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        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001769740</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



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        <issuerInfo>
            <issuerCik>0001597264</issuerCik>
            <issuerName>BLUEPRINT MEDICINES CORP</issuerName>
            <secFileNumber>001-37359</secFileNumber>
            <issuerAddress>
                <ns2:street1>45 Sidney Street</ns2:street1>
                <ns2:city>Cambridge</ns2:city>
                <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                <ns2:zipCode>02139</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>6173747580</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>ARIEL HURLEY</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>2250</noOfUnitsSold>
            <aggregateMarketValue>217282.50</aggregateMarketValue>
            <noOfUnitsOutstanding>63906011</noOfUnitsOutstanding>
            <approxSaleDate>03/03/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>03/01/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>2250</amountOfSecuritiesAcquired>
            <paymentDate>03/01/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for ARIEL HURLEY</name>
                <address>
                    <ns2:street1>45 Sidney Street</ns2:street1>
                    <ns2:city>Cambridge</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02139</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>01/13/2025</saleDate>
            <amountOfSecuritiesSold>2250</amountOfSecuritiesSold>
            <grossProceeds>225000.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for ARIEL HURLEY</name>
                <address>
                    <ns2:street1>45 Sidney Street</ns2:street1>
                    <ns2:city>Cambridge</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02139</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>12/12/2024</saleDate>
            <amountOfSecuritiesSold>1819</amountOfSecuritiesSold>
            <grossProceeds>169630.47</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>03/03/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>09/12/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Ariel Hurley</signature>
        </noticeSignature>
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144
0001769740
XXXXXXXX
LIVE
0001597264
BLUEPRINT MEDICINES CORP
001-37359
45 Sidney Street
Cambridge
MA
02139
6173747580
ARIEL HURLEY
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
2250
217282.50
63906011
03/03/2025
NASDAQ
Common
03/01/2024
Restricted Stock Units
Issuer
N
2250
03/01/2024
N/A
N
10b5-1 Sales for ARIEL HURLEY
45 Sidney Street
Cambridge
MA
02139
Common
01/13/2025
2250
225000.00
10b5-1 Sales for ARIEL HURLEY
45 Sidney Street
Cambridge
MA
02139
Common
12/12/2024
1819
169630.47
03/03/2025
09/12/2024
/s/ Ariel Hurley