Release Details

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Sept. 17, 2007--Idera Pharmaceuticals, Inc. (AMEX: IDP), today announced preclinical data on IMO-2125, its lead Toll-Like Receptor (TLR) 9 agonist for the treatment of hepatitis C virus (HCV) infection, and other TLR9 agonists. The data were presented at the 47th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) being held in Chicago, IL, September 17-20, 2007.

Abstract 1583 entitled "IMO-2125, a TLR9 Agonist that Induces High Interferon-(alpha) Production, as a Candidate for Hepatitis C Therapy" was presented by Tim Sullivan, Ph.D., of Idera. In the study, IMO-2125 induced dose-dependent induction of interferon-(alpha) and other cytokines and chemokines in human immune cell cultures in vitro and in non-human primates in vivo. In addition, supernatants from cell cultures and plasma from non-human primates treated with IMO-2125 demonstrated potent antiviral activity in the HCV replicon assay, an in vitro system to measure the potency of antiviral compounds against HCV replication.

Abstract 2714 entitled "Impact of Secondary Structure of Agonists of TLR9 on Interferon-(alpha) Induction" was presented by Ekambar Kandimalla, Ph.D., of Idera. In the study, Idera compared one of its proprietary TLR9 agonists with two TLR9 agonists published by others to assess their abilities to induce immune responses in human immune cells in vitro and in non-human primates in vivo. One of these TLR9 agonists forms intra-molecular secondary structures and two form inter-molecular secondary structures. The major observation from this study is that the TLR9 agonist that has the ability to form intra-molecular secondary structures had reduced ability to induce immune responses in vivo but not in vitro. The Company has taken these findings into consideration in designing IMO-2125.

"These results support our ongoing Phase 1 study investigating IMO-2125 in patients with HCV infection," said Sudhir Agrawal, D. Phil., Chief Executive Officer and Chief Scientific Officer. "IMO-2125 was generated by Idera's chemistry-based drug discovery approach and specifically designed to induce high levels of interferon-(alpha) in preclinical models for the potential treatment of HCV."

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 specific TLRs, which are a family of immune system receptors. 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's second TLR9 agonist, IMO-2125, is currently in a Phase 1 trial for the treatment of hepatitis C virus infection. 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 results obtained in early clinical studies or in preclinical studies such as the studies referred to above will be indicative of results obtained in future clinical trials or warrant additional trials; 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, if the Company's products receive approval, they will be successfully distributed and marketed; whether the Company's collaborations with Novartis and Merck will be successful; 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 August 1, 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.