<SEC-DOCUMENT>0001104659-24-125944.txt : 20241205
<SEC-HEADER>0001104659-24-125944.hdr.sgml : 20241205
<ACCEPTANCE-DATETIME>20241205170619
ACCESSION NUMBER:		0001104659-24-125944
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241204
FILED AS OF DATE:		20241205
DATE AS OF CHANGE:		20241205

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CICIC DRAGAN
		CENTRAL INDEX KEY:			0001565795
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33958
		FILM NUMBER:		241529842

	MAIL ADDRESS:	
		STREET 1:		C/O ACTINIUM PHARMACEUTICALS, INC
		STREET 2:		546 FIFTH AVENUE, 14TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER NAME:	
		FORMER CONFORMED NAME:	CICIC DRAGON
		DATE OF NAME CHANGE:	20130102

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SELLAS Life Sciences Group, Inc.
		CENTRAL INDEX KEY:			0001390478
		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:		7 TIMES SQUARE
		STREET 2:		SUITE 2503
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036
		BUSINESS PHONE:		6462005278

	MAIL ADDRESS:	
		STREET 1:		7 TIMES SQUARE
		STREET 2:		SUITE 2503
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10036

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Galena Biopharma, Inc.
		DATE OF NAME CHANGE:	20110926

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RXi Pharmaceuticals Corp
		DATE OF NAME CHANGE:	20110926

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GALENA BIOPHARMA, INC.
		DATE OF NAME CHANGE:	20110922
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tm2430303-3_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-12-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001390478</issuerCik>
        <issuerName>SELLAS Life Sciences Group, Inc.</issuerName>
        <issuerTradingSymbol>SLS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001565795</rptOwnerCik>
            <rptOwnerName>CICIC DRAGAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SELLAS LIFE SCIENCES GROUP, INC.,</rptOwnerStreet1>
            <rptOwnerStreet2>7 TIMES SQUARE, SUITE 2503</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10036</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Chief Development Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-12-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8256</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>115328</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Transaction relates to shares of common stock withheld by the SELLAS Life Sciences Group, Inc. (the &quot;Issuer&quot;) to cover tax withholding obligations of the Reporting Person in connection with the vesting of Restricted Stock Units (&quot;RSUs&quot;).</footnote>
        <footnote id="F2">Represents the number shares of common stock withheld by the Issuer to cover tax withholding obligations of the Reporting Person in connection with the vesting of RSUs.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kostantinos Skordalos, Power of Attorney For: Dragan Cicic</signatureName>
        <signatureDate>2024-12-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
