-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001181431-04-039503.txt : 20040809
<SEC-HEADER>0001181431-04-039503.hdr.sgml : 20040809
<ACCEPTANCE-DATETIME>20040809181908
ACCESSION NUMBER:		0001181431-04-039503
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040806
FILED AS OF DATE:		20040809

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER BROS CAPITAL GP LLC
		CENTRAL INDEX KEY:			0001244390
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-50266
		FILM NUMBER:		04962612

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVE 17TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER JULIAN
		CENTRAL INDEX KEY:			0001087939

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-50266
		FILM NUMBER:		04962611

	BUSINESS ADDRESS:	
		STREET 1:		TISCH FAMILY INTERESTS
		STREET 2:		667 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021
		BUSINESS PHONE:		2125212420

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAKER FELIX
		CENTRAL INDEX KEY:			0001087940

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-50266
		FILM NUMBER:		04962610

	BUSINESS ADDRESS:	
		STREET 1:		TISCH FAMILY INTERESTS
		STREET 2:		667 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021
		BUSINESS PHONE:		2125212420

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SEATTLE GENETICS INC /WA
		CENTRAL INDEX KEY:			0001060736
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				911874389
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		21823 30TH DRIVE SE
		STREET 2:		SUITE
		CITY:			BOTHELL
		STATE:			WA
		ZIP:			98021
		BUSINESS PHONE:		4255274000

	MAIL ADDRESS:	
		STREET 1:		21823 30TH DRIVE SE
		STREET 2:		SUITE
		CITY:			BOTHELL
		STATE:			WA
		ZIP:			98021
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd50161.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-08-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001060736</issuerCik>
        <issuerName>SEATTLE GENETICS INC /WA</issuerName>
        <issuerTradingSymbol>SGEN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001244390</rptOwnerCik>
            <rptOwnerName>BAKER BROS CAPITAL GP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001087939</rptOwnerCik>
            <rptOwnerName>BAKER JULIAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001087940</rptOwnerCik>
            <rptOwnerName>BAKER FELIX</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10021</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3364</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.5412</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11120</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>849</value>
                    <footnoteId id="F5"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.50</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11969</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">In addition to Baker Bros. Capital (GP), LLC, this Form 4 is being filed jointly by Julian C. Baker and Felix J. Baker, each of whom has the same business address as Baker Bros. Capital (GP), LLC and may be deemed to have a pecuniary interest in securities owned by it. Because of certain business relationships with other shareholders of the Issuer, the Reporting Persons have filed on Schedule 13D as if they were a member of a group with such shareholders. However, the Reporting Persons disclaim that they and any other person or persons, including those persons with whom the Reporting Persons have filed a Schedule 13D, in fact constitute a &quot;group&quot; for purposes of Section 13(d)(3) of the Securities Exchange Act of 1934, as amended, or Rule 13d-5 thereunder, or that they are the beneficial owners of any securities owned by any other person. Felix J. Baker is a director of the Issuer.</footnote>
        <footnote id="F2">Represents 1,745 shares of common stock purchased by Baker Bros. Investments, L.P., and 1,619 shares of common stock purchased by Baker Bros. Investments II, L.P.</footnote>
        <footnote id="F3">Represents 5,793 shares of common stock owned directly by Baker Bros. Investments, L.P., and 5,327 shares of common stock owned directly by Baker Bros. Investments II, L.P.</footnote>
        <footnote id="F4">Represents shares of common stock owned directly by Baker Bros. Investments, L.P., and shares of common stock owned directly by Baker Bros. Investments II, L.P.  Baker Bros.  Investments, L.P.,  and Baker Bros. 	Investments II, L.P., are each limited partnerships of which the sole general partner is Baker Bros. Capital, L.P., a limited partnership of which the sole general partner is Baker Bros. Capital (GP), LLC.  Felix J. Baker and 	Julian C. Baker are the controlling members of Baker Bros. Capital (GP), LLC.</footnote>
        <footnote id="F5">Represents 441 shares of common stock purchased by Baker Bros. Investments, L.P., and 408 shares of common stock purchased by Baker Bros. Investments II, L.P.</footnote>
        <footnote id="F6">Represents 6,234 shares of common stock owned directly by Baker Bros. Investments, L.P., and 5,735 shares of common stock owned directly by Baker Bros. Investments II, L.P.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/S/ Julian C. Baker, as Managing Member   of Baker Bros. Capital (GP), LLC</signatureName>
        <signatureDate>2004-08-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Julian C. Baker</signatureName>
        <signatureDate>2004-08-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Felix J. Baker</signatureName>
        <signatureDate>2004-08-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

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