Preclinical data of dual TLR7 and TLR8 agonist in cancer published

Idera Pharmaceuticals, Inc. (Nasdaq: IDRA) today announced the publication of data from studies of a dual agonist of Toll-like Receptor 7 (TLR7) and TLR8 in preclinical models of cancer. The Company created this first-in-class RNA-based dual agonist of TLR7 and TLR8 through its chemistry-based approach to identifying novel TLR-targeted drug candidates. The paper entitled "Antitumor Activity and Immune Response Induction of a Dual Agonist of Toll-like Receptors 7 and 8" is published in the June issue of Molecular Cancer Therapeutics (Vol. 9: 1788, 2010) and is authored by Idera scientists.

“We plan to present data from ongoing studies in preclinical models of hematological malignancies at upcoming scientific meetings. We intend to use the results of these studies to confirm selection of a dual TLR7 and TLR8 agonist as a lead drug candidate by the end of the year.”

"Our proprietary dual TLR7 and TLR8 agonist induced strong Th1-type immune responses and showed mechanism-based antitumor activity in preclinical models of cancer," said Tim Sullivan, Ph.D., Vice President of Development Programs and Alliance Management. "We plan to present data from ongoing studies in preclinical models of hematological malignancies at upcoming scientific meetings. We intend to use the results of these studies to confirm selection of a dual TLR7 and TLR8 agonist as a lead drug candidate by the end of the year."

In the published studies, one of the Company's dual TLR7 and TLR8 agonists ("agonist") was evaluated for its ability to induce immune responses and its antitumor effects in preclinical models of cancers. Administration of the agonist elicited a potent dose-dependent antitumor activity that was associated with induction of both innate and adaptive immune responses, development of tumor antigen-specific interferon-gamma secreting effector cells, and reduced frequency of T-regulatory cells at the tumor site. Absence of agonist activity in TLR7 and MyD88 (an adaptor molecule in the TLR7 signaling pathway) knockout mice confirmed that the agonist works through the TLR7 pathway.

TLR7 is expressed in human B-cells and plasmacytoid dendritic cells. TLR8 is expressed in human myeloid dendritic cells and monocytes. TLR8 is non-functional in mice.