Idera Pharmaceuticals, Inc. has received clearance under the Hart-Scott-Rodino Antitrust Improvements Act for its worldwide licensing and collaboration agreement with Merck KGaA of Darmstadt, Germany, announced in December 2007. With the grant of HSR clearance, the agreement is now in effect and Idera is entitled to receive an upfront licensing fee of $40 million from Merck KGaA.

Under the agreement, Idera exclusively licensed the therapeutic oncology applications, excluding cancer vaccines, of its lead TLR9 agonists, IMO-2055 and IMO-2125. In addition, using Idera's chemistry-based approach to the design and creation of TLR-targeted compounds, Idera and Merck KGaA have agreed to engage in research to identify a specified number of novel, follow-on TLR9 agonists for which Merck KGaA will have the exclusive right to use in oncology applications other than cancer vaccines.

IMO-2055 is a novel DNA-based agonist of TLR9. IMO-2055 has been evaluated at multiple-dose levels for safety and immunological activity in phase I trials involving healthy volunteers and patients with refractory solid tumours. IMO-2055 is currently in a phase Ib trial in combination with Tarceva and Avastin in patients with advanced non-small cell lung cancer and is being evaluated at two dose levels in a phase IIa trial in patients with renal cell carcinoma. IMO-2055 also is being evaluated in combination with chemotherapy agents in a Phase 1 trial in patients with refractory solid tumours.

IMO-2125 is a second DNA-based TLR9 agonist and is of a class designed to induce high levels of interferon-alpha and other cytokines and chemokines. IMO-2125 presently is being evaluated in a phase I trial in patients with chronic hepatitis C virus infection who have not responded to standard treatment. This indication is not included in the agreement with Merck KGaA.

Toll-like Receptors (TLRs) function in human immune cells as the sensors of pathogens. They recognize different microbial products present in pathogens such as bacteria, viruses and parasites, and mount an appropriate immune response against the foreign invaders. TLRs have also been shown to recognize endogenous ligands in autoimmune diseases. TLRs have become attractive targets for developing immune modulators to treat a number of diseases including infectious diseases, autoimmune diseases, cancer, and respiratory diseases and for use as vaccine adjuvants.