<SEC-DOCUMENT>0001140361-14-039565.txt : 20141030
<SEC-HEADER>0001140361-14-039565.hdr.sgml : 20141030
<ACCEPTANCE-DATETIME>20141030165118
ACCESSION NUMBER:		0001140361-14-039565
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20141028
FILED AS OF DATE:		20141030
DATE AS OF CHANGE:		20141030

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MACROGENICS INC
		CENTRAL INDEX KEY:			0001125345
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		9640 MEDICAL CENTER DRIVE
		CITY:			Rockville
		STATE:			MD
		ZIP:			20850
		BUSINESS PHONE:		301-251-5172

	MAIL ADDRESS:	
		STREET 1:		9640 MEDICAL CENTER DRIVE
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SARAN ATUL
		CENTRAL INDEX KEY:			0001591070

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36112
		FILM NUMBER:		141183796

	MAIL ADDRESS:	
		STREET 1:		C/O ZENCOR, INC.
		STREET 2:		111 WEST LEMON AVENUE
		CITY:			MONROVIA
		STATE:			CA
		ZIP:			91016
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-10-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001125345</issuerCik>
        <issuerName>MACROGENICS INC</issuerName>
        <issuerTradingSymbol>MGNX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001591070</rptOwnerCik>
            <rptOwnerName>SARAN ATUL</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9640 MEDICAL CENTER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROCKVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20850</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See remarks</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2014-10-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>865</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>21.79</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21635</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Consists of restricted stock units granted under the MacroGenics 2013 Equity Incentive Plan.</footnote>
        <footnote id="F2">Payment of tax liability as required upon vesting of restricted stock units under terms of restricted stock arrangement</footnote>
    </footnotes>

    <remarks>Senior Vice President, General Counsel and Compliance Officer</remarks>

    <ownerSignature>
        <signatureName>/s/Lynn Cilinski, attorney-in-fact</signatureName>
        <signatureDate>2014-10-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
