Idera Pharmaceuticals Reports Translational Data Supporting the Mechanism of Action of Intratumoral IMO-2125 from Ongoing Phase 1 Dose Escalation in Clinical Trial in Combination with Ipilimumab in Metastatic Melanoma Patients Refractory to Anti-PD-1 Treat

CAMBRIDGE, Mass. and EXTON, Pa., Nov. 11, 2016 (GLOBE NEWSWIRE) -- Idera Pharmaceuticals, Inc. (NASDAQ:IDRA), a clinical-stage biopharmaceutical company developing toll-like receptor and RNA therapeutics for patients with cancer and rare diseases, is reporting translational data supporting the mechanism of action of intratumoral IMO-2125, a Toll-like receptor (TLR) 9 agonist from the ongoing Phase 1 dose escalating clinical trial. In this trial, IMO-2125 is being evaluated in combination with ipilimumab for treatment of patients with metastatic melanoma with disease that is refractory to anti-PD-1 inhibitors, and have minimal options and low expectation of clinical response with ipilimumab treatment alone. Taken together, the previously reported early clinical responses and the supporting mechanism of action translational data being presented today, indicate that intratumoral IMO-2125 is a potent agent for the stimulation of the tumor microenvironment.

In the oral presentation at the 2016 Society for Immunotherapy of Cancer Annual Meeting (SITC), entitled “Reactivating the anti-tumor immune response by targeting innate and adaptive immunity in a phase I/II study of intratumoral IMO-2125 in combination with systemic ipilimumab in patients with anti-PD-1 refractory metastatic melanoma,” Cara Haymaker, Ph.D., from the University of Texas, MD Anderson Cancer Center, presented an overview of the modulation of the tumor microenvironment through the unique mechanism of action of intratumoral IMO-2125 and provided an update on the initial findings of the translational data through the first cohorts of the trial. Immunological analysis of the biopsy taken from the lesion injected with IMO-2125 showed rapid dendritic cell maturation which is a critical first step in the induction of the immune cascade within the tumor microenvironment. During the treatment period, T-cell expansion and activation and importantly, immune infiltration was observed in the biopsied distant lesions of the responding patients, demonstrating the abscopal effect.

From a clinical perspective, through all dosing cohorts tested to date, no dose-limiting toxicity has been seen. Preliminary clinical activity is also encouraging in this population with disease that is refractory to PD-1 inhibitors as 3 responses (including one CR) have already been recorded. The trial continues to dose escalate and enrollment into the planned anti-PD-1 inhibitor combination arm has also commenced.

“We hypothesized that the intratumoral injection of IMO-2125 into a single tumor lesion would stimulate dendritic cells to produce interferon and the downstream immune cascade in the tumor microenvironment, resulting in the recruitment and activation of tumor-killing T-cells in both the injected and non-injected tumors,” said Joanna Horobin, M.B., Ch.B., Idera’s Chief Medical Officer. “When combined with a systemic checkpoint inhibitor, this change in the tumor microenvironment was expected to affect tumor responses in both injected and distant tumors. Today Dr. Haymaker presented analyses of serial biopsies from the tumors of patients with anti-PD-1 refractory melanoma in our ongoing phase 1 dose escalation trial of intratumoral IMO-2125 which clearly demonstrated these beneficial changes in the tumor microenvironment, essentially turning “cold” tumors “hot” in responding patients. We are thrilled to see what we believe to be, the clear translation of our hypothesis in patients. Moreover, in three patients the investigator has reported substantial tumor shrinkage with 2 partial and one complete response.”

A copy of the slides from today’s presentation as well as a copy of a related poster presentation are currently available on Idera’s corporate website at

These early results are from the phase 1 portion of study IMO-2125-204 (NCT02644967) in which cohorts of patients with metastatic melanoma unresponsive to PD-1 inhibitor therapy are being administered escalating doses of IMO-2125 ranging from 4 mg/kg through 32 mg/kg. IMO-2125 is injected intra-tumorally into a designated tumor lesion together with a standard dosing regimen of ipilimumab. The trial has recently been amended to also study the combination of IMO-2125 and pembrolizumab given intravenously. Following determination of the recommended phase 2 doses (RP2D) additional patients will be treated in an expansion phase 2 portion of the study. The primary objective of the phase 1 portion of the trial is to characterize the safety and determine a RP2D of IMO-2125 when administered intra-tumorally in combination with ipilimumab or pembrolizumab. The primary objective of the phase 2 portion is to assess the clinical activity of IMO-2125 in each combination at the respective RP2Ds. Assessment will be based on the immune-related response criteria (irRC) and additionally the traditional RECIST criteria. Serial biopsies are being taken of selected injected and non-injected tumor lesions to assess immune changes and correlate with clinical response assessments. The trial will enroll approximately 60 patients. The study is being conducted at MD Anderson and is being led by Adi Diab, MD, Assistant Professor, Department of Melanoma Medical Oncology, Division of Cancer Medicine, MD Anderson as part of a strategic research alliance announced by Idera and MD Anderson in 2015.

Additionally at SITC, on November 9th, Idera’s Oncology Lead, Mark Cornfeld, M.D., M.P.H., presented an overview of IMO-2125’s unique mechanism of action in an oral presentation, entitled “IMO-2125, An Investigational Intratumoral Toll-Like Receptor 9 Agonist, Modulates the Tumor Microenvironment to Enhance Anti-Tumor Immunity” during a session focused on New Clinical Agents in Development. A copy of the slides from this presentation is currently available on Idera’s corporate website at

About Toll-like Receptors and Idera's Immuno-Oncology Research Program

Toll-like receptors (TLRs) play a central role in the innate immune system, the body's first line of defense against invading pathogens, as well as damaged or dysfunctional cells including cancer cells. The innate immune system is also involved in activating the adaptive immune system, which marshals highly specific immune responses to target pathogens or tissue. Cancer cells may exploit regulatory checkpoint pathways to avoid being recognized by the immune system, thereby shielding the tumor from immune attack. Checkpoint inhibitors such as agents targeting CTLA4 or programmed cell death protein 1 (PD1) are designed to enable the immune system to recognize tumor cells. In this setting, intra-tumoral TLR9 agonist administration may increase the tumor-infiltrating lymphocytes (TILs), and thereby potentiate anti-cancer activity of checkpoint inhibitors in the injected tumor as well as systemically.

Idera’s TLR9 agonists, IMO-2125 and IMO-2055, have been created using the company's proprietary chemistry-based discovery platform. IMO-2125 has been shown in various scientific presentations and publications to activate dendritic cells and induce interferon. Idera selected IMO-2125 to advance into clinical development in combination with checkpoint inhibitors based on this immunological profile. In previously completed clinical trials, subcutaneous administration of IMO-2125 was generally well tolerated in about 80 patients with hepatitis C. Idera has conducted further preclinical research evaluating the potential of IMO-2125 to enhance the anti-tumor activity of other checkpoint inhibitors in cancer immunotherapy with data being presented at several medical conferences during the past twelve months. The posters from these presentations can be found at

About Metastatic Melanoma
Melanoma is a type of skin cancer that begins in a type of skin cell called melanocytes. As is the case in many forms of cancer, melanoma becomes more difficult to treat once the disease has spread beyond the skin to other parts of the body such as by through the lymphatic system (metastatic disease). Melanoma accounts for only one percent of skin cancer cases, but causes a large majority of skin cancer deaths. The American Cancer Society estimates that in 2016, there will be 76,380 new cases of melanoma in the U.S., and about 10,130 will die of this disease.

About Idera Pharmaceuticals
Idera Pharmaceuticals is a clinical-stage biopharmaceutical company developing novel nucleic acid-based therapies for the treatment of certain cancers and rare diseases. Idera’s proprietary technology involves designing synthetic oligonucleotide-based drug candidates to modulate the activity of specific TLRs. In addition to its TLR programs, Idera has used its proprietary knowledge to create a third generation antisense technology platform which inhibits the production of disease-associated proteins by targeting RNA. To learn more about Idera, visit

Forward Looking Statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements, other than statements of historical fact, included or incorporated in this press release, including statements regarding the Company's strategy, future operations, collaborations, intellectual property, cash resources, financial position, future revenues, projected costs, prospects, plans, and objectives of management, are forward-looking statements. The words "believes," "anticipates," "estimates," "plans," "expects," "intends," "may," "could," "should," "potential," "likely," "projects," "continue," "will," and "would" and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Idera cannot guarantee that it will actually achieve the plans, intentions or expectations disclosed in its forward-looking statements and you should not place undue reliance on the Company's forward-looking statements. There are a number of important factors that could cause Idera's actual results to differ materially from those indicated or implied by its forward-looking statements. Factors that may cause such a difference include: whether interim results from a clinical trial, such as preliminary results reported in this release, will be predictive of the final results of the trial, whether results obtained in preclinical studies and clinical trials such as the preclinical data described in this release will be indicative of the results that will be generated in future clinical trials, including in clinical trials in different disease indications; whether products based on Idera's technology will advance into or through the clinical trial process on a timely basis or at all and receive approval from the United States Food and Drug Administration or equivalent foreign regulatory agencies; whether, if the Company's products receive approval, they will be successfully distributed and marketed; and such other important factors as are set forth under the caption "Risk Factors" in the Company's Annual Report and on Form 10-Q for the period ended September 30, 2016. Although Idera may elect to do so at some point in the future, the Company does not assume any obligation to update any forward-looking statements and it disclaims any intention or obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

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Source:Idera Pharmaceuticals, Inc.