<SEC-DOCUMENT>0001104659-21-146421.txt : 20211203
<SEC-HEADER>0001104659-21-146421.hdr.sgml : 20211203
<ACCEPTANCE-DATETIME>20211203171333
ACCESSION NUMBER:		0001104659-21-146421
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211202
FILED AS OF DATE:		20211203
DATE AS OF CHANGE:		20211203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Burns John Thomas
		CENTRAL INDEX KEY:			0001568734

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33958
		FILM NUMBER:		211471095

	MAIL ADDRESS:	
		STREET 1:		16760 SW UPPER BOONES FERRY RD
		STREET 2:		SUITE 101
		CITY:			PORTLAND
		STATE:			X1
		ZIP:			97224

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SELLAS Life Sciences Group, Inc.
		CENTRAL INDEX KEY:			0001390478
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		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>tm2134552-4_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-12-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001568734</rptOwnerCik>
            <rptOwnerName>Burns John Thomas</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>VP, Finance &amp; Corp Controller</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-12-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>231</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.2673</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17644</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the number shares of common stock required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs.  The sale was to satisfy tax withholding obligations to be funded by a &quot;sell to cover&quot; transaction and does not represent a discretionary transaction by the Reporting Person.</footnote>
        <footnote id="F2">The price reflects the weighted average sale price of the shares of common stock sold. These shares of common stock were sold in multiple transactions at prices ranging from $6.25 to $6.27, inclusive, per share of common stock. The Reporting Person undertakes to provide, upon request by the SEC staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares of common stock sold at each price.</footnote>
    </footnotes>

    <remarks>Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.</remarks>

    <ownerSignature>
        <signatureName>/s/ John Burns</signatureName>
        <signatureDate>2021-12-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
