<SEC-DOCUMENT>0001104659-16-130150.txt : 20160629
<SEC-HEADER>0001104659-16-130150.hdr.sgml : 20160629
<ACCEPTANCE-DATETIME>20160629164804
ACCESSION NUMBER:		0001104659-16-130150
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160627
FILED AS OF DATE:		20160629
DATE AS OF CHANGE:		20160629

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:		480 ARSENAL STREET
		STREET 2:		BUILDING ONE
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472
		BUSINESS PHONE:		617-923-1400

	MAIL ADDRESS:	
		STREET 1:		480 ARSENAL STREET
		STREET 2:		BUILDING ONE
		CITY:			WATERTOWN
		STATE:			MA
		ZIP:			02472

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Farokhzad Omid
		CENTRAL INDEX KEY:			0001586852

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37798
		FILM NUMBER:		161739371

	MAIL ADDRESS:	
		STREET 1:		C/O BIND THERAPEUTICS, INC.
		STREET 2:		325 VASSAR ST
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-06-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001586852</rptOwnerCik>
            <rptOwnerName>Farokhzad Omid</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SELECTA BIOSCIENCES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>480 ARSENAL STREET, BUILDING ONE</rptOwnerStreet2>
            <rptOwnerCity>WATERTOWN</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02472</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-06-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>22081</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25626</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series E Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-06-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>14244</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>22081</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reportable securities are held by BioDynamics Core, L.P., which is managed by BioDynamics, LLC, of which the Reporting Person is a member. The Reporting Person disclaims beneficial ownership of these securities, except to the extent of any pecuniary interest therein, and the filing of this report is not an admission that the Reporting Person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F2">The preferred stock is convertible at any time, at the holder's election and has no expiration date. The preferred stock automatically converted into common stock on an approximately 1-for-1.550115 basis upon the closing of the Issuer's initial public offering.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ David Siewers, attorney-in-fact</signatureName>
        <signatureDate>2016-06-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
