<SEC-DOCUMENT>0001171843-26-002894.txt : 20260430
<SEC-HEADER>0001171843-26-002894.hdr.sgml : 20260430
<ACCEPTANCE-DATETIME>20260430160048
ACCESSION NUMBER:		0001171843-26-002894
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260429
FILED AS OF DATE:		20260430
DATE AS OF CHANGE:		20260430

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lerner Neil
		CENTRAL INDEX KEY:			0001505148
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39696
		FILM NUMBER:		26924788

	MAIL ADDRESS:	
		STREET 1:		C/O PSYCHEMEDICS CORPORATION
		STREET 2:		125 NAGOG PARK
		CITY:			ACTON
		STATE:			MA
		ZIP:			01720

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Compass Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001738021
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		80 GUEST STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02135
		BUSINESS PHONE:		617-500-8099

	MAIL ADDRESS:	
		STREET 1:		80 GUEST STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02135

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Olivia Ventures, Inc.
		DATE OF NAME CHANGE:	20180419
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2026-04-29</periodOfReport>

    <dateOfOriginalSubmission>2026-04-29</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001738021</issuerCik>
        <issuerName>Compass Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>CMPX</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001505148</rptOwnerCik>
            <rptOwnerName>Lerner Neil</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>C/O COMPASS THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>80 GUEST STREET, SUITE 601</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02135</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Accounting Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-04-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.89</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>397500</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">62,500 of the shares represents unvested restricted stock units (&quot;RSU&quot;) granted on January 2, 2026. Each RSU represents a contingent right to receive one share of common stock. The award is subject to service-based vesting conditions and vests in four equal annual installments, with the first installment vested on January 2, 2027.</footnote>
    </footnotes>

    <remarks>Explanatory Note: This amendment is being filed to correct the transaction code reported in Table I of the original Form 4 filed on April 29, 2026. The transaction was inadvertently reported using transaction code A. The correct transaction code is P, which reflects that the transaction was an open market purchase. All other information in the original filing remains unchanged.</remarks>

    <ownerSignature>
        <signatureName>/s/ Neil Lerner</signatureName>
        <signatureDate>2026-04-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
