Idera Pharmaceuticals Inc (NASDAQ:IDRA) is providing certain information as an update to the information provided in the Company’s previous periodic filings with the Securities and Exchange Commission in order to reflect recent business developments. Updated risk factors and a summary description of the Company’s business are filed herewith as Exhibits 99.1 and 99.2, respectively, and are incorporated herein by reference. This Current Report on Form 8-K, including the exhibits hereto, should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2015, the Company’s Quarterly Reports on Form 10-Q for the quarters ended March 31, 2016 and June 30, 2016 and the Company’s Current Reports on Form 8-K during fiscal year 2016.

On October 5, 2016, the Company issued a press release announcing its intention to offer and sell $50,000,000 of shares of its common stock in an underwritten public offering, subject to market conditions and other factors, pursuant to the Company’s effective Registration Statement on Form S-3 (File No. 333-195896). The full text of the press release issued in connection with the announcement is attached to this Current Report on Form 8-K as Exhibit 99.3 and is incorporated herein by reference.