<SEC-DOCUMENT>0001104659-25-055495.txt : 20250602
<SEC-HEADER>0001104659-25-055495.hdr.sgml : 20250602
<ACCEPTANCE-DATETIME>20250602164207
ACCESSION NUMBER:		0001104659-25-055495
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250530
FILED AS OF DATE:		20250602
DATE AS OF CHANGE:		20250602

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Wasman Jane
		CENTRAL INDEX KEY:			0001352455
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33958
		FILM NUMBER:		251015659

	MAIL ADDRESS:	
		STREET 1:		C/O ACORDA THERAPEUTICS, INC.
		STREET 2:		420 SAW MILL RIVER ROAD
		CITY:			ARDSLEY
		STATE:			NY
		ZIP:			10502

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
		EIN:				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>tm2516957-1_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-05-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001352455</rptOwnerCik>
            <rptOwnerName>Wasman Jane</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>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-05-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.69</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30400</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares were purchased in multiple transactions at a price of $1.69. The reporting person undertakes to provide SELLAS Life Sciences Group, Inc., any security holder of SELLAS Life Sciences Group, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at the price set forth in this footnote.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jane Wasman</signatureName>
        <signatureDate>2025-06-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
