<SEC-DOCUMENT>0001599298-24-000006.txt : 20240104
<SEC-HEADER>0001599298-24-000006.hdr.sgml : 20240104
<ACCEPTANCE-DATETIME>20240104161645
ACCESSION NUMBER:		0001599298-24-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240102
FILED AS OF DATE:		20240104
DATE AS OF CHANGE:		20240104

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DUGGAN ROBERT W
		CENTRAL INDEX KEY:			0001055919
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36866
		FILM NUMBER:		24512130

	MAIL ADDRESS:	
		STREET 1:		611 SOUTH FORT HARRISON AVE
		STREET 2:		SUITE 306
		CITY:			CLEARWATER
		STATE:			FL
		ZIP:			33756

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Summit Therapeutics Inc.
		CENTRAL INDEX KEY:			0001599298
		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:		2882 SAND HILL ROAD
		STREET 2:		SUITE 106
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025
		BUSINESS PHONE:		617-514-7149

	MAIL ADDRESS:	
		STREET 1:		2882 SAND HILL ROAD
		STREET 2:		SUITE 106
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Summit Therapeutics plc
		DATE OF NAME CHANGE:	20150219

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Summit Corp plc
		DATE OF NAME CHANGE:	20140205
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1704402965.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-01-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001599298</issuerCik>
        <issuerName>Summit Therapeutics Inc.</issuerName>
        <issuerTradingSymbol>SMMT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001055919</rptOwnerCik>
            <rptOwnerName>DUGGAN ROBERT W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SUMMIT THERAPEUTICS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2882 SAND HILL ROAD, SUITE 106</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Co-Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.64</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-01-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>74545</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.32</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2034-01-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>74545</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>74545</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option was granted on January 2, 2024. The shares underlying the option shall vest in four equal quarterly installments on March 31, June 30, September 30 and December 31 following election, subject to the reporting person remaining as a non-salaried director on each such vesting date.</footnote>
        <footnote id="F2">The option was issued to the reporting person pursuant to the issuer's Director Retainer Option Election Plan in lieu of retainer fees of $98,400.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Ankur Dhingra, as Attorney-in-Fact for Robert W. Duggan</signatureName>
        <signatureDate>2024-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
