Idera Pharmaceuticals, Inc. is a clinical-stage biotechnology company engaged in the discovery and development of novel synthetic deoxyribonucleic acid (DNA) - and ribonucleic acid (RNA) - based drug candidates. The Company is developing drug candidates that are designed to modulate immune responses mediated through Toll-like Receptors (TLRs). It is also evaluating gene silencing oligonucleotides (GSOs), which inhibit the production of disease-associated proteins by targeting RNA. During the year ended December 31, 2011, the Company collaborated with Merck Sharp & Dohme Corp., for the use of agonists of TLRs 7, 8, and 9 as vaccine adjuvants for cancer, infectious diseases, and Alzheimer’s disease. In November 2011, the Company reacquired rights to IMO-2055 from Merck KGaA, Darmstadt, Germany, its former collaborator.