<SEC-DOCUMENT>0000935836-25-000476.txt : 20250730
<SEC-HEADER>0000935836-25-000476.hdr.sgml : 20250730
<ACCEPTANCE-DATETIME>20250730182032
ACCESSION NUMBER:		0000935836-25-000476
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250728
FILED AS OF DATE:		20250730
DATE AS OF CHANGE:		20250730

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			EcoR1 Capital, LLC
		CENTRAL INDEX KEY:			0001587114
		ORGANIZATION NAME:           	
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37368
		FILM NUMBER:		251168504

	BUSINESS ADDRESS:	
		STREET 1:		357 TEHAMA STREET #3
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94103
		BUSINESS PHONE:		415-448-6534

	MAIL ADDRESS:	
		STREET 1:		357 TEHAMA STREET #3
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94103

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Adaptimmune Therapeutics PLC
		CENTRAL INDEX KEY:			0001621227
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			X0
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		ADDRESS IS A NON US LOCATION: 	YES
		STREET 1:		60 JUBILEE AVENUE
		STREET 2:		MILTON PARK
		CITY:			ABINGDON, OXFORDSHIRE
		PROVINCE COUNTRY:   	X0
		BUSINESS PHONE:		44 1235 430000

	MAIL ADDRESS:	
		ADDRESS IS A NON US LOCATION: 	YES
		STREET 1:		60 JUBILEE AVENUE
		STREET 2:		MILTON PARK
		CITY:			ABINGDON, OXFORDSHIRE
		PROVINCE COUNTRY:   	X0

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Adaptimmune Ltd
		DATE OF NAME CHANGE:	20141001
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-07-28</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001621227</issuerCik>
        <issuerName>Adaptimmune Therapeutics PLC</issuerName>
        <issuerTradingSymbol>ADAP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001587114</rptOwnerCik>
            <rptOwnerName>EcoR1 Capital, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>357 TEHAMA STREET #3</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2025-07-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>33931740</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.1125</value>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>130492680</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2025-07-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2687460</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.1012</value>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>127805220</value>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Ordinary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2025-07-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>27433338</value>
                    <footnoteId id="F9"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.1021</value>
                    <footnoteId id="F7"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>100371882</value>
                    <footnoteId id="F10"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These Ordinary Shares are held through American Depositary Shares (&quot;ADS&quot;) of the Issuer. Each ADS represents 6 Ordinary Shares.</footnote>
        <footnote id="F2">The reporting persons are EcoR1 Capital, LLC (&quot;Ecor1&quot;), Oleg Nodelman and EcoR1 Capital Fund Qualified, L.P. (&quot;Qualified Fund&quot;). EcoR1 is the general partner and investment adviser of private funds, including Qualified Fund (the &quot;Fund&quot;). Mr. Nodelman is the manager and controlling owner of EcoR1. EcoR1 is filing this Form 4 for itself, Mr. Nodelman and Qualified Fund. The filers are filing this Form 4 jointly, but not as a group, and each expressly disclaims membership in a group within the meaning of Rule 13d-5(b) under the Securities Exchange Act of 1934. The Funds hold these securities directly for the benefit of their investors. EcoR1 may be deemed to indirectly beneficially own them as the investment adviser to the Funds. Mr. Nodelman may be deemed to indirectly beneficially own them as the control person of EcoR1. The filers disclaim beneficial ownership of the securities except to the extent of their respective pecuniary interests therein.</footnote>
        <footnote id="F3">The reporting persons sold 5,655,290 ADSs representing 33,931,740 Ordinary Shares. Qualified Fund sold 5,281,476 of those ADSs, representing 31,688,856 Ordinary Shares.</footnote>
        <footnote id="F4">The price reported in Column 4 is the price per ADS sold by the reporting persons. This price is a weighted average price. These ADSs were sold in multiple transactions at prices ranging from $0.1086 to $0.1184, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission upon request, full information regarding the number of ADSs sold at each separate price within the ranges set forth in this footnote.</footnote>
        <footnote id="F5">After this transaction, the reporting persons beneficially owned 21,748,780 ADSs, including 20,569,634 ADS held by Qualified Fund representing 123,417,804 Ordinary Shares.</footnote>
        <footnote id="F6">The reporting persons sold 447,910 ADSs representing 2,687,460 Ordinary Shares. Qualified Fund sold 418,303 of those ADSs, representing 2,509,818 Ordinary Shares.</footnote>
        <footnote id="F7">The price reported in Column 4 is the price per ADS sold by the reporting persons.</footnote>
        <footnote id="F8">After this transaction, the reporting persons beneficially owned 21,300,870 ADSs, including 20,151,331 ADSs held by Qualified Fund representing 120,907,986 Ordinary Shares.</footnote>
        <footnote id="F9">The reporting persons sold 4,572,223 ADSs representing 27,433,338 Ordinary Shares. Qualified Fund sold 4,270,000 of those ADSs, representing 25,620,000 Ordinary Shares.</footnote>
        <footnote id="F10">After this transaction, the reporting persons beneficially owned 16,728,647 ADSs, including 15,881,331 ADSs held by Qualified Fund representing 95,287,986 Ordinary Shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Oleg Nodelman</signatureName>
        <signatureDate>2025-07-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
