<SEC-DOCUMENT>0001567619-21-018719.txt : 20211026
<SEC-HEADER>0001567619-21-018719.hdr.sgml : 20211026
<ACCEPTANCE-DATETIME>20211026162958
ACCESSION NUMBER:		0001567619-21-018719
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211024
FILED AS OF DATE:		20211026
DATE AS OF CHANGE:		20211026

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROWLAND LLOYD A
		CENTRAL INDEX KEY:			0001236395

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37587
		FILM NUMBER:		211348944

	MAIL ADDRESS:	
		STREET 1:		AMYLIN PHARMACEUTICALS INC
		STREET 2:		9360 TOWNE CENTRE DR
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CytomX Therapeutics, Inc.
		CENTRAL INDEX KEY:			0001501989
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				273521219
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		151 OYSTER POINT BLVD.
		STREET 2:		SUITE 400
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		650.515.3185

	MAIL ADDRESS:	
		STREET 1:		151 OYSTER POINT BLVD.
		STREET 2:		SUITE 400
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-10-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001501989</issuerCik>
        <issuerName>CytomX Therapeutics, Inc.</issuerName>
        <issuerTradingSymbol>CTMX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001236395</rptOwnerCik>
            <rptOwnerName>ROWLAND LLOYD A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CYTOMX THERAPEUTICS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>151 OYSTER POINT BLVD., STE. 400</rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94080</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.34</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-10-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-10-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>40000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Stock Units (PSUs)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-10-24</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>30000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">1/48th of the shares subject to the option vest on each monthly anniversary measured from October 24, 2021 (the &quot;Vesting Commencement Date&quot;), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued service to the Issuer through each such date.</footnote>
        <footnote id="F2">Each Performance Stock Unit (&quot;PSU&quot;) represents a contingent right to receive one share of the Issuer's Common Stock upon vesting. 50% of the PSUs vest upon achievement of a certain performance-based milestone within 1 year from grant date and 50% of the PSUs vest upon achievement of a certain performance-based milestone within 2 years from grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Lloyd Rowland</signatureName>
        <signatureDate>2021-10-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
