<SEC-DOCUMENT>0001453687-24-000138.txt : 20241121
<SEC-HEADER>0001453687-24-000138.hdr.sgml : 20241121
<ACCEPTANCE-DATETIME>20241121185012
ACCESSION NUMBER:		0001453687-24-000138
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241120
FILED AS OF DATE:		20241121
DATE AS OF CHANGE:		20241121

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Jewell Christopher M
		CENTRAL INDEX KEY:			0002000226
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37798
		FILM NUMBER:		241485958

	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:		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_1732233005.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-11-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002000226</rptOwnerCik>
            <rptOwnerName>Jewell Christopher M</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>Chief Scientific Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common  Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-11-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>14000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.23</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>39940</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>3.23</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-11-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>14000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2033-01-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common  Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>76432</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option is currently exercisable for 123,235 shares of Common Stock and becomes exercisable for an additional 2,969 shares of Common Stock each month until it is fully exercisable on June 16, 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 the Issuer's Series A Preferred Stock in connection with the merger. On April 8, 2024, these options previously exercisable for shares of Series A Preferred Stock became exercisable solely for shares of the Issuer's Common Stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Matthew Bartholomae, Attorney-in-Fact for Christopher Jewell</signatureName>
        <signatureDate>2024-11-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
