Release Details

CAMBRIDGE, Mass.--(BUSINESS WIRE)--July 17, 2007--Idera Pharmaceuticals, Inc. (AMEX: IDP) today announced the presentation of preclinical data using its proprietary antagonists of Toll-like receptors (TLR) 7 and 9 in mouse models of collagen-induced arthritis (CIA), a commonly used model for rheumatoid arthritis (RA). RA is an autoimmune disease characterized primarily by Th1-like immune responses. The presentation entitled "A Novel Class of DNA-Based TLR Antagonists Ameliorates Collagen-Induced Arthritis in Mice" (Poster #52) was made during the FASEB Summer Research Conference on Autoimmunity being held in Saxtons River, VT, July 14-19, 2007.

In the study, TLR antagonist candidates, which block Th1-type cytokine induction mediated through TLRs 7 and 9, were evaluated for their ability to prevent the development of CIA in DBA/1 mice. Data from evaluation of antagonist-treated mice showed dose-dependent suppression of parameters of arthritis development, including arthritic swelling, compared with untreated mice. In addition, microscopic examination showed reduced inflammation in foot joints of the antagonist-treated mice. These findings suggest that antagonists of TLRs 7 and 9 may have a potential role in blocking Th1-type immune responses, thereby inhibiting the progression of diseases such as rheumatoid arthritis.

"Idera's chemistry-based drug discovery platform has generated a number of novel TLR antagonist candidates," said Sudhir Agrawal, D. Phil., Chief Executive Officer and Chief Scientific Officer. "Based on encouraging results of our antagonist candidates in both CIA models and previously reported lupus models, we plan to evaluate them in additional preclinical models of autoimmune diseases. By inhibiting activation of immune responses through specific TLRs, antagonists may have potential as a future treatment option in autoimmune diseases."

About Idera Pharmaceuticals, Inc.

Idera Pharmaceuticals is a drug discovery and development company that is developing drug candidates to treat cancer and infectious, respiratory, and autoimmune diseases, and for use as vaccine adjuvants. Idera's proprietary drug candidates are designed to modulate TLRs, the body's first line of immune defense. Idera's pioneering DNA chemistry expertise enables it to identify drug candidates for internal development and creates opportunities for multiple collaborative alliances. Idera's most advanced clinical candidate, IMO-2055, is an agonist of TLR9 and is currently in a Phase 2 trial in oncology and in a Phase 1/2 chemotherapy combination trial in oncology. Idera has selected a second TLR9 agonist, IMO-2125, as a lead candidate for treating infectious diseases. Idera is collaborating with Novartis International Pharmaceutical, Ltd. for the discovery, development, and commercialization of TLR9 agonists for the treatment of asthma and allergy indications. Idera is also collaborating with Merck & Co., Inc. for the use of Idera's TLR7, 8 and 9 agonists in combination with Merck's therapeutic and prophylactic vaccines in the areas of oncology, infectious diseases, and Alzheimer's disease. For more information, visit www.iderapharma.com.

Forward Looking Statements

This press release contains forward-looking statements concerning Idera Pharmaceuticals, Inc. that involve a number of risks and uncertainties. For this purpose, any statements contained herein that are not statements of historical fact may be deemed to be forward-looking statements. Without limiting the foregoing, the words "believes," "anticipates," "plans," "expects," "estimates," "intends," "should," "could," "will," "may," and similar expressions are intended to identify forward-looking statements. There are a number of important factors that could cause Idera's actual results to differ materially from those indicated by such forward-looking statements, including whether products based on Idera's technology will advance into or through the clinical trial process on a timely basis or at all and receive approval from the United States Food and Drug Administration or equivalent foreign regulatory agencies; whether the Company will complete enrollment of clinical trials or announce trial results in the time expected; whether, if the Company's products receive approval, they will be successfully distributed and marketed; whether the results of preclinical studies will be indicative of results that may be obtained in clinical trials; whether the Company's collaborations with Novartis and Merck will be successful; whether the patents and patent applications owned or licensed by Idera will protect the Company's technology and prevent others from infringing it; whether Idera's cash resources will be sufficient to fund product development and clinical trials; and such other important factors as are set forth under the caption "Risk Factors" in Idera's Quarterly Report on Form 10-Q filed on May 14, 2007, which important factors are incorporated herein by reference. Idera disclaims any intention or obligation to update any forward-looking statements.

    CONTACT: Idera Pharmaceuticals, Inc.
             Kelly Luethje, 617-679-5519
             kluethje@iderapharma.com
             or
             MacDougall Biomedical Communications
             Chris Erdman, 508-647-0209
             cerdman@macbiocom.com

    SOURCE: Idera Pharmaceuticals, Inc.