<SEC-DOCUMENT>0001969223-25-000715.txt : 20250903
<SEC-HEADER>0001969223-25-000715.hdr.sgml : 20250903
<ACCEPTANCE-DATETIME>20250903160238
ACCESSION NUMBER:		0001969223-25-000715
CONFORMED SUBMISSION TYPE:	144
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250903
DATE AS OF CHANGE:		20250903

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IONIS PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0000874015
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				330336973
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		144
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	000-19125
		FILM NUMBER:		251289574

	BUSINESS ADDRESS:	
		STREET 1:		2855 GAZELLE COURT
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92010
		BUSINESS PHONE:		7609319200

	MAIL ADDRESS:	
		STREET 1:		2855 GAZELLE COURT
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92010

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ISIS PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	19930328

REPORTING-OWNER:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KLEIN JOSEPH III
		CENTRAL INDEX KEY:			0001206369
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		144

	MAIL ADDRESS:	
		STREET 1:		C/O IONIS PHARMACEUTICALS, INC.
		STREET 2:		2855 GAZELLE COURT
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92010
</SEC-HEADER>
<DOCUMENT>
<TYPE>144
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:com="http://www.sec.gov/edgar/common">
  <headerData>
    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001206369</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0000874015</issuerCik>
      <issuerName>IONIS PHARMACEUTICALS INC</issuerName>
      <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>KLEIN JOSEPH III</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Director</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>UBS Financial Services, Inc.</name>
        <address>
          <com:street1>11 Madison Avenue</com:street1>
          <com:street2>4th Floor</com:street2>
          <com:city>New York</com:city>
          <com:stateOrCountry>NY</com:stateOrCountry>
          <com:zipCode>10010</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>28000</noOfUnitsSold>
      <aggregateMarketValue>1680000.00</aggregateMarketValue>
      <noOfUnitsOutstanding>159391229</noOfUnitsOutstanding>
      <approxSaleDate>09/03/2024</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>COMMON</securitiesClassTitle>
      <acquiredDate>09/03/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Exercise of Stock Option</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>28000</amountOfSecuritiesAcquired>
      <paymentDate>09/03/2024</paymentDate>
      <natureOfPayment>Cash</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <remarks>9,334 shares represented in this filing are being sold under the 2011 Lucy S. Klein Trust, 9,333 shares are being sold under the 2011 Noah Z. Klein Trust and 9,333 shares are being sold under the 2011 Alexander J. Klein Trust.</remarks>
    <noticeSignature>
      <noticeDate>09/03/2025</noticeDate>
      <planAdoptionDates>
        <planAdoptionDate>01/03/2024</planAdoptionDate>
      </planAdoptionDates>
      <signature>/s/ UBS Financial Services Inc, as attorney-in-fact for Judith S Sandler</signature>
    </noticeSignature>
  </formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
