<SEC-DOCUMENT>0001453687-24-000149.txt : 20241230
<SEC-HEADER>0001453687-24-000149.hdr.sgml : 20241230
<ACCEPTANCE-DATETIME>20241230161159
ACCESSION NUMBER:		0001453687-24-000149
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241226
FILED AS OF DATE:		20241230
DATE AS OF CHANGE:		20241230

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			English Emily
		CENTRAL INDEX KEY:			0002019791
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37798
		FILM NUMBER:		241589912

	MAIL ADDRESS:	
		STREET 1:		C/O CARTESIAN THERAPEUTICS, INC.
		STREET 2:		704 QUINCE ORCHARD ROAD
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Cartesian Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001453687
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		7495 NEW HORIZON WAY
		CITY:			FREDERICK
		STATE:			MD
		ZIP:			21703
		BUSINESS PHONE:		301-348-8698

	MAIL ADDRESS:	
		STREET 1:		7495 NEW HORIZON WAY
		CITY:			FREDERICK
		STATE:			MD
		ZIP:			21703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SELECTA BIOSCIENCES INC
		DATE OF NAME CHANGE:	20090109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1735593112.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-12-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001453687</issuerCik>
        <issuerName>Cartesian Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>RNAC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002019791</rptOwnerCik>
            <rptOwnerName>English Emily</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CARTESIAN THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>7495 NEW HORIZON WAY</rptOwnerStreet2>
            <rptOwnerCity>FREDERICK</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21703</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Head of Manufacturing</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common  Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-12-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7650</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.30</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25923</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.30</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-12-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7650</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-04-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common  Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7650</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>49369</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These options are currently exercisable for an additional 35,114 shares of Common Stock and become exercisable for a further 14,255 shares of Common Stock on March 22, 2025.</footnote>
        <footnote id="F2">On November 13, 2023, the issuer acquired the private Delaware corporation which was then known as Cartesian Therapeutics, Inc. (&quot;Old Cartesian&quot;) in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023. Options to purchase Old Cartesian common stock held by the reporting person were converted into options to purchase shares of Common Stock in connection with the merger.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew Bartholomae, Attorney-in-Fact for Emily English</signatureName>
        <signatureDate>2024-12-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
