<SEC-DOCUMENT>0001209191-21-035479.txt : 20210524
<SEC-HEADER>0001209191-21-035479.hdr.sgml : 20210524
<ACCEPTANCE-DATETIME>20210524175032
ACCESSION NUMBER:		0001209191-21-035479
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210521
FILED AS OF DATE:		20210524
DATE AS OF CHANGE:		20210524

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Parikh Asit
		CENTRAL INDEX KEY:			0001796787

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39094
		FILM NUMBER:		21956531

	MAIL ADDRESS:	
		STREET 1:		C/O PHATHOM PHARMACEUTICALS, INC.
		STREET 2:		2150 E. LAKE COOK ROAD, SUITE 800
		CITY:			BUFFALO GROVE
		STATE:			IL
		ZIP:			60089

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Phathom Pharmaceuticals, Inc.
		CENTRAL INDEX KEY:			0001783183
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				824151574
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 CAMPUS DRIVE,
		STREET 2:		SUITE 102
		CITY:			FLORHAM PARK
		STATE:			NJ
		ZIP:			07932
		BUSINESS PHONE:		(877) 742-8466

	MAIL ADDRESS:	
		STREET 1:		100 CAMPUS DRIVE,
		STREET 2:		SUITE 102
		CITY:			FLORHAM PARK
		STATE:			NJ
		ZIP:			07932
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-05-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001783183</issuerCik>
        <issuerName>Phathom Pharmaceuticals, Inc.</issuerName>
        <issuerTradingSymbol>PHAT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001796787</rptOwnerCik>
            <rptOwnerName>Parikh Asit</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PHATHOM PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>100 CAMPUS DRIVE, SUITE 102</rptOwnerStreet2>
            <rptOwnerCity>FLORHAM PARK</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07932</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>35.49</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-05-21</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2031-05-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option was granted pursuant to the Registrant's Non-Employee Director Compensation Program. The option shall vest and/or become exercisable on the first to occur of (A) the first anniversary of the date of grant or (B) the next occurring annual meeting of the Registrant's stockholders, subject to Reporting Person's continuing in service on the Board through such vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Larry Miller, Attorney-in-Fact for Asit Parikh</signatureName>
        <signatureDate>2021-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
