
(c) Number of shares as to which such
person has:
(i) sole power to vote or to direct
the vote: 86,700
(ii) shared power to vote or to
direct the vote: 0
(iii) sole power to dispose or to
direct the disposition of: 15,352,128
(iv) shared power to dispose or to
direct the disposition of: 0
Item 5. Ownership of Five Percent or Less of a Class.
Not applicable.
Item 6. Ownership of More than Five Percent on Behalf of Another
Person.
Various persons have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the
sale of, the Common Stock of MERRIMACK
PHARMACEUTICALS INC. The interest of one person,
Fidelity Growth Company Fund, an investment company
registered under the Investment Company Act of 1940, in the
Common Stock of MERRIMACK PHARMACEUTICALS
INC, amounted to 9,565,121 shares or 9.346% of the total
outstanding Common Stock at December 31, 2013.
Item 7. Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on By the Parent
Holding Company.
See attached Exhibit A.
Item 8. Identification and Classification of Members of
the Group.
Not applicable. See attached Exhibit A.
Item 9. Notice of Dissolution of Group.
Not applicable.
Item 10. Certification.
By signing below I certify that, to the best of my knowledge
and belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the
purpose of and do not have the effect of changing or
influencing the control of the issuer of such securities and
were not acquired in connection with or as a participant in any
transaction having such purpose or effect.
Signature
After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement
is true, complete and correct.
February 13, 2014
Date
/s/ Scott C. Goebel
Signature
Scott C. Goebel
Duly authorized under Power of Attorney
effective as of June 1, 2008 by and on behalf of FMR LLC
and its direct and indirect subsidiaries
SCHEDULE 13G - TO BE INCLUDED IN
STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
Pursuant to the instructions in Item 7 of Schedule 13G,
Fidelity Management & Research Company ("Fidelity"), 245
Summer Street, Boston, Massachusetts 02210, a wholly-
owned subsidiary of FMR LLC and an investment adviser
registered under Section 203 of the Investment Advisers Act
of 1940, is the beneficial owner of 14,988,379 shares or
14.645% of the Common Stock outstanding of MERRIMACK
PHARMACEUTICALS INC ("the Company") as a result of
acting as investment adviser to various investment companies
registered under Section 8 of the Investment Company Act of
1940.
Edward C. Johnson 3d and FMR LLC, through its
control of Fidelity, and the funds each has sole power to
dispose of the 14,988,379 shares owned by the Funds.
Fidelity SelectCo, LLC ("SelectCo"), 1225 17th Street,
Suite 1100, Denver, Colorado 80202, a wholly-owned
subsidiary of FMR LLC and an investment adviser registered
under Section 203 of the Investment Advisers Act of 1940, is
the beneficial owner of 277,049 shares or 0.271% of the
Common Stock outstanding of MERRIMACK
PHARMACEUTICALS INC ("the Company") as a result of
acting as investment adviser to various investment companies
registered under Section 8 of the Investment Company Act of
1940 (the "SelectCo Funds").
Edward C. Johnson 3d and FMR LLC, through its
control of SelectCo, and the SelectCo Funds each has sole
power to dispose of the 277,049 owned by the SelectCo
Funds.
The ownership of one investment company, Fidelity
Growth Company Fund, amounted to 9,565,121 shares or
9.346% of the Common Stock outstanding. Fidelity Growth
Company Fund has its principal business office at 245
Summer Street, Boston, Massachusetts 02210.
Members of the family of Edward C. Johnson 3d,
Chairman of FMR LLC, are the predominant owners, directly
or through trusts, of Series B voting common shares of FMR
LLC, representing 49% of the voting power of FMR LLC.
The Johnson family group and all other Series B shareholders
have entered into a shareholders' voting agreement under
which all Series B voting common shares will be voted in
accordance with the majority vote of Series B voting common
shares. Accordingly, through their ownership of voting
common shares and the execution of the shareholders' voting
agreement, members of the Johnson family may be deemed,
under the Investment Company Act of 1940, to form a
controlling group with respect to FMR LLC.
Neither FMR LLC nor Edward C. Johnson 3d,
Chairman of FMR LLC, has the sole power to vote or direct
the voting of the shares owned directly by the Fidelity Funds,
which power resides with the Funds' Boards of Trustees.
Fidelity carries out the voting of the shares under written
guidelines established by the Funds' Boards of Trustees.
Pyramis Global Advisors Trust Company ("PGATC"),
900 Salem Street, Smithfield, Rhode Island, 02917, an indirect
wholly-owned subsidiary of FMR LLC and a bank as defined
in Section 3(a)(6) of the Securities Exchange Act of 1934, is
the beneficial owner of 86,700 shares or 0.085% of the
outstanding Common Stock of the MERRIMACK
PHARMACEUTICALS INC as a result of its serving as
investment manager of institutional accounts owning such
shares.
Edward C. Johnson 3d and FMR LLC, through its
control of Pyramis Global Advisors Trust Company, each has
sole dispositive power over 86,700 shares and sole power to
vote or to direct the voting of 86,700 shares of Common Stock
owned by the institutional accounts managed by PGATC as
reported above.
SCHEDULE 13G - TO BE INCLUDED IN
STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
RULE 13d-1(f)(1) AGREEMENT
The undersigned persons, on February 13, 2014, agree
and consent to the joint filing on their behalf of this Schedule
13G in connection with their beneficial ownership of the
Common Stock of MERRIMACK PHARMACEUTICALS
INC at December 31, 2013.
FMR LLC
By /s/ Scott C. Goebel
Scott C. Goebel
Duly authorized under Power of Attorney effective as
of June 1, 2008, by and on behalf of FMR LLC and its direct
and indirect subsidiaries
Edward C. Johnson 3d
By /s/ Scott C. Goebel
Scott C. Goebel
Duly authorized under Power of Attorney effective as
of June 1, 2008, by and on behalf of Edward C. Johnson 3d
Fidelity Management & Research Company
By /s/ Scott C. Goebel
Scott C. Goebel
Senior V.P. and General Counsel
Fidelity Growth Company Fund
By /s/ Scott C. Goebel
Scott C. Goebel
Secretary