<SEC-DOCUMENT>0001104659-24-125943.txt : 20241205
<SEC-HEADER>0001104659-24-125943.hdr.sgml : 20241205
<ACCEPTANCE-DATETIME>20241205170544
ACCESSION NUMBER:		0001104659-24-125943
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20241204
FILED AS OF DATE:		20241205
DATE AS OF CHANGE:		20241205

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Stergiou Angelos M.
		CENTRAL INDEX KEY:			0001724253
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33958
		FILM NUMBER:		241529838

	MAIL ADDRESS:	
		STREET 1:		C/O SELLAS LIFE SCIENCES GROUP, INC.
		STREET 2:		2000 CROW CANYON PLACE, SUITE 380
		CITY:			SAN RAMON
		STATE:			CA
		ZIP:			94583

	FORMER NAME:	
		FORMER CONFORMED NAME:	Stergiou Andelos M.
		DATE OF NAME CHANGE:	20171205

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>
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<TYPE>4
<SEQUENCE>1
<FILENAME>tm2430303-2_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>0001724253</rptOwnerCik>
            <rptOwnerName>Stergiou Angelos M.</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>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</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>28289</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>358132</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>

    <remarks>Exhibit List - Exhibit 24 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Angelos M. Stergiou</signatureName>
        <signatureDate>2024-12-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
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<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>tm2430303d2_ex24.htm
<DESCRIPTION>EXHIBIT 24
<TEXT>
<HTML>
<HEAD>
     <TITLE></TITLE>
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<BODY STYLE="font: 10pt Times New Roman, Times, Serif">

<P STYLE="margin: 0">&nbsp;</P>

<P STYLE="margin: 0; text-align: right"><B>Exhibit 24</B></P>

<P STYLE="margin: 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>POWER OF ATTORNEY</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">Know all by these present, that the undersigned
hereby constitutes and appoints each of&nbsp;John T. Burns and&nbsp;Stacy E. Yeung&nbsp;of SELLAS Life Sciences Group,&nbsp;Inc. (the
 &ldquo;Company&rdquo;) and&nbsp;Daniel Bagliebter,&nbsp;Kostantinos Skordalos,&nbsp;Charles Richard Lampkins,&nbsp;Maura Foley, Robyn
Frattali and&nbsp;Erber Hernandez&nbsp;of&nbsp;Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., signing singly, with full power of
substitution, the undersigned&rsquo;s true and lawful attorney-in-fact to:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 1in">(1)&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;execute
and deliver for and on behalf of the undersigned, forms and authentication documents for EDGAR Filing Access;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 1in">(2)&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;do and
perform any and all acts for and on behalf of the undersigned which may be necessary or desirable to complete and execute any such forms
and authentication documents;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 1in">(3)&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;execute
and deliver for and on behalf of the undersigned, in the undersigned&rsquo;s capacity as an officer, director and/or 10% shareholder of
the Company, Forms 3, 4 and 5 in accordance with Section&nbsp;16(a)&nbsp;of the Securities Exchange Act of 1934 and the rules&nbsp;thereunder;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 1in">(4)&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;do and
perform any and all acts for and on behalf of the undersigned which may be necessary or desirable to complete and execute any such Form&nbsp;3,
4 or 5 and timely file such form with the United States Securities and Exchange Commission and any stock exchange, self-regulatory or
similar authority; and</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 1in">(5)&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;&#8239;take
any other action of any type whatsoever in connection with the foregoing which, in the opinion of such attorney-in-fact, may be of benefit
to, in the best interests of, or legally required by the undersigned, it being understood that the documents executed by such attorney-in-fact
on behalf of the undersigned pursuant to this Power of Attorney shall be in such form and shall contain such terms and conditions as such
attorney-in-fact may approve in such attorney-in-fact&rsquo;s discretion.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">The undersigned hereby grants to each such attorney-in-fact
full power and authority to do and perform any and every act and thing whatsoever requisite, necessary, or proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all intents and purposes as the undersigned might or could do if personally
present, with full power of substitution or revocation, hereby ratifying and confirming all that such attorney-in-fact, or such attorney-in-fact&rsquo;s
substitute or substitutes, shall lawfully do or cause to be done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in serving in such capacity at the request of the undersigned,
are not assuming, nor is the Company assuming, (i)&nbsp;any of the undersigned's responsibilities to comply with the requirements of the
Exchange Act or any liability for the undersigned&rsquo;s failure to comply with such requirements or (ii)&nbsp;any obligation or liability
that the undersigned incurs for profit disgorgement under Section&nbsp;16(b)&nbsp;of the Securities Exchange Act of 1934, as amended.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">This Power of Attorney shall remain in full force
and effect until the undersigned is no longer required to file Forms 3, 4 and 5 with respect to the undersigned&rsquo;s holdings of and
transactions in securities issued by the Company, unless earlier revoked by the undersigned in a signed writing delivered to the foregoing
attorneys-in-fact.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">This Power of Attorney does not revoke any other
power of attorney that the undersigned has previously granted.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">IN WITNESS WHEREOF, the undersigned has caused
this Power of Attorney to be executed as of the date written below.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Date: 12/05/2024</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
  <TR STYLE="vertical-align: bottom">
    <TD STYLE="width: 50%; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="width: 50%; border-bottom: black 1pt solid; font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">/s/ Angelos M. Stergiou, M.D., Sc.D. h.c.</FONT></TD></TR>
  <TR STYLE="vertical-align: bottom">
    <TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Name: Angelos M. Stergiou, M.D., Sc.D. h.c.</FONT></TD></TR>
  </TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

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