<SEC-DOCUMENT>0001453687-24-000117.txt : 20241015
<SEC-HEADER>0001453687-24-000117.hdr.sgml : 20241015
<ACCEPTANCE-DATETIME>20241015165332
ACCESSION NUMBER:		0001453687-24-000117
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241011
FILED AS OF DATE:		20241015
DATE AS OF CHANGE:		20241015

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kalayoglu Murat
		CENTRAL INDEX KEY:			0002000002
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37798
		FILM NUMBER:		241372430

	MAIL ADDRESS:	
		STREET 1:		C/O CARTESIAN THERAPEUTICS, INC.
		STREET 2:		704 QUINCE ORCHARD RD
		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:		704 QUINCE ORCHARD RD
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878
		BUSINESS PHONE:		617-923-1400

	MAIL ADDRESS:	
		STREET 1:		704 QUINCE ORCHARD RD
		CITY:			GAITHERSBURG
		STATE:			MD
		ZIP:			20878

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SELECTA BIOSCIENCES INC
		DATE OF NAME CHANGE:	20090109
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1729025606.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-10-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002000002</rptOwnerCik>
            <rptOwnerName>Kalayoglu Murat</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CARTESIAN THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>704 QUINCE ORCHARD ROAD</rptOwnerStreet2>
            <rptOwnerCity>GAITHERSBURG</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20878</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common  Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-10-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1518373</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4555260</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by trust</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common  Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>506377</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Non-Voting Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-10-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>45551.19</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common  Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1518373</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>56402.254</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by trust</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On October 11, 2024, a trust (the &quot;Trust&quot;) for the benefit of the reporting person's spouse and children elected to convert a portion of its shares of the issuer's Series A Non-Voting Convertible Preferred Stock into shares of the issuer's common stock. The remaining shares of the issuer's Series A Non-Voting Convertible Preferred Stock held by the Trust are subject to a beneficial ownership limitation.</footnote>
        <footnote id="F2">Shares are held by the Trust for the benefit of the reporting person's spouse and children. The reporting person's spouse is a trustee of the Trust.</footnote>
        <footnote id="F3">On November 13, 2023, the issuer acquired the private Delaware corporation which was then known as Cartesian Therapeutics, Inc. in accordance with the terms of an Agreement and Plan of Merger, dated November 13, 2023 (the &quot;Merger&quot;). These securities represent merger consideration payable as a result of the closing of the Merger and securities purchased in a private placement in November 2023.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew Bartholomae, Attorney-in-Fact for Murat Kalayoglu</signatureName>
        <signatureDate>2024-10-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
