<SEC-DOCUMENT>0001770137-19-000002.txt : 20190321
<SEC-HEADER>0001770137-19-000002.hdr.sgml : 20190321
<ACCEPTANCE-DATETIME>20190320190606
ACCESSION NUMBER:		0001770137-19-000002
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		<ITEMS>06b
FILED AS OF DATE:		20190321
DATE AS OF CHANGE:		20190320
EFFECTIVENESS DATE:		20190321

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CASTLE BIOSCIENCES INC
		CENTRAL INDEX KEY:			0001447362
		IRS NUMBER:				770701744
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-332878
		FILM NUMBER:		19695644

	BUSINESS ADDRESS:	
		STREET 1:		2014 SAN MIGUEL DR
		CITY:			FRIENDSWOOD
		STATE:			TX
		ZIP:			77546
		BUSINESS PHONE:		281-796-9032

	MAIL ADDRESS:	
		STREET 1:		2014 SAN MIGUEL DR
		CITY:			FRIENDSWOOD
		STATE:			TX
		ZIP:			77546
</SEC-HEADER>
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        <entityName>CASTLE BIOSCIENCES INC</entityName>
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            <city>FRIENDSWOOD</city>
            <stateOrCountry>TX</stateOrCountry>
            <stateOrCountryDescription>TEXAS</stateOrCountryDescription>
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            <relatedPersonName>
                <firstName>Derek</firstName>
                <lastName>Maetzold</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Castle Biosciences, Inc.</street1>
                <street2>2014 San Miguel Drive</street2>
                <city>Friendswood</city>
                <stateOrCountry>TX</stateOrCountry>
                <stateOrCountryDescription>TEXAS</stateOrCountryDescription>
                <zipCode>77546</zipCode>
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            <relatedPersonRelationshipList>
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                <relationship>Director</relationship>
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            <relationshipClarification></relationshipClarification>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Mara</firstName>
                <lastName>Aspinall</lastName>
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                <street1>c/o Castle Biosciences, Inc.</street1>
                <street2>2014 San Miguel Drive</street2>
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                <stateOrCountryDescription>TEXAS</stateOrCountryDescription>
                <zipCode>77546</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Bonnie</firstName>
                <lastName>Anderson</lastName>
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                <firstName>Daniel</firstName>
                <middleName>M.</middleName>
                <lastName>Bradbury</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o BioBrit, LLC</street1>
                <street2>5462 Soledad Road</street2>
                <city>La Jolla</city>
                <stateOrCountry>CA</stateOrCountry>
                <stateOrCountryDescription>CALIFORNIA</stateOrCountryDescription>
                <zipCode>92037</zipCode>
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                <firstName>Joseph</firstName>
                <middleName>C.</middleName>
                <lastName>Cook, Jr.</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o MGC Venture Partners 2013, L.P.</street1>
                <street2>3835 Cleghorn Avenue, Suite 300</street2>
                <city>Nashville</city>
                <stateOrCountry>TN</stateOrCountry>
                <stateOrCountryDescription>TENNESSEE</stateOrCountryDescription>
                <zipCode>37215</zipCode>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>David</firstName>
                <lastName>Kabakoff, Ph.D.</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Sofinnova HealthQuest Partners, L.P.</street1>
                <street2>1301 Shoreway Road, Suite 350</street2>
                <city>Belmont</city>
                <stateOrCountry>CA</stateOrCountry>
                <stateOrCountryDescription>CALIFORNIA</stateOrCountryDescription>
                <zipCode>94002</zipCode>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Frank</firstName>
                <lastName>Stokes</lastName>
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                <street1>c/o Castle Biosciences, Inc.</street1>
                <street2>2014 San Miguel Drive</street2>
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                <zipCode>77546</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Bernhard</firstName>
                <middleName>E.</middleName>
                <lastName>Spiess</lastName>
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                <street1>c/o Castle Biosciences, Inc.</street1>
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                <firstName>Federico</firstName>
                <lastName>Monzon, M.D., FCAP</lastName>
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                <street1>c/o Castle Biosciences, Inc.</street1>
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                <lastName>Cole</lastName>
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    <offeringData>
        <industryGroup>
            <industryGroupType>Biotechnology</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06b</item>
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        <typeOfFiling>
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                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0001755120-19-000001</previousAccessionNumber>
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            <dateOfFirstSale>
                <value>2019-01-31</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
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        <typesOfSecuritiesOffered>
            <isDebtType>true</isDebtType>
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            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
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        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>11770500</totalOfferingAmount>
            <totalAmountSold>11770375</totalAmountSold>
            <totalRemaining>125</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>65</totalNumberAlreadyInvested>
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        <salesCommissionsFindersFees>
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                <dollarAmount>0</dollarAmount>
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            <findersFees>
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                <dollarAmount>0</dollarAmount>
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        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>CASTLE BIOSCIENCES INC</issuerName>
                <signatureName>/s/ Derek Maetzold</signatureName>
                <nameOfSigner>Derek Maetzold</nameOfSigner>
                <signatureTitle>President and CEO</signatureTitle>
                <signatureDate>2019-03-18</signatureDate>
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