<SEC-DOCUMENT>0001123292-16-001875.txt : 20160302
<SEC-HEADER>0001123292-16-001875.hdr.sgml : 20160302
<ACCEPTANCE-DATETIME>20160302175546
ACCESSION NUMBER:		0001123292-16-001875
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20160302
FILED AS OF DATE:		20160302
DATE AS OF CHANGE:		20160302

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Syndax Pharmaceuticals Inc
		CENTRAL INDEX KEY:			0001395937
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				320162505
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		460 TOTTEN POND ROAD
		STREET 2:		SUITE 650
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451
		BUSINESS PHONE:		781-419-1400

	MAIL ADDRESS:	
		STREET 1:		460 TOTTEN POND ROAD
		STREET 2:		SUITE 650
		CITY:			WALTHAM
		STATE:			MA
		ZIP:			02451

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			EVNIN LUKE
		CENTRAL INDEX KEY:			0001134657

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37708
		FILM NUMBER:		161478712

	MAIL ADDRESS:	
		STREET 1:		THE JOHN HANCOCK TOWER
		STREET 2:		200 CLARENDON STREET, 54TH STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2016-03-02</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001395937</issuerCik>
        <issuerName>Syndax Pharmaceuticals Inc</issuerName>
        <issuerTradingSymbol>SNDX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001134657</rptOwnerCik>
            <rptOwnerName>EVNIN LUKE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SYNDAX PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>400 TOTTEN POND ROAD, SUITE 110</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02451</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A-1 Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1138210</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series B-1 Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>718396</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Series C-1 Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>312085</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.35</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-12-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10167</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.20</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-08-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16800</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reported securities are convertible at any time on a one-for-one basis, in whole or in part, at the option of the holder, have no expiration date, and will convert into shares of common stock immediately prior to the closing of the Issuer's initial public offering.</footnote>
        <footnote id="F2">The securities are owned directly by MPM BioVentures IV-QP, L.P. (&quot;MPM IV-QP&quot;), MPM BioVentures IV Strategic Fund, L.P. (&quot;MPM Strategic Fund&quot;), MPM BioVentures IV GMBH &amp; Co. Beteiligungs KG (&quot;MPM Beteiligungs&quot;) and MPM Asset Management Investors BV4 LLC (&quot;MPM BV4&quot; and collectively, the &quot;MPM Entities&quot;). Dr. Evnin is a member of MPM BioVentures IV LLC, (&quot;MPM IV LLC&quot;), which is the managing member of MPM BioVentures IV GP LLC, which is (i) the general partner of each of MPM IV-QP and MPM Strategic Fund, and (ii) the managing limited partner of MPM Beteiligungs. MPM IV LLC is the manager of MPM BV4. As a result, Dr. Evnin shares the power to vote, acquire, hold and dispose of the shares owned by the MPM Entities. Dr. Evnin disclaims beneficial ownership of all shares held by the MPM Entities, except to the extent of his actual pecuniary interest therein.</footnote>
        <footnote id="F3">Twenty-five percent (25%) of the total number of shares underlying the option vested on December 18, 2014, and one forty-eighth (1/48th) of the total number of shares underlying the option vest monthly thereafter on the last day of each month, subject to the reporting person's continuous service on the relevant vesting dates.</footnote>
        <footnote id="F4">Twenty-five percent (25%) of the total number of shares underlying the option vested on August 18, 2015, and one forty-eighth (1/48th) of the total number of shares underlying the option vest monthly thereafter on the last day of each month, subject to the reporting person's continuous service on the relevant vesting dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael A. Metzger, Attorney-in-Fact</signatureName>
        <signatureDate>2016-03-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>evninpoa.htm
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
<html>
<head>
<title></title>
<!--Licensed to: Hogan Lovells US LLP
    Document created using EDGARfilings PROfile 3.6.1.0
    Copyright 1995 - 2016 Summit Financial Printing, LLC.  All rights reserved.-->
</head>
<body style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif" bgcolor="#ffffff" text="#000000">
<div>
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: bold; TEXT-ALIGN: center">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: bold; TEXT-ALIGN: center">Power of Attorney</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: normal; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">The undersigned, a member of the Board of Directors of Syndax Pharmaceuticals, Inc., a Delaware corporation (the "<font style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif"><u>Company</u></font>"), hereby constitutes and appoints Briggs W. Morrison, Michael A. Metzger and John S. Pallies, for so long as each such person is an employee of the Company, and Laura A. Berezin, for so long as she is a partner of a law firm representing the Company, the undersigned's true and lawful attorney-in-fact, each with the power to act alone for the undersigned and in the undersigned's name, place and stead, to:</div>

<div>
<table id="9e8223a1258048e09d83ff36fce5a98e" class="DSPFListTable" style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; WIDTH: 100%; MARGIN-TOP: 12pt" cellspacing="0" cellpadding="0">
<tr>
<td style="WIDTH: 72pt; VERTICAL-ALIGN: top; align: right">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-LEFT: 36pt; MARGIN-TOP: 12pt">1.</div>
</td>
<td style="WIDTH: auto; VERTICAL-ALIGN: top">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt">Prepare, complete and execute Forms 3, 4 and 5 under the Securities Exchange Act of 1934, as amended (the "<font style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif"><u>Exchange Act</u></font>"), and other forms and all amendments thereto on the undersigned's behalf as such attorney-in-fact shall in his or her discretion determine to be required or advisable pursuant to Section 16 of the Exchange Act and the rules and regulations promulgated thereunder, or any successor laws and regulations, as a consequence of the undersigned's beneficial ownership of securities of the Company or changes in such beneficial ownership; and</div>
</td>
</tr>
</table>
</div>

<div>
<table id="37d4f015b0d24cd8a0ff9f14b5e2bd37" class="DSPFListTable" style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; WIDTH: 100%; MARGIN-TOP: 12pt" cellspacing="0" cellpadding="0">
<tr>
<td style="WIDTH: 72pt; VERTICAL-ALIGN: top; align: right">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-LEFT: 36pt; MARGIN-TOP: 12pt">2.</div>
</td>
<td style="WIDTH: auto; VERTICAL-ALIGN: top">
<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt">Do all acts necessary in order to file such forms and amendments with the Securities and Exchange Commission, any securities exchange or national association, the Company and such other persons or agencies as the attorney-in-fact shall deem appropriate.</div>
</td>
</tr>
</table>
</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: normal; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">The undersigned hereby ratifies and confirms all that said attorneys-in-fact and agents shall do or cause to be done by virtue hereof. The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned, are not assuming, nor is the Company assuming, any of the undersigned's responsibilities to comply with or liability under Section 16 of the Exchange Act or any rules and regulations promulgated thereunder or any successor laws and regulations.</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: normal; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">This Power of Attorney shall remain in full force and effect until the undersigned is no longer required to file Forms 3, 4, or 5 with respect to the undersigned's beneficial ownership of securities of the Company or changes in such beneficial ownership, unless earlier revoked by the undersigned in a signed writing delivered to the Company and the foregoing attorneys-in-fact.</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; FONT-WEIGHT: normal; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">The undersigned has executed this Power of Attorney as of January 21, 2016.</div>
</div>
</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">
<table id="a0be588bd5b341d5b4e1fc669d4dd409" style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; WIDTH: 100%" cellspacing="0" cellpadding="0" border="0">
<tr>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%; BORDER-BOTTOM: #000000 1px solid">
<div style="TEXT-ALIGN: left">/s/ Luke Evnin</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
</tr>

<tr>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%; FONT-WEIGHT: bold">
<div style="TEXT-ALIGN: left">Luke Evnin</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
</tr>

<tr>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
<td style="WIDTH: 20%">
<div>&#160;</div>
</td>
</tr>
</table>
</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">&#160;</div>

<div style="FONT-SIZE: 12pt; FONT-FAMILY: 'Times New Roman', Times, serif; TEXT-ALIGN: left; MARGIN-TOP: 12pt; TEXT-INDENT: 36pt">&#160;</div>
</div>
</body>
</html>

</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
