<SEC-DOCUMENT>0001209191-23-032542.txt : 20230526
<SEC-HEADER>0001209191-23-032542.hdr.sgml : 20230526
<ACCEPTANCE-DATETIME>20230526162200
ACCESSION NUMBER:		0001209191-23-032542
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230525
FILED AS OF DATE:		20230526
DATE AS OF CHANGE:		20230526

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Countouriotis Athena
		CENTRAL INDEX KEY:			0001571469

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39231
		FILM NUMBER:		23969272

	MAIL ADDRESS:	
		STREET 1:		C/O AMBIT BIOSCIENCES CORPORATION
		STREET 2:		11080 ROSELLE STREET
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Passage BIO, Inc.
		CENTRAL INDEX KEY:			0001787297
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				822729751
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE COMMERCE SQUARE
		STREET 2:		2005 MARKET STREET, 39TH FLOOR
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103
		BUSINESS PHONE:		2678660312

	MAIL ADDRESS:	
		STREET 1:		ONE COMMERCE SQUARE
		STREET 2:		2005 MARKET STREET, 39TH FLOOR
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0407</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-05-25</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001787297</issuerCik>
        <issuerName>Passage BIO, Inc.</issuerName>
        <issuerTradingSymbol>PASG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001571469</rptOwnerCik>
            <rptOwnerName>Countouriotis Athena</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE COMMERCE SQUARE</rptOwnerStreet1>
            <rptOwnerStreet2>2005 MARKET STREET, 39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>PHILADELPHIA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.00</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2023-05-25</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>24000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2033-05-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The stock option vests in full on the earlier of:  (i) the one year anniversary of the grant date or (ii) the date of the issuer's 2024 Annual Meeting of its stockholders, subject to the reporting person's continuous service to the issuer on such date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Edgar Cale, Attorney-in-Fact</signatureName>
        <signatureDate>2023-05-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
