Organization	6 Months Ended
Jun. 30, 2014
Accounting Policies [Abstract]
Organization	(1) Organization Idera Pharmaceuticals, Inc. (“Idera” or the “Company”) is a clinical stage biotechnology company advancing drug candidates for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of orphan autoimmune diseases. These drug candidates are designed to inhibit over-activation of specific Toll-like receptors (“TLRs”). In addition to Idera’s TLR program, the Company has initiated a research program to develop its gene silencing oligonucleotides (“GSOs”) to inhibit the production of disease-associated proteins by targeting RNA. The Company’s lead drug candidate in its TLR program is IMO-8400, an antagonist of TLR7, TLR8, and TLR9. A TLR antagonist is a compound that blocks activation of an immune response through the targeted TLR. IMO-8400 is in clinical development for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of selected orphan autoimmune diseases. The Company has completed a Phase 1 trial of IMO-8400 in healthy subjects and a Phase 2 randomized, placebo-controlled trial in patients with moderate to severe plaque psoriasis. In both trials, IMO-8400 has been well tolerated and, in the Phase 2 trial, has shown clinical proof of concept. Currently IMO-8400 is being evaluated in a Phase 1/2 trial in patients with Waldenström’s macroglobulinemia and in a Phase 1/2 trial in patients with diffuse large B-cell lymphoma, or DLBCL, who harbor the MYD88 L265P oncogenic mutation. The Company is also advancing, a second novel antagonist of TLR7, TLR8, and TLR9, IMO-9200, as a drug candidate for potential use in selected autoimmune disease indications. The Company has completed preclinical studies of IMO-9200 to support initiation of clinical development. Idera’s business strategy is to develop IMO-8400, IMO-9200, and other TLR antagonist drug candidates for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of orphan autoimmune diseases with unmet medical needs. In addition, the Company may seek to enter into collaborative alliances with pharmaceutical companies to advance its TLR antagonist candidates in broader autoimmune disease indications, such as psoriasis, lupus, and arthritis. At June 30, 2014, the Company had an accumulated deficit of $430,153,000. The Company expects to incur substantial operating losses in future periods. The Company does not expect to generate significant product revenue, sales-based milestones or royalties until the Company successfully completes development and obtains marketing approval for drug candidates, either alone or in collaborations with third parties, which the Company expects will take a number of years. In order to commercialize its drug candidates, the Company needs to complete clinical development and comply with comprehensive regulatory requirements. The Company is subject to a number of risks and uncertainties similar to those of other companies of the same size within the biotechnology industry, such as uncertainty of clinical trial outcomes, uncertainty of additional funding, and history of operating losses.

Organization

6 Months Ended

Jun. 30, 2014

(1) Organization

Idera Pharmaceuticals, Inc. (“Idera” or the “Company”) is a clinical stage biotechnology company advancing drug candidates for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of orphan autoimmune diseases. These drug candidates are designed to inhibit over-activation of specific Toll-like receptors (“TLRs”). In addition to Idera’s TLR program, the Company has initiated a research program to develop its gene silencing oligonucleotides (“GSOs”) to inhibit the production of disease-associated proteins by targeting RNA.

The Company’s lead drug candidate in its TLR program is IMO-8400, an antagonist of TLR7, TLR8, and TLR9. A TLR antagonist is a compound that blocks activation of an immune response through the targeted TLR. IMO-8400 is in clinical development for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of selected orphan autoimmune diseases. The Company has completed a Phase 1 trial of IMO-8400 in healthy subjects and a Phase 2 randomized, placebo-controlled trial in patients with moderate to severe plaque psoriasis. In both trials, IMO-8400 has been well tolerated and, in the Phase 2 trial, has shown clinical proof of concept. Currently IMO-8400 is being evaluated in a Phase 1/2 trial in patients with Waldenström’s macroglobulinemia and in a Phase 1/2 trial in patients with diffuse large B-cell lymphoma, or DLBCL, who harbor the MYD88 L265P oncogenic mutation. The Company is also advancing, a second novel antagonist of TLR7, TLR8, and TLR9, IMO-9200, as a drug candidate for potential use in selected autoimmune disease indications. The Company has completed preclinical studies of IMO-9200 to support initiation of clinical development.

Idera’s business strategy is to develop IMO-8400, IMO-9200, and other TLR antagonist drug candidates for the treatment of certain genetically defined forms of B-cell lymphoma and for the treatment of orphan autoimmune diseases with unmet medical needs. In addition, the Company may seek to enter into collaborative alliances with pharmaceutical companies to advance its TLR antagonist candidates in broader autoimmune disease indications, such as psoriasis, lupus, and arthritis.

At June 30, 2014, the Company had an accumulated deficit of $430,153,000. The Company expects to incur substantial operating losses in future periods. The Company does not expect to generate significant product revenue, sales-based milestones or royalties until the Company successfully completes development and obtains marketing approval for drug candidates, either alone or in collaborations with third parties, which the Company expects will take a number of years. In order to commercialize its drug candidates, the Company needs to complete clinical development and comply with comprehensive regulatory requirements.

The Company is subject to a number of risks and uncertainties similar to those of other companies of the same size within the biotechnology industry, such as uncertainty of clinical trial outcomes, uncertainty of additional funding, and history of operating losses.