<SEC-DOCUMENT>0001144204-12-013875.txt : 20120308
<SEC-HEADER>0001144204-12-013875.hdr.sgml : 20120308
<ACCEPTANCE-DATETIME>20120308211313
ACCESSION NUMBER:		0001144204-12-013875
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20120306
FILED AS OF DATE:		20120308
DATE AS OF CHANGE:		20120308

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			XOMA Corp
		CENTRAL INDEX KEY:			0000791908
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				942756657
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2910 SEVENTH ST
		CITY:			BERKELEY
		STATE:			CA
		ZIP:			94710
		BUSINESS PHONE:		5106441170

	MAIL ADDRESS:	
		STREET 1:		2910 SEVENTH ST
		CITY:			BERKLEY
		STATE:			CA
		ZIP:			94710

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	XOMA LTD /DE/
		DATE OF NAME CHANGE:	19990107

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	XOMA CORP /DE/
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

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

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14710
		FILM NUMBER:		12678793

	MAIL ADDRESS:	
		STREET 1:		BAKER BROTHERS ADVISORS
		STREET 2:		667 MADISON AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

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

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14710
		FILM NUMBER:		12678794

	MAIL ADDRESS:	
		STREET 1:		BAKER BROTHERS ADVISORS
		STREET 2:		667 MADISON AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Baker Brothers Life Sciences Capital (GP), LLC
		CENTRAL INDEX KEY:			0001307729
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14710
		FILM NUMBER:		12678795

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065
		BUSINESS PHONE:		212-339-5600

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10065

	FORMER NAME:	
		FORMER CONFORMED NAME:	Baker Biotech Capital III (GP), LLC
		DATE OF NAME CHANGE:	20041103
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>form323010_20120308091233-.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0204</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2012-03-06</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000791908</issuerCik>
        <issuerName>XOMA Corp</issuerName>
        <issuerTradingSymbol>XOMA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001307729</rptOwnerCik>
            <rptOwnerName>Baker Brothers Life Sciences Capital (GP), LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>667 MADISON AVENUE, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</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, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</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, 21ST FLOOR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>US 10065</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13606093</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through Partnership</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock Warrant (right to buy)</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.76</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6608225</value>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through Partnership</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">In addition to Baker Brothers Life Sciences Capital (GP), LLC, this Form 3 is being filed jointly by Julian C. Baker and Felix J. Baker each of whom has the same business address as Baker Brothers Life Sciences Capital (GP), LLC and may be deemed to have a pecuniary interest in securities owned by it. Because of certain relationships with other security holders of the Issuer, the Reporting Persons are filing solely for informational purposes as if they were a member of a group of such shareholders. (Continued in footnote 2).</footnote>
        <footnote id="F2">However, the Reporting Persons disclaim that they and any other person or persons, 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 securities owned by any such other persons, and each of them disclaims beneficial ownership of securities reported herein except to the extent of their pecuniary interest, if any, therein.</footnote>
        <footnote id="F3">Represents securities owned directly by Baker Brothers Life Sciences, L.P., the sole general partner of which is Baker Brothers Life Sciences Capital, L.P., a limited partnership the sole general partner of which is Baker Brothers Life Sciences Capital (GP),LLC. Julian C. Baker and Felix J. Baker are controlling members of Baker Brothers Life Sciences Capital (GP), LLC.</footnote>
        <footnote id="F4">Exercisable immediately</footnote>
        <footnote id="F5">Expiration date is 5 years from the date of Issuance</footnote>
        <footnote id="F6">Represents 13,216,449 warrant shares each of which is exercisable for .5 shares of the Issuers common stock at an exercise price of $1.76 per share.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Julian C. Baker, as Managing Member of Baker Brothers Life Sciences Capital (GP), LLC</signatureName>
        <signatureDate>2012-03-08</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Julian C. Baker</signatureName>
        <signatureDate>2012-03-08</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Felix J. Baker</signatureName>
        <signatureDate>2012-03-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
