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            <secFileNumber>001-41259</secFileNumber>
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                <ns2:city>GAITHERSBURG</ns2:city>
                <ns2:stateOrCountry>MD</ns2:stateOrCountry>
                <ns2:zipCode>20878</ns2:zipCode>
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            <issuerContactPhone>2403270603</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Christopher Ryan Heery</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
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            <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>38th Fl.</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
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            <aggregateMarketValue>377190.00</aggregateMarketValue>
            <noOfUnitsOutstanding>47840388</noOfUnitsOutstanding>
            <approxSaleDate>05/03/2023</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
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            <acquiredDate>05/03/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
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            <paymentDate>05/03/2023</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
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        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
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                    <ns2:city>GAITHERSBURG</ns2:city>
                    <ns2:stateOrCountry>MD</ns2:stateOrCountry>
                    <ns2:zipCode>20878</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>04/24/2023</saleDate>
            <amountOfSecuritiesSold>20000</amountOfSecuritiesSold>
            <grossProceeds>800067.25</grossProceeds>
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                    <ns2:stateOrCountry>MD</ns2:stateOrCountry>
                    <ns2:zipCode>20878</ns2:zipCode>
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            <securitiesClassTitle>Common</securitiesClassTitle>
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            <grossProceeds>547660.15</grossProceeds>
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                    <ns2:stateOrCountry>MD</ns2:stateOrCountry>
                    <ns2:zipCode>20878</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>04/18/2023</saleDate>
            <amountOfSecuritiesSold>6000</amountOfSecuritiesSold>
            <grossProceeds>210000.00</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
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                    <ns2:stateOrCountry>MD</ns2:stateOrCountry>
                    <ns2:zipCode>20878</ns2:zipCode>
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            <amountOfSecuritiesSold>3000</amountOfSecuritiesSold>
            <grossProceeds>92120.70</grossProceeds>
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        <noticeSignature>
            <noticeDate>05/03/2023</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>06/30/2022</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ CHRISTOPHER HEERY</signature>
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144
0001789632
XXXXXXXX
LIVE
0001786205
ARCELLX INC
001-41259
25 WEST WATKINS MILL ROAD, SUITE A
GAITHERSBURG
MD
20878
2403270603
Christopher Ryan Heery
Officer
COMMON
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
38th Fl.
New York
NY
10004
9000
377190.00
47840388
05/03/2023
NASDAQ
Common
05/03/2023
Exercise of Stock Options
Issuer
N
9000
05/03/2023
Cash
N
10b5-1 Sales Plan for CHRISTOPHER R HEERY
25 WEST WATKINS MILL ROAD, SUITE A
GAITHERSBURG
MD
20878
Common
04/24/2023
20000
800067.25
10b5-1 Sales Plan for CHRISTOPHER R HEERY
25 WEST WATKINS MILL ROAD, SUITE A
GAITHERSBURG
MD
20878
Common
04/19/2023
15642
547660.15
10b5-1 Sales Plan for CHRISTOPHER R HEERY
25 WEST WATKINS MILL ROAD, SUITE A
GAITHERSBURG
MD
20878
Common
04/18/2023
6000
210000.00
10b5-1 Sales Plan for CHRISTOPHER R HEERY
25 WEST WATKINS MILL ROAD, SUITE A
GAITHERSBURG
MD
20878
Common
04/03/2023
3000
92120.70
05/03/2023
06/30/2022
/s/ CHRISTOPHER HEERY