<SEC-DOCUMENT>0001144204-18-033605.txt : 20180608
<SEC-HEADER>0001144204-18-033605.hdr.sgml : 20180608
<ACCEPTANCE-DATETIME>20180608172402
ACCESSION NUMBER:		0001144204-18-033605
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180606
FILED AS OF DATE:		20180608
DATE AS OF CHANGE:		20180608

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KLEMP WALTER V
		CENTRAL INDEX KEY:			0000938419

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37758
		FILM NUMBER:		18890444

	MAIL ADDRESS:	
		STREET 1:		1415 WEST LOOP NORTH
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77055

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Moleculin Biotech, Inc.
		CENTRAL INDEX KEY:			0001659617
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				474671999
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2575 WEST BELLFORT
		STREET 2:		SUITE 333
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77054
		BUSINESS PHONE:		713-300-5160

	MAIL ADDRESS:	
		STREET 1:		2575 WEST BELLFORT
		STREET 2:		SUITE 333
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77054
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tv496089_4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001659617</issuerCik>
        <issuerName>Moleculin Biotech, Inc.</issuerName>
        <issuerTradingSymbol>MBRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000938419</rptOwnerCik>
            <rptOwnerName>KLEMP WALTER V</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MOLECULIN BIOTECH, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2575 WEST BELLFORT, SUITE 333</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77054</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO and President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.82</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-06-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>603000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-06-06</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>603000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>943000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The stock option set forth in this table vests in four equal annual installments beginning on the first anniversary of the Transaction Date, subject to the grantee's continued service to the Company on each vesting date.</footnote>
        <footnote id="F2">Issued in connection with the reporting person's employment with the Company.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Walter Klemp</signatureName>
        <signatureDate>2018-06-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
