<SEC-DOCUMENT>0001104659-18-017201.txt : 20180313
<SEC-HEADER>0001104659-18-017201.hdr.sgml : 20180313
<ACCEPTANCE-DATETIME>20180313181540
ACCESSION NUMBER:		0001104659-18-017201
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180312
FILED AS OF DATE:		20180313
DATE AS OF CHANGE:		20180313

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Sabba Stephen L
		CENTRAL INDEX KEY:			0001442372

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33093
		FILM NUMBER:		18687814

	MAIL ADDRESS:	
		STREET 1:		DORSET MANAGEMENT CORP
		STREET 2:		485 UNDERHILL BLVD SUITE 205
		CITY:			SYOSSET
		STATE:			NY
		ZIP:			11791

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIGAND PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0000886163
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				770160744
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		STREET 2:		SUITE 110
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		858-550-7500

	MAIL ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		STREET 2:		SUITE 110
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-03-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000886163</issuerCik>
        <issuerName>LIGAND PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>LGND</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001442372</rptOwnerCik>
            <rptOwnerName>Sabba Stephen L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>DORSET MANAGEMENT CORP</rptOwnerStreet1>
            <rptOwnerStreet2>485 UNDERHILL BLVD SUITE 205</rptOwnerStreet2>
            <rptOwnerCity>SYOSSET</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11791</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2018-03-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>622</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>180.73</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>26363</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities, as represented in Column 5, include a grant of 666 restricted shares approved by the Board of Directors of the Company at the 2017 Meeting, which shares will vest in full on the earlier of (a) the date of the next annual meeting of the Company stockholders following the grant date or (b) on the first anniversary of the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Stephen L. Sabba</signatureName>
        <signatureDate>2018-03-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
