<SEC-DOCUMENT>0001193125-26-117653.txt : 20260320
<SEC-HEADER>0001193125-26-117653.hdr.sgml : 20260320
<ACCEPTANCE-DATETIME>20260320161338
ACCESSION NUMBER:		0001193125-26-117653
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20260318
FILED AS OF DATE:		20260320
DATE AS OF CHANGE:		20260320

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Mellish Martin C.B.
		CENTRAL INDEX KEY:			0001992320
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38215
		FILM NUMBER:		26778383

	MAIL ADDRESS:	
		STREET 1:		13 BERRILL FARMS LN
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NuCana plc
		CENTRAL INDEX KEY:			0001709626
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			X0
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3 LOCHSIDE WAY
		CITY:			EDINBURGH
		STATE:			X0
		ZIP:			EH12 9DT
		BUSINESS PHONE:		44-0-131-357-1111

	MAIL ADDRESS:	
		STREET 1:		3 LOCHSIDE WAY
		CITY:			EDINBURGH
		STATE:			X0
		ZIP:			EH12 9DT

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NuCana BioMed Ltd
		DATE OF NAME CHANGE:	20170619
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>3
<TEXT>
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<ownershipDocument>

    <schemaVersion>X0607</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2026-03-18</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001709626</issuerCik>
        <issuerName>NuCana plc</issuerName>
        <issuerTradingSymbol>NCNA</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001992320</rptOwnerCik>
            <rptOwnerName>Mellish Martin C.B.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NUCANA PLC</rptOwnerStreet1>
            <rptOwnerStreet2>3 LOCHSIDE WAY</rptOwnerStreet2>
            <rptOwnerCity>EDINBURGH</rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode>EH12 9DT</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Ordinary Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
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    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>American Depositary Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
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            <exerciseDate>
                <footnoteId id="F1"/>
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                <value>Options</value>
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                    <value>35231753</value>
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                    <value>42362799</value>
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    <footnotes>
        <footnote id="F1">Each American Depositary Share (&quot;ADS&quot;) represents 5,000 ordinary shares, nominal value 0.0004 Pounds Sterling per share (the &quot;Ordinary Shares&quot;), of NuCana plc (the &quot;Company&quot;). ADSs have no expiration date.</footnote>
        <footnote id="F2">The Ordinary Shares underlying this option have an exercise price of 0.004 Pounds Sterling, completed vesting on June 20, 2025 and expire June 20, 2035.</footnote>
        <footnote id="F3">The Ordinary Shares underlying this option have an exercise price of 0.0004 Pounds Sterling and will vest in full on June 20, 2026, subject to the Reporting Person's continued service with the Company through the applicable vesting date.</footnote>
        <footnote id="F4">The Ordinary Shares underlying this option have an exercise price of 0.0005 Pounds Sterling, completed vesting on January 14, 2026 and expire January 14, 2036.</footnote>
        <footnote id="F5">The Ordinary Shares underlying this option have an exercise price of 0.0004 Pounds Sterling and will vest in full on January 14, 2027, subject to the Reporting Person's continued service with the Company through the applicable vesting date.</footnote>
    </footnotes>

    <remarks>This Form 3 is being filed late due to unanticipated delays in receiving the Reporting Person's EDGAR codes, which delays the Reporting Person understands were due to the high volume of applications at the time.

Exhibit 24.1 - Power of Attorney</remarks>

    <ownerSignature>
        <signatureName>/s/ Ian Webster,  Attorney-in-Fact for Martin Mellish</signatureName>
        <signatureDate>2026-03-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
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<DOCUMENT>
<TYPE>EX-24.1
<SEQUENCE>2
<FILENAME>ck0001709626-ex24_1.htm
<DESCRIPTION>EX-24.1
<TEXT>
<!-- DFIN ActiveDisclosure (SM) HTML Document - http://www.dfinsolutions.com/ --><!-- Creation Date :2026-03-20T13:15:46.3837+00:00 --><!-- Copyright (c) 2026 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <title>EX-24.1</title>
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  <div style="padding-top:0.5in;z-index:2;min-height:1in;position:relative;box-sizing:border-box;"><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;margin-left:0;margin-right:0;"><font style="white-space:pre-wrap;font-size:12pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p></div>
  <div class="main-content-container" style="z-index:5;position:relative;"><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:center;"><font style="color:#000000;white-space:pre-wrap;font-weight:bold;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">POWER OF ATTORNEY</font></p><p style="text-indent:6.667%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">Know all by these presents, that the undersigned hereby constitutes and appoints each of Hugh Griffith and Ian Webster, the Chief Executive Officer and Interim Chief Financial Officer, respectively, of NuCana plc (the &#x201c;Company&#x201d;), and John T. Rudy, Allyson Wilkinson, Gianna M. Nappi, Michelle St Francis, Robyn M. Frattali and Autumn N. Mays of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., signing singly, with full power of substitution, the undersigned&#x2019;s true and lawful attorney-in-fact to:</font></p><div class="item-list-element-wrapper" style="margin-left:6.667%;display:flex;margin-top:0;justify-content:flex-start;align-items:baseline;margin-bottom:0;margin-right:9.333%;min-width:6.667%;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:7.14323979728499%;word-break:keep-all;display:inline-flex;justify-content:flex-start;">(1)</font><div style="display:inline;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">execute for and on behalf of the undersigned, in the undersigned&#x2019;s capacity as a director of the Company, forms and authentication documents for EDGAR Filing Access;</font></div></div><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;margin-right:9.333%;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><div class="item-list-element-wrapper" style="margin-left:6.667%;display:flex;margin-top:0;justify-content:flex-start;align-items:baseline;margin-bottom:0;margin-right:9.333%;min-width:6.667%;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:7.14323979728499%;word-break:keep-all;display:inline-flex;justify-content:flex-start;">(2)</font><div style="display:inline;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">do and perform any and all acts for and on behalf of the undersigned that may be necessary or desirable to complete and execute any such forms and authentication documents;</font></div></div><p style="margin-left:13.333%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;margin-right:9.333%;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><div class="item-list-element-wrapper" style="margin-left:6.667%;display:flex;margin-top:0;justify-content:flex-start;align-items:baseline;margin-bottom:0;margin-right:9.333%;min-width:6.667%;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:7.14323979728499%;word-break:keep-all;display:inline-flex;justify-content:flex-start;">(3)</font><div style="display:inline;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">execute for and on behalf of the undersigned, in the undersigned&#x2019;s capacity as a director of the Company, Forms 3, 4 and 5 in accordance with Section 16(a) of the Securities Exchange Act of 1934, as amended, and the rules thereunder;</font></div></div><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;margin-right:9.333%;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><div class="item-list-element-wrapper" style="margin-left:6.667%;display:flex;margin-top:0;justify-content:flex-start;align-items:baseline;margin-bottom:0;margin-right:9.333%;min-width:6.667%;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:7.14323979728499%;word-break:keep-all;display:inline-flex;justify-content:flex-start;">(4)</font><div style="display:inline;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">do and perform any and all acts for and on behalf of the undersigned that may be necessary or desirable to complete and execute any such Form 3, 4 or 5 and timely file such form with the United States Securities and Exchange Commission and any stock exchange or similar authority; and</font></div></div><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;margin-right:9.333%;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><div class="item-list-element-wrapper" style="margin-left:6.667%;display:flex;margin-top:0;justify-content:flex-start;align-items:baseline;margin-bottom:0;margin-right:9.333%;min-width:6.667%;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:7.14323979728499%;word-break:keep-all;display:inline-flex;justify-content:flex-start;">(5)</font><div style="display:inline;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">take any other action of any type whatsoever in connection with the foregoing that, 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&#x2019;s discretion.</font></div></div><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;margin-right:9.333%;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p><p style="text-indent:6.667%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">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&#x2019;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, any of the undersigned&#x2019;s responsibilities to comply with Section 16 of the Securities Exchange Act of 1934, as amended.</font></p><p style="text-indent:6.667%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">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&#x2019;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.</font></p></div>
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  <div style="padding-top:0.5in;z-index:2;min-height:1in;position:relative;box-sizing:border-box;"><p style="font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;margin-left:0;margin-right:0;"><font style="white-space:pre-wrap;font-size:12pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p></div>
  <div class="main-content-container" style="z-index:5;position:relative;"><p style="text-indent:6.667%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:justify;"><font style="color:#000000;white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be executed as of the date set forth below.</font></p><p style="text-indent:6.667%;font-size:10pt;margin-top:0;font-family:Times New Roman;margin-bottom:12pt;text-align:justify;"><font style="white-space:pre-wrap;font-size:11pt;font-family:Times New Roman;font-kerning:none;min-width:fit-content;">&#160;</font></p>
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     <td style="padding-top:0in;padding-left:0.075in;vertical-align:top;padding-bottom:0in;padding-right:0.075in;"><p style="font-size:11pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-kerning:none;min-width:fit-content;">By: </font><font style="color:#000000;white-space:pre-wrap;text-decoration:underline solid;font-kerning:none;min-width:fit-content;">/s/ Martin Mellish</font></p><p style="margin-left:4.667%;font-size:11pt;margin-top:0;font-family:Times New Roman;margin-bottom:0;text-align:left;"><font style="color:#000000;white-space:pre-wrap;font-kerning:none;min-width:fit-content;">Name: Martin Mellish</font></p></td>
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