<SEC-DOCUMENT>0001209191-20-042292.txt : 20200713
<SEC-HEADER>0001209191-20-042292.hdr.sgml : 20200713
<ACCEPTANCE-DATETIME>20200713165020
ACCESSION NUMBER:		0001209191-20-042292
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200713
FILED AS OF DATE:		20200713
DATE AS OF CHANGE:		20200713

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Branning Todd P.
		CENTRAL INDEX KEY:			0001765274

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39094
		FILM NUMBER:		201025648

	MAIL ADDRESS:	
		STREET 1:		C/O AMNEAL PHARMACEUTICLAS, INC.
		STREET 2:		400 CROSSING BOULEVARD
		CITY:			BRIDGEWATER
		STATE:			NJ
		ZIP:			08807

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>2020-07-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001765274</rptOwnerCik>
            <rptOwnerName>Branning Todd P.</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>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.43</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-07-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>85000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2030-07-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>85000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>85000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option will vest with respect to one-fourth of the shares of common stock on July 13, 2021, and will vest with respect to the remaining shares in equal monthly installments over the following three years, subject to the reporting person's continuous service to the Company on the applicable vesting dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Larry Miller, Attorney-in-Fact for Todd Branning</signatureName>
        <signatureDate>2020-07-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
