<SEC-DOCUMENT>0001125345-22-000075.txt : 20220617
<SEC-HEADER>0001125345-22-000075.hdr.sgml : 20220617
<ACCEPTANCE-DATETIME>20220617161836
ACCESSION NUMBER:		0001125345-22-000075
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20220615
FILED AS OF DATE:		20220617
DATE AS OF CHANGE:		20220617

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Karrels James
		CENTRAL INDEX KEY:			0001587477

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36112
		FILM NUMBER:		221024104

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

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:		9704 MEDICAL CENTER DRIVE
		CITY:			Rockville
		STATE:			MD
		ZIP:			20850
		BUSINESS PHONE:		301-251-5172

	MAIL ADDRESS:	
		STREET 1:		9704 MEDICAL CENTER DRIVE
		CITY:			ROCKVILLE
		STATE:			MD
		ZIP:			20850
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_165549709974837.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001587477</rptOwnerCik>
            <rptOwnerName>Karrels James</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9704 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>SVP, CFO and Secretary</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.47</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>191776</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This transaction was executed in multiple trades at prices ranging from $2.435 to $2.50. The reporting person undertakes to provide to MacroGenics, Inc., any security holder of MacroGenics, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.</footnote>
        <footnote id="F2">Owned jointly with reporting person's wife.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Lynn Cilinski, Attorney-in-Fact</signatureName>
        <signatureDate>2022-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
