-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HAOFc7Pqa+cBbjZ/S+oqMRxRVrYhKr9tVhGJUDyZl2wQmYnnlkHqCbqSRELpNJbA
 AtQ6kB9dkSPBU6jEARVB8w==

<SEC-DOCUMENT>0001144204-06-012012.txt : 20060328
<SEC-HEADER>0001144204-06-012012.hdr.sgml : 20060328
<ACCEPTANCE-DATETIME>20060328215329
ACCESSION NUMBER:		0001144204-06-012012
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060324
FILED AS OF DATE:		20060328
DATE AS OF CHANGE:		20060328

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IDERA PHARMACEUTICALS, INC.
		CENTRAL INDEX KEY:			0000861838
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		IRS NUMBER:				043072298
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		345 VASSAR STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139
		BUSINESS PHONE:		6176795500

	MAIL ADDRESS:	
		STREET 1:		345 VASSAR STREET
		CITY:			CAMBRIDGE
		STATE:			MA
		ZIP:			02139

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HYBRIDON INC
		DATE OF NAME CHANGE:	19951211

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:	001-31918
		FILM NUMBER:		06716529

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

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021

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:	001-31918
		FILM NUMBER:		06716530

	BUSINESS ADDRESS:	
		STREET 1:		TISCH FAMILY INTERESTS
		STREET 2:		667 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021
		BUSINESS PHONE:		212 521 2418

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Baker Biotech Capital III (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:	001-31918
		FILM NUMBER:		06716531

	BUSINESS ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		17TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021
		BUSINESS PHONE:		212 521 2418

	MAIL ADDRESS:	
		STREET 1:		667 MADISON AVENUE
		STREET 2:		17TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10021
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>v038864_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2006-03-24</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000861838</issuerCik>
        <issuerName>IDERA PHARMACEUTICALS, INC.</issuerName>
        <issuerTradingSymbol>IDP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001307729</rptOwnerCik>
            <rptOwnerName>Baker Biotech Capital III (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>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</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>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4595732</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>see footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">In addition to Baker Biotech Capital II (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 Biotech Capital II (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 with 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 Biotech Fund II, L.P., a limited partnership the sole general partner of which
 is Baker Biotech Capital II, L.P., a limited partnership the sole general partner of which is Baker Biotech Capital II (GP),
 LLC.  Felix J. Baker and Julian C. Baker are the controlling members of Baker Biotech Capital II (GP), LLC</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Julian C. Baker, as Managing Member of Baker Biotech Capital III (GP), LLC</signatureName>
        <signatureDate>2006-03-28</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Julian C. Baker</signatureName>
        <signatureDate>2006-03-28</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Felix J. Baker</signatureName>
        <signatureDate>2006-03-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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