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            <ccc>XXXXXXXX</ccc>
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        <liveTestFlag>LIVE</liveTestFlag>
  
  
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        <secFileNumber>000-19125</secFileNumber>
        <issuerAddress>
          <com:street1>2855 GAZELLE COURT</com:street1>
          <com:city>CARLSBAD</com:city>
          <com:stateOrCountry>CA</com:stateOrCountry>
          <com:zipCode>92010</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>7609319200</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Jenne Kyle</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
        <relationshipsToIssuer>
          <relationshipToIssuer>Officer</relationshipToIssuer>
        </relationshipsToIssuer>
      </issuerInfo>
      <securitiesInformation>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <brokerOrMarketmakerDetails>
          <name>Morgan Stanley Smith Barney</name>
          <address>
            <com:street1>1585 Broadway</com:street1>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10036</com:zipCode>
          </address>
        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>3016</noOfUnitsSold>
        <aggregateMarketValue>85533.81</aggregateMarketValue>
        <noOfUnitsOutstanding>157897287</noOfUnitsOutstanding>
        <approxSaleDate>04/16/2025</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
      </securitiesInformation>
      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>04/15/2025</acquiredDate>
        <natureOfAcquisitionTransaction>RSUs granted under 2020 Equity Incentive Plan</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Ionis Pharmaceuticals</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
        <amountOfSecuritiesAcquired>3016</amountOfSecuritiesAcquired>
        <paymentDate>04/15/2025</paymentDate>
        <natureOfPayment>Compensation</natureOfPayment>
      </securitiesToBeSold>
      <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>04/16/2025</noticeDate>
        <signature>Kyle Jenne</signature>
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text: 144
  0001791857
  XXXXXXXX
  LIVE
  0000874015
  IONIS PHARMACEUTICALS INC
  000-19125
  2855 GAZELLE COURT
  CARLSBAD
  CA
  92010
  7609319200
  Jenne Kyle
  Officer
  Common Stock
  Morgan Stanley Smith Barney
  1585 Broadway
  New York
  NY
  10036
  3016
  85533.81
  157897287
  04/16/2025
  NASDAQ
  Common Stock
  04/15/2025
  RSUs granted under 2020 Equity Incentive Plan
  Ionis Pharmaceuticals
  N
  3016
  04/15/2025
  Compensation
  Y
  04/16/2025
  Kyle Jenne