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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 G7KUtc3Qw7vAIqdBLamZSzlAKCuS3mnmRNQ5PY/3eZjgOyCIA0bbzZxMyjDW5QzV
 VCn+h2+4HSQ8eZ6edHX68g==

<SEC-DOCUMENT>0001179110-03-007607.txt : 20030919
<SEC-HEADER>0001179110-03-007607.hdr.sgml : 20030919
<ACCEPTANCE-DATETIME>20030919124722
ACCESSION NUMBER:		0001179110-03-007607
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030918
FILED AS OF DATE:		20030919

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RYAN UNA S
		CENTRAL INDEX KEY:			0001255349

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-15006
		FILM NUMBER:		03902239

	MAIL ADDRESS:	
		STREET 1:		329 HAMMOND STREET
		CITY:			CHESTNUT HILL
		STATE:			MA
		ZIP:			02467

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AVANT IMMUNOTHERAPEUTICS INC
		CENTRAL INDEX KEY:			0000744218
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				133191702
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		119 FOURTH AVE
		CITY:			NEEDHAM
		STATE:			MA
		ZIP:			02494
		BUSINESS PHONE:		7814330771

	MAIL ADDRESS:	
		STREET 1:		119 FOURTH AVE
		CITY:			NEEDHAM
		STATE:			MA
		ZIP:			021942725

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	T CELL SCIENCES INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-09-18</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000744218</issuerCik>
        <issuerName>AVANT IMMUNOTHERAPEUTICS INC</issuerName>
        <issuerTradingSymbol>AVAN</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001255349</rptOwnerCik>
            <rptOwnerName>RYAN UNA S</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>329 HAMMOND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHESTNUT HILL</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02467</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>President &amp; CEO</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-09-18</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>400000</value>
</transactionShares>
<transactionPricePerShare><value>0</value>
<footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>456913</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">Deferred stock award consisting of 400,000 "Restricted Stock Units."  Each "Restricted Stock Unit" relates to one share of common stock.  100,000 "Units" vest annually beginning July 17, 2004 and ending July 17, 2007.</footnote>
</footnotes>
<ownerSignature><signatureName>Una S. Ryan</signatureName>
<signatureDate>2003-09-19</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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