FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   Baker Biotech Capital III (Z) (GP), LLC 2. Date of Event Requiring Statement (Month/Day/Year) 03/24/2006 3. Issuer Name and Ticker or Trading Symbol IDERA PHARMACEUTICALS, INC. [IDP] (Last) (First) (Middle) 667 MADISON AVENUE 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) NEW YORK, NY 10021 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock (1) 811,124 (3) I see footnote (2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Baker Biotech Capital III (Z) (GP), LLC 667 MADISON AVENUE NEW YORK, NY 10021	Â	  X	Â	Â
BAKER JULIAN 667 MADISON AVENUE NEW YORK, NY 10021	Â	  X	Â	Â
BAKER FELIX 667 MADISON AVENUE NEW YORK, NY 10021	Â	  X	Â	Â

Signatures

Julian C. Baker, as Managing Member of Baker Biotech Capital III (Z) (GP), LLC		03/28/2006
**Signature of Reporting Person		Date
Julian C. Baker		03/28/2006
**Signature of Reporting Person		Date
Felix J. Baker		03/28/2006
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	In addition to Baker Biotech Capital III (Z) (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 III (Z) (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.)
(2)	However, the Reporting Persons disclaim that they and any other person or persons, in fact constitute a "group" 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.
(3)	Represents securities owned directly by Baker Biotech Fund III (Z), L.P., a limited partnership of which the sole general partner is Baker Biotech Capital III (Z), L.P., a limited partnership of which the sole general partner is Baker Biotech Capital III (Z) (GP), LLC. Felix J. Baker and Julian C. Baker are the controlling members of Baker Biotech Capital III (Z) (GP), LLC.

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