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 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:14pt; font-family:Times New Roman" ALIGN="center"><B>UNITED STATES </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:14pt; font-family:Times New Roman" ALIGN="center"><B>SECURITIES AND EXCHANGE COMMISSION </B></P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>WASHINGTON, D.C. 20549 </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P><center>
<P STYLE="line-height:6.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:18pt; font-family:Times New Roman" ALIGN="center"><B>FORM <FONT
STYLE="white-space:nowrap">8-K</FONT> </B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">CURRENT REPORT </P>
<P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Pursuant to Section&nbsp;13 or 15(d) of the Securities Exchange Act of 1934 </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">Date of Report (Date of earliest event reported): February&nbsp;11, 2019 </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:22pt; font-family:Times New Roman" ALIGN="center"><B>Merrimack Pharmaceuticals, Inc. </B></P>
<P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center">(Exact Name of Registrant as
Specified in its Charter) </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Delaware</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">001-35409</FONT></B></P></TD>

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<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B><FONT STYLE="white-space:nowrap">04-3210530</FONT></B></P></TD></TR>
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<TD VALIGN="bottom" ALIGN="center"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(State or Other Jurisdiction</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>of Incorporation)</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center"><B>(Commission<BR>File Number)</B></TD>
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<TD VALIGN="bottom" ALIGN="center"><B>(IRS Employer<BR>Identification No.)</B></TD></TR></TABLE> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD WIDTH="48%"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" NOWRAP ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>One Kendall Square, Suite B7201</B></P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Cambridge, MA</B></P></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>02139</B></P></TD></TR>
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<TD VALIGN="bottom" ALIGN="center"><B>(Address of Principal Executive Offices)</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="center"><B>(Zip Code)</B></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>Registrant&#146;s telephone number, including area code: (617) <FONT
STYLE="white-space:nowrap">441-1000</FONT> </B></P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<P STYLE="line-height:1.0pt;margin-top:0pt;margin-bottom:2pt;border-bottom:1.00pt solid #000000">&nbsp;</P> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:8pt; font-family:Times New Roman" ALIGN="center"><B>(Former Name or Former Address, if
Changed Since Last Report) </B></P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Check the appropriate box below if the Form <FONT STYLE="white-space:nowrap">8-K</FONT> filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the following provisions (<I>see</I> General Instruction A.2. below): </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">&#9744; Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">&#9744; Soliciting material pursuant to Rule <FONT STYLE="white-space:nowrap">14a-12</FONT> under the Exchange Act (17 CFR <FONT
STYLE="white-space:nowrap">240.14a-12)</FONT> </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">&#9744; <FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to
Rule <FONT STYLE="white-space:nowrap">14d-2(b)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.14d-2(b))</FONT> </P>
<P STYLE="margin-top:12pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">&#9744; <FONT STYLE="white-space:nowrap">Pre-commencement</FONT> communications pursuant to Rule
<FONT STYLE="white-space:nowrap">13e-4(c)</FONT> under the Exchange Act (17 CFR <FONT STYLE="white-space:nowrap">240.13e-4(c))</FONT> </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Indicate by check
mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR 230.405) or Rule <FONT STYLE="white-space:nowrap">12b-2</FONT> of the Securities Exchange Act of 1934 (17 CFR <FONT
STYLE="white-space:nowrap">240.12b-2).</FONT> </P> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Emerging growth company &#9744; </P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or
revised financial accounting standards provided pursuant to Section&nbsp;13(a) of the Exchange Act.&nbsp;&nbsp;&nbsp;&nbsp;&#9744; </P>
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<TD WIDTH="9%" VALIGN="top" ALIGN="left"><B>Item&nbsp;5.02.</B></TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left"><B>Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers;
Compensatory Arrangements of Certain Officers. </B></P></TD></TR></TABLE> <P STYLE="margin-top:6pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">On February&nbsp;11, 2019, the Board of Directors (the &#147;Board&#148;) of
Merrimack Pharmaceuticals, Inc. (the &#147;Company&#148;) approved a bonus award pursuant to the Company&#146;s 2018 annual performance-based cash bonus program (the &#147;2018 Bonus Program&#148;) for Richard Peters, the Company&#146;s President
and Chief Executive Officer, as set forth below: </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TD VALIGN="bottom" NOWRAP> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; border-bottom:1.00pt solid #000000; display:table-cell; font-size:10pt; font-family:Times New Roman; "><B>2018 Base Salary</B></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Target&nbsp;Bonus<BR>Percentage</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Target&nbsp;Cash<BR>Bonus</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>2018&nbsp;Actual<BR>Cash Bonus</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Actual&nbsp;Bonus<BR>as % of<BR>Salary</B></TD>
<TD VALIGN="bottom">&nbsp;</TD></TR>


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<TD VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">$722,084</P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="right">65</TD>
<TD NOWRAP VALIGN="bottom">%&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">469,355</TD>
<TD NOWRAP VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">610,161</TD>
<TD NOWRAP VALIGN="bottom">(1)&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" ALIGN="right">84.5</TD>
<TD NOWRAP VALIGN="bottom">%&nbsp;</TD></TR>
</TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(1)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The target cash bonus for 2018 for Dr.&nbsp;Peters is based on the achievement of the Company&#146;s corporate
objectives. The Board determined that the Company achieved its corporate objectives for 2018 at a level of 110%. In addition, the Board used its discretion to further increase Dr.&nbsp;Peters&#146; bonus award to 130% of his target cash bonus to
recognize his leadership and engagement. </P></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Board also increased Dr.&nbsp;Peters&#146; base salary to $743,746, retroactive to
January&nbsp;1, 2019. </P> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Also on February&nbsp;11, 2019, the Organization and Compensation Committee (the &#147;Committee&#148;) of the Board approved a
bonus award pursuant to the 2018 Bonus Program for each of the Company&#146;s other named executive officers, as set forth below: </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">


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<TD VALIGN="bottom" NOWRAP> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; border-bottom:1.00pt solid #000000; display:table-cell; font-size:10pt; font-family:Times New Roman; "><B>Name</B></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>2018&nbsp;Base<BR>Salary</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Target&nbsp;Bonus<BR>Percentage</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Target&nbsp;Cash<BR>Bonus</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>2018&nbsp;Actual<BR>Cash<BR>Bonus(1)</B></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>Actual&nbsp;Bonus<BR>as % of<BR>Salary</B></TD>
<TD VALIGN="bottom">&nbsp;</TD></TR>


<TR BGCOLOR="#cceeff" STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Daryl C. Drummond</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman"><I>Head of Research</I></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">276,717</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">35</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">96,851</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">107,505</TD>
<TD NOWRAP VALIGN="top">(2)&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">38.9</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Jean M. Franchi</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman"><I>Chief Financial Officer</I></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">402,915</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">35</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">141,020</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">162,173</TD>
<TD NOWRAP VALIGN="top">(3)&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">40.2</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD></TR>
<TR BGCOLOR="#cceeff" STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Jeffrey A. Munsie</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman"><I>General Counsel and Head of Corporate Operations</I></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">367,200</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">35</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">128,520</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">140,087</TD>
<TD NOWRAP VALIGN="top">(4)&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">38.2</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Sergio L. Santillana</P>
<P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman"><I>Chief Medical Officer</I></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">379,171</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">35</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">132,710</TD>
<TD NOWRAP VALIGN="top">&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="top">$</TD>
<TD VALIGN="top" ALIGN="right">143,327</TD>
<TD NOWRAP VALIGN="top">(5)&nbsp;</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">&nbsp;</TD>
<TD VALIGN="top" ALIGN="right">37.8</TD>
<TD NOWRAP VALIGN="top">%&nbsp;</TD></TR>
</TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TR style = "page-break-inside:avoid">
<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(1)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The target cash bonus for 2018 for Dr.&nbsp;Drummond, Ms.&nbsp;Franchi, Mr.&nbsp;Munsie and Dr.&nbsp;Santillana
is based 80% on the achievement of the Company&#146;s corporate objectives and 20% on the achievement of specified individual objectives. The Board determined that the Company achieved its corporate objectives for 2018 at a level of 110%.
</P></TD></TR></TABLE>
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<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(2)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Committee determined that Dr.&nbsp;Drummond achieved his individual objectives for 2018 at a level of 115%,
which made him eligible for a bonus award equal to 111% of his target cash bonus. </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(3)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Committee determined that Ms.&nbsp;Franchi achieved her individual objectives for 2018 at a level of 135%,
which made her eligible for a bonus award equal to 115% of her target cash bonus. </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(4)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Committee determined that Mr.&nbsp;Munsie achieved his individual objectives for 2018 at a level of 105%,
which made him eligible for a bonus award equal to 109% of his target cash bonus. </P></TD></TR></TABLE> <P STYLE="font-size:6pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR style = "page-break-inside:avoid">
<TD WIDTH="4%">&nbsp;</TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left">(5)</TD>
<TD ALIGN="left" VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman; " ALIGN="left">The Committee determined that Dr.&nbsp;Santillana achieved his individual objectives for 2018 at a level of
100%, which made him eligible for a bonus award equal to 108% of his target cash bonus. </P></TD></TR></TABLE> <P STYLE="margin-top:12pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">The Committee also increased the base salary
for each of the Company&#146;s other named executive officers, retroactive to January&nbsp;1, 2019, as set forth below: </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="84%" BORDER="0" STYLE="BORDER-COLLAPSE:COLLAPSE; font-family:Times New Roman; font-size:10pt" ALIGN="center">


<TR>
<TD WIDTH="81%"></TD>
<TD VALIGN="bottom" WIDTH="13%"></TD>
<TD></TD>
<TD></TD>
<TD></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="bottom" NOWRAP> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; border-bottom:1.00pt solid #000000; display:table-cell; font-size:10pt; font-family:Times New Roman; "><B>Name</B></P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom" COLSPAN="2" ALIGN="center" STYLE="border-bottom:1.00pt solid #000000"><B>2019&nbsp;Base&nbsp;Salary</B></TD>
<TD VALIGN="bottom">&nbsp;</TD></TR>


<TR BGCOLOR="#cceeff" STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Daryl C. Drummond</P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">285,019</TD>
<TD NOWRAP VALIGN="bottom">&nbsp;</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Jean M. Franchi</P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">415,003</TD>
<TD NOWRAP VALIGN="bottom">&nbsp;</TD></TR>
<TR BGCOLOR="#cceeff" STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Jeffrey A. Munsie</P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">378,216</TD>
<TD NOWRAP VALIGN="bottom">&nbsp;</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"> <P STYLE=" margin-top:0pt ; margin-bottom:0pt; margin-left:1.00em; text-indent:-1.00em; font-size:10pt; font-family:Times New Roman">Sergio L. Santillana</P></TD>
<TD VALIGN="bottom">&nbsp;&nbsp;</TD>
<TD VALIGN="bottom">$</TD>
<TD VALIGN="bottom" ALIGN="right">390,546</TD>
<TD NOWRAP VALIGN="bottom">&nbsp;</TD></TR>
</TABLE>
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<Center><DIV STYLE="width:8.5in" align="left">
 <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman" ALIGN="center"><B>SIGNATURE </B></P>
<P STYLE="margin-top:6pt; margin-bottom:0pt; text-indent:4%; font-size:10pt; font-family:Times New Roman">Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by
the undersigned hereunto duly authorized. </P> <P STYLE="font-size:12pt;margin-top:0pt;margin-bottom:0pt">&nbsp;</P>
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<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top" COLSPAN="3"><B>MERRIMACK PHARMACEUTICALS, INC.</B></TD></TR>
<TR STYLE="font-size:1pt">
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top">Date: February&nbsp;15, 2019</TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top">By:</TD>
<TD VALIGN="bottom" STYLE=" BORDER-BOTTOM:1px solid #000000">&nbsp;</TD>
<TD VALIGN="top" STYLE="BORDER-BOTTOM:1px solid #000000">/s/ Jeffrey A. Munsie</TD></TR>
<TR STYLE="page-break-inside:avoid ; font-family:Times New Roman; font-size:10pt">
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom">&nbsp;</TD>
<TD VALIGN="top"> <P STYLE="margin-top:0pt; margin-bottom:0pt; font-size:10pt; font-family:Times New Roman">Jeffrey A. Munsie</P> <P STYLE="margin-top:0pt; margin-bottom:1pt; font-size:10pt; font-family:Times New Roman">General Counsel</P></TD></TR>
</TABLE>
</DIV></Center>

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{"company-data": {"conformed-name": "MERRIMACK PHARMACEUTICALS INC", "cik": "0001274792", "assigned-sic": "2834", "irs-number": "000000000", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-35409", "film-number": "19611594"}, "business-address": {"street1": "ONE KENDALL SQUARE", "street2": "SUITE B7201", "city": "CAMBRIDGE", "state": "MA", "zip": "02139", "phone": "617-441-1000"}, "mail-address": {"street1": "ONE KENDALL SQUARE", "street2": "SUITE B7201", "city": "CAMBRIDGE", "state": "MA", "zip": "02139"}}
8-K
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
FORM
8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): February 11, 2019
Merrimack Pharmaceuticals, Inc.
(Exact Name of Registrant as
Specified in its Charter)
Delaware
001-35409
04-3210530
(State or Other Jurisdiction
of Incorporation)
(Commission
File Number)
(IRS Employer
Identification No.)
One Kendall Square, Suite B7201
Cambridge, MA
02139
(Address of Principal Executive Offices)
(Zip Code)
Registrant's telephone number, including area code: (617)
441-1000
(Former Name or Former Address, if
Changed Since Last Report)
Check the appropriate box below if the Form
8-K
filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the following provisions (
see
General Instruction A.2. below):
☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐ Soliciting material pursuant to Rule
14a-12
under the Exchange Act (17 CFR
240.14a-12)
☐
Pre-commencement
communications pursuant to
Rule
14d-2(b)
under the Exchange Act (17 CFR
240.14d-2(b))
☐
Pre-commencement
communications pursuant to Rule
13e-4(c)
under the Exchange Act (17 CFR
240.13e-4(c))
Indicate by check
mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR 230.405) or Rule
12b-2
of the Securities Exchange Act of 1934 (17 CFR
240.12b-2).
Emerging growth company ☐
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or
revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.    ☐
Item 5.02.
Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers;
Compensatory Arrangements of Certain Officers.
On February 11, 2019, the Board of Directors (the "Board") of
Merrimack Pharmaceuticals, Inc. (the "Company") approved a bonus award pursuant to the Company's 2018 annual performance-based cash bonus program (the "2018 Bonus Program") for Richard Peters, the Company's President
and Chief Executive Officer, as set forth below:
2018 Base Salary
Target Bonus
Percentage
Target Cash
Bonus
2018 Actual
Cash Bonus
Actual Bonus
as % of
Salary
$722,084
65
%
$
469,355
$
610,161
(1)
84.5
%
(1)
The target cash bonus for 2018 for Dr. Peters is based on the achievement of the Company's corporate
objectives. The Board determined that the Company achieved its corporate objectives for 2018 at a level of 110%. In addition, the Board used its discretion to further increase Dr. Peters' bonus award to 130% of his target cash bonus to
recognize his leadership and engagement.
The Board also increased Dr. Peters' base salary to $743,746, retroactive to
January 1, 2019.
Also on February 11, 2019, the Organization and Compensation Committee (the "Committee") of the Board approved a
bonus award pursuant to the 2018 Bonus Program for each of the Company's other named executive officers, as set forth below:
Name
2018 Base
Salary
Target Bonus
Percentage
Target Cash
Bonus
2018 Actual
Cash
Bonus(1)
Actual Bonus
as % of
Salary
Daryl C. Drummond
Head of Research
$
276,717
35
%
$
96,851
$
107,505
(2)
38.9
%
Jean M. Franchi
Chief Financial Officer
$
402,915
35
%
$
141,020
$
162,173
(3)
40.2
%
Jeffrey A. Munsie
General Counsel and Head of Corporate Operations
$
367,200
35
%
$
128,520
$
140,087
(4)
38.2
%
Sergio L. Santillana
Chief Medical Officer
$
379,171
35
%
$
132,710
$
143,327
(5)
37.8
%
(1)
The target cash bonus for 2018 for Dr. Drummond, Ms. Franchi, Mr. Munsie and Dr. Santillana
is based 80% on the achievement of the Company's corporate objectives and 20% on the achievement of specified individual objectives. The Board determined that the Company achieved its corporate objectives for 2018 at a level of 110%.
(2)
The Committee determined that Dr. Drummond achieved his individual objectives for 2018 at a level of 115%,
which made him eligible for a bonus award equal to 111% of his target cash bonus.
(3)
The Committee determined that Ms. Franchi achieved her individual objectives for 2018 at a level of 135%,
which made her eligible for a bonus award equal to 115% of her target cash bonus.
(4)
The Committee determined that Mr. Munsie achieved his individual objectives for 2018 at a level of 105%,
which made him eligible for a bonus award equal to 109% of his target cash bonus.
(5)
The Committee determined that Dr. Santillana achieved his individual objectives for 2018 at a level of
100%, which made him eligible for a bonus award equal to 108% of his target cash bonus.
The Committee also increased the base salary
for each of the Company's other named executive officers, retroactive to January 1, 2019, as set forth below:
Name
2019 Base Salary
Daryl C. Drummond
$
285,019
Jean M. Franchi
$
415,003
Jeffrey A. Munsie
$
378,216
Sergio L. Santillana
$
390,546
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by
the undersigned hereunto duly authorized.
MERRIMACK PHARMACEUTICALS, INC.
Date: February 15, 2019
By:
/s/ Jeffrey A. Munsie
Jeffrey A. Munsie
General Counsel