<SEC-DOCUMENT>0001209191-22-035209.txt : 20220608
<SEC-HEADER>0001209191-22-035209.hdr.sgml : 20220608
<ACCEPTANCE-DATETIME>20220608190702
ACCESSION NUMBER:		0001209191-22-035209
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20220606
FILED AS OF DATE:		20220608
DATE AS OF CHANGE:		20220608

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MATSUI CONNIE
		CENTRAL INDEX KEY:			0001236537

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38662
		FILM NUMBER:		221004576

	MAIL ADDRESS:	
		STREET 1:		3030 CALLAN RD
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SUTRO BIOPHARMA, INC.
		CENTRAL INDEX KEY:			0001382101
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				452441988
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		111 OYSTER POINT BLVD.
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080
		BUSINESS PHONE:		650-392-8412

	MAIL ADDRESS:	
		STREET 1:		111 OYSTER POINT BLVD.
		CITY:			SOUTH SAN FRANCISCO
		STATE:			CA
		ZIP:			94080

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SUTRO BIOPHARMA INC
		DATE OF NAME CHANGE:	20061127
</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>2022-06-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001382101</issuerCik>
        <issuerName>SUTRO BIOPHARMA, INC.</issuerName>
        <issuerTradingSymbol>STRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001236537</rptOwnerCik>
            <rptOwnerName>MATSUI CONNIE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SUTRO BIOPHARMA, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>111 OYSTER POINT BLVD.</rptOwnerStreet2>
            <rptOwnerCity>SOUTH SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94080</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>4.44</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2022-06-06</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>18500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2032-06-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>18500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option vests as to 8.33% of the total shares monthly, commencing July 6, 2022, with 100% of the total shares vested and exercisable on the earlier of the issuer's 2023 annual stockholders meeting or June 6, 2023,  subject to the reporting person's provision of service to the issuer on each vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Edward C. Albini as attorney-in-fact</signatureName>
        <signatureDate>2022-06-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
