<SEC-DOCUMENT>0000874015-25-000215.txt : 20250904
<SEC-HEADER>0000874015-25-000215.hdr.sgml : 20250904
<ACCEPTANCE-DATETIME>20250904203411
ACCESSION NUMBER:		0000874015-25-000215
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250903
FILED AS OF DATE:		20250904
DATE AS OF CHANGE:		20250904

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Baroldi Joseph
		CENTRAL INDEX KEY:			0001813775
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19125
		FILM NUMBER:		251294793

	MAIL ADDRESS:	
		STREET 1:		C/O IONIS PHARMACEUTICALS, INC.
		STREET 2:		C/O IONIS PHARMACEUTICALS, INC.
		CITY:			CARLSBAD
		STATE:			CA
		ZIP:			92010

ISSUER:		

	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

	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
</SEC-HEADER>
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    <issuer>
        <issuerCik>0000874015</issuerCik>
        <issuerName>IONIS PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>IONS</issuerTradingSymbol>
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    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001813775</rptOwnerCik>
            <rptOwnerName>Baroldi Joseph</rptOwnerName>
        </reportingOwnerId>
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            <rptOwnerStreet1>2855 GAZELLE COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CARLSBAD</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Chief Business Officer</officerTitle>
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    </reportingOwner>

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                <transactionPricePerShare>
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                </transactionAcquiredDisposedCode>
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            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
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            <transactionDate>
                <value>2025-09-03</value>
            </transactionDate>
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            <transactionAmounts>
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                    <value>2800</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2023-01-31</value>
            </exerciseDate>
            <expirationDate>
                <value>2032-01-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
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                </underlyingSecurityShares>
            </underlyingSecurity>
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                </sharesOwnedFollowingTransaction>
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                </directOrIndirectOwnership>
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        <derivativeTransaction>
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            </transactionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <value>2023-01-31</value>
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            </expirationDate>
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                <underlyingSecurityTitle>
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                </underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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                <transactionCode>M</transactionCode>
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                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <value>2023-01-31</value>
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            <expirationDate>
                <value>2032-01-30</value>
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                <underlyingSecurityTitle>
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                </underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
                    <value>53900</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 2, 2025.</footnote>
        <footnote id="F2">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $58.59 to $59.26 inclusive.  The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc. any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) on this Form 4.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $62.00 to $62.03 inclusive.  The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc. any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (3) on this Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Patrick R. O'Neil, attorney-in-fact For: Joseph T. Baroldi</signatureName>
        <signatureDate>2025-09-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</SEC-DOCUMENT>
