Idera Pharmaceuticals, Inc. (NASDAQ: IDRA) today presented new data on its novel gene-silencing oligonucleotide (GSO) technology at the 12 th annual EuroTIDES conference being held in Berlin, Germany November 15-16, 2011. The preclinical data demonstrated that GSOs exert target-specific gene-silencing activity following systemic delivery and, due to their novel structure, minimize the sequence-dependent immune stimulation that is associated with other approaches to gene-silencing. “We are very pleased to have observed that the novel structure of GSOs, in which the five-prime end is not accessible, minimizes immune stimulation,” commented Nicola La Monica, Ph.D., Vice President of Biology at Idera Pharmaceuticals. “The immune stimulatory effects of other gene-silencing approaches have resulted in off-target effects that may interfere with the intended mechanism of action or have other unintended consequences. GSOs provide a potential approach for gene-silencing following systemic delivery with reduced off-target effects.” The data presented are from preclinical studies evaluating the gene silencing activity of GSOs targeted to various messenger RNA targets. The GSOs were administered systemically to mice, without the use of any delivery technology. The GSOs showed significant specific gene-silencing activity as monitored by suppression of targeted RNA and protein. For comparison, a number of antisense sequences were evaluated for in vivo immune activation, as monitored by circulating cytokines. The data showed that GSOs minimized the induction of immune responses compared to antisense oligonucleotides. GSOs are single-stranded oligonucleotides with two exposed 3’-ends and 5’-ends that are not accessible. It has been shown that accessibility of the 5’-ends of oligonucleotides maximizes immune activation. The presentation entitled “ Gene-silencing oligonucleotides: Innovative design of oligonucleotides with enhanced efficacy and RNAi-like mechanism of action” was presented by Nicola La Monica of Idera Pharmaceuticals. About Gene-silencing Oligonucleotides Idera's gene-silencing oligonucleotides (GSOs) are single-stranded RNA or DNA constructs with two exposed 3'-ends that are complementary to targeted mRNA sequences of therapeutic interest. In preclinical studies, GSOs have inhibited gene expression in vivo without requiring a delivery enhancement technology. Idera has filed multiple patent applications for its GSOs that are pending in many countries around the world.