<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2017-09-27</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001654151</issuerCik>
        <issuerName>Deciphera Pharmaceuticals, Inc.</issuerName>
        <issuerTradingSymbol>DCPH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001714870</rptOwnerCik>
            <rptOwnerName>Rosen Oliver</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DECIPHERA PHARMACEUTICALS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>500 TOTTEN POND ROAD</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02451</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Medical Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.89</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-12-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>207614</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.89</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-12-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>46137</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>3.95</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-09-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>48025</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.13</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-06-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>45883</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This stock option award was issued pursuant to Deciphera Pharmaceuticals, LLC's 2015 Equity Incentive Plan.  The option vests in 16 equal quarterly installments at the end of each quarter following the vesting commencement date of June 6, 2014, subject to continued service through such dates.</footnote>
        <footnote id="F2">These options are currently options to purchase shares of common stock of Deciphera Pharmaceuticals, LLC, a wholly-owned subsidiary of the Issuer, and will be exchanged for options of the Issuer on a 1 to 5.65 basis immediately prior to the closing of the initial public offering of the Issuer (the &quot;Exchange&quot;) pursuant to that certain Reorganization Agreement and Plan of Merger by and among the Issuer, Deciphera Pharmaceuticals, LLC and the other parties named therein, dated September 26, 2017 (the &quot;Merger Agreement&quot;). The amount in this Column 3 reflects the options that will be outstanding following the Exchange.</footnote>
        <footnote id="F3">This stock option award was issued pursuant to Deciphera Pharmaceuticals, LLC's 2015 Equity Incentive Plan.  The option vests in 48 equal monthly installments at the end of each month following the vesting commencement date of September 30, 2015, subject to continued service through such dates.</footnote>
        <footnote id="F4">This stock option award was issued pursuant to Deciphera Pharmaceuticals, LLC's 2015 Equity Incentive Plan.  The option vests in 48 equal monthly installments at the end of each month following the vesting commencement date of July 1, 2016, subject to continued service through such dates.</footnote>
        <footnote id="F5">This stock option award was issued pursuant to Deciphera Pharmaceuticals, LLC's 2015 Equity Incentive Plan.  The option vests in 48 equal monthly installments at the end of each month following the vesting commencement date of May 26, 2017, subject to continued service through such dates.</footnote>
    </footnotes>

    <remarks>Power of Attorney - Exhibit 24 attached</remarks>

    <ownerSignature>
        <signatureName>/s/ Jeffrey M. Held, Attorney-in-Fact</signatureName>
        <signatureDate>2018-09-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
