<SEC-DOCUMENT>0001453687-21-000173.txt : 20211210
<SEC-HEADER>0001453687-21-000173.hdr.sgml : 20211210
<ACCEPTANCE-DATETIME>20211210170645
ACCESSION NUMBER:		0001453687-21-000173
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211208
FILED AS OF DATE:		20211210
DATE AS OF CHANGE:		20211210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brunn Carsten
		CENTRAL INDEX KEY:			0001760229

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37798
		FILM NUMBER:		211486139

	MAIL ADDRESS:	
		STREET 1:		C/O SELECTA BIOSCIENCES, INC.
		STREET 2:		480 ARSENAL WAY
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SELECTA BIOSCIENCES INC
		CENTRAL INDEX KEY:			0001453687
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		65 GROVE STREET
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472
		BUSINESS PHONE:		617-923-1400

	MAIL ADDRESS:	
		STREET 1:		65 GROVE STREET
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_163917398636442.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-12-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001453687</issuerCik>
        <issuerName>SELECTA BIOSCIENCES INC</issuerName>
        <issuerTradingSymbol>SELB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001760229</rptOwnerCik>
            <rptOwnerName>Brunn Carsten</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SELECTA BIOSCIENCES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>65 GROVE STREET</rptOwnerStreet2>
            <rptOwnerCity>WATERTOWN</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02472</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-12-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>37500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>322451</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On January 4, 2021, the reporting person was granted performance based restricted stock units for an aggregate of 75,000 shares of the Issuer's common stock (the &quot;Performance RSUs&quot;), which were earned based on the achievement of two separate performance conditions related to the Issuer's operating and research and development activities. The compensation committee of the board of directors of the Issuer has determined that the second of the performance conditions has been met, and accordingly 37,500 Performance RSUs vested on December 8, 2021,</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew Bartholomae, Attorney-in-Fact for Carsten Brunn</signatureName>
        <signatureDate>2021-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
