<SEC-DOCUMENT>0001280776-17-000017.txt : 20170327
<SEC-HEADER>0001280776-17-000017.hdr.sgml : 20170327
<ACCEPTANCE-DATETIME>20170327180255
ACCESSION NUMBER:		0001280776-17-000017
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170327
FILED AS OF DATE:		20170327
DATE AS OF CHANGE:		20170327

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			VITAL THERAPIES INC
		CENTRAL INDEX KEY:			0001280776
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		15010 AVENUE OF SCIENCE
		STREET 2:		STE. 200
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92128
		BUSINESS PHONE:		858-673-6840

	MAIL ADDRESS:	
		STREET 1:		15010 AVENUE OF SCIENCE
		STREET 2:		STE. 200
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92128

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Satter Muneer A
		CENTRAL INDEX KEY:			0001315797

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36201
		FILM NUMBER:		17716355

	MAIL ADDRESS:	
		STREET 1:		C/O SATTER INVESTMENT MANAGEMENT, LLC
		STREET 2:		676 NORTH MICHIGAN AVENUE, SUITE 4000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60611
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_149065216093806.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-03-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001280776</issuerCik>
        <issuerName>VITAL THERAPIES INC</issuerName>
        <issuerTradingSymbol>VTL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001315797</rptOwnerCik>
            <rptOwnerName>Satter Muneer A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VITAL THERAPIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>15010 AVENUE OF SCIENCE, SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92128</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-03-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3750000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10882277</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">All shares were purchased by Satter Medical Technology Partners, L.P. in connection with the Issuer's registered public offering of common stock.</footnote>
        <footnote id="F2">The amount in Column 5 includes (a) 4,202,930 shares that are held by the Muneer A. Satter Revocable Trust for which the Reporting Person serves as trustee and, in such capacity, has sole voting and dispositive power over all such shares, (b) 2,929,347 shares that are held by various other trusts and other entities for which the Reporting Person serves as trustee, investment advisor or manager and, in such capacity, has sole voting and dispositive power over all such shares, and (c) 3,750,000 shares that are held by Satter Medical Technology Partners, L.P. for which the Reporting Person has sole voting and dispositive power over all such shares. The Reporting Person disclaims beneficial ownership of all shares included in clauses (b) and (c) of this footnote (2), except to the extent of his pecuniary interest.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jon-Micheal A. Wheat, by power of attorney</signatureName>
        <signatureDate>2017-03-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
