Idera Pharmaceuticals, Inc. (NASDAQ: IDRA) (“Idera” or, the “Company”) today announced the pricing of an underwritten public offering of 13,727,251 shares of common stock for a public offering price of $1.55 per share, and pre-funded warrants to purchase up to an aggregate of 4,175,975 shares of common stock at the per share public offering price for the common stock less the $0.01 per share exercise price for each such pre-funded warrant. The gross proceeds to Idera from this offering are expected to be approximately $27.7 million, before deducting the underwriting discounts and commissions and other estimated offering expenses payable by Idera and excluding the proceeds, if any, from the exercise of the pre-funded warrants. The offering is expected to close on or about September 30, 2013, subject to customary closing conditions. Idera anticipates using the net proceeds from the offering to fund its planned Phase 1/2 clinical trials of IMO-8400 intended to evaluate its use in certain genetically defined forms of B-cell lymphomas, to fund its planned Phase 1 clinical trial of IMO-9200 and for working capital and other general corporate purposes. Piper Jaffray & Co. is acting as sole manager for the offering. The securities described above are being offered by the Company pursuant to a shelf registration statement previously filed with and declared effective by the Securities and Exchange Commission (the “SEC”) on September 18, 2013. The offering will be made only by means of the written prospectus and prospectus supplement that form a part of the registration statement. A preliminary prospectus supplement and the accompanying prospectus relating to the securities being offered has been filed with the SEC and is available on the SEC's website at http://www.sec.gov. Copies of the preliminary prospectus supplement and the accompanying prospectus relating to the securities being offered may also be obtained from Piper Jaffray & Co., Attention: Prospectus Department, 800 Nicollet Mall, J12S03, Minneapolis, MN 55402, via telephone at 800-747-3924 or email at email@example.com. This press release shall not constitute an offer to sell or the solicitation of an offer to buy the securities being offered, nor shall there be any sale of the securities being offered in any state or other jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or other jurisdiction.