Immunomedics Reports Multiple Objective Responses in Solid Cancers With IMMU-132

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| Source: Immunomedics, Inc.

-- Partial Responses in Colorectal, Triple-Negative Breast, and Small-Cell-Lung Cancers --

-- Clinical Trial Expanding to Phase II Focusing on Select Tumor Types --

BOSTON, Oct. 22, 2013 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases, today announced that its newest antibody-drug conjugate (ADC), IMMU-132, has produced durable partial responses in three different cancer types in early phase of clinical evaluation.

Results from the multicenter, dose-escalation Phase I trial were presented by Dr. Alexander N. Starodub of the Indiana University Health Goshen Center for Cancer Care, Goshen, IN, at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics in Boston, Massachusetts.

In addition to the 3 partial responses observed by computed tomography (CT) using RECIST criteria, 15 patients also reported stable disease as their best response for an overall disease control rate of 86% in 21 patients with at least 1 CT assessment reported at the Conference. In terms of CT-confirmed tumor shrinkage, about half of the patients showed this result.

"We, as well as our clinical investigators, are very encouraged by these early promising results with IMMU-132 in this refractory, advanced cancer patient population with difficult-to-treat tumors that failed multiple prior therapies," commented Cynthia L. Sullivan, President and Chief Executive Officer of Immunomedics. "This is the first time these results have been presented at a scientific meeting after peer-review of the submitted abstract. The study has now transitioned to Phase II for additional safety and efficacy data in patients with certain tumor types using doses that were found active and tolerable in Phase I," Ms. Sullivan added.

At the time of reporting, a total of 25 patients with 12 different types of epithelial cancers have been enrolled into the Phase I trial. These patients had failed a median of 3 (range 1-6) prior standard therapies for their tumor types and were enrolled with disease progression. IMMU-132 was administered weekly for 2 consecutive weeks, followed by one week off, in 3-week cycles. Treatments may continue for up to 8 cycles until unacceptable toxicity or progression of disease. Currently, 10 patients are continuing treatments.

The major side-effects of IMMU-132 are neutropenia and controllable diarrhea, consistent with the toxicity experienced with irinotecan, the parent drug of SN-38, despite this agent releasing about 20-fold more SN-38 than when irinotecan is given.

This study was supported in part by Award Number R43CA171388 from the National Cancer Institute. The content is solely the responsibility of the Company and does not necessarily represent the official views of the National Cancer Institute or the National Institutes of Health.

About IMMU-132

IMMU-132 is composed of hRS7, a humanized antibody that binds to the trophoblast cell-surface antigen (TROP-2), also know as the epithelial glycoprotein-1 antigen (EGP-1). TROP-2 is expressed by many human tumors, such as cancers of the breast, cervix, colon and rectum, kidney, liver, lung, ovary, pancreas, and prostate, but with only limited expression in normal human tissues. hRS7 internalizes into cancer cells following binding to TROP-2, making it a suitable candidate for the delivery of cytotoxic drugs.

SN-38 is the active metabolite of irinotecan, which is a standard therapy for patients with metastatic colorectal cancer, but has major gastrointestinal and hematologic toxicity. By attaching SN-38 to tumor-targeting antibodies, delivery of SN-38 to the tumor may be increased several-fold while mitigating systemic toxicity. Preclinical studies have shown that the antibody-drug linkage was susceptible to cleavage in serum, with 50% of SN-38 released in ~1.0 day, leading to a locally enhanced concentration within the tumor site. In various animal models of human cancers, IMMU-132 significantly improved survival and tumor regression.

About Immunomedics

Immunomedics is a New Jersey-based biopharmaceutical company primarily focused on the development of monoclonal antibody-based products for the targeted treatment of cancer, autoimmune and other serious diseases. We have developed a number of advanced proprietary technologies that allow us to create humanized antibodies that can be used either alone in unlabeled or "naked" form, or conjugated with radioactive isotopes, chemotherapeutics, cytokines or toxins, in each case to create highly targeted agents. Using these technologies, we have built a pipeline of therapeutic product candidates that utilize several different mechanisms of action. Our lead product candidate, epratuzumab, is currently in two Phase III clinical trials in lupus. In oncology, we are planning to launch a Phase III pivotal trial for clivatuzumab labeled with a radioisotope in advanced pancreatic cancer patients. Other solid tumor therapeutics in Phase II clinical development include 2 antibody-drug conjugates, labetuzumab-SN-38 (IMMU-130) and hRS7-SN-38 (IMMU-132). We also have a majority ownership in IBC Pharmaceuticals, Inc., which is developing a novel DOCK-AND-LOCK™ (DNL™) method with us for making fusion proteins and multifunctional antibodies. DNL™ is being used particularly to make bispecific antibodies targeting cancers and infectious diseases as a T-cell redirecting immunotherapy, as well as bispecific antibodies for next-generation cancer and autoimmune disease therapies. We believe that our portfolio of intellectual property, which includes approximately 231 active patents in the United States and more than 400 foreign patents, protects our product candidates and technologies. Our strength in intellectual property has resulted in the top-10 ranking in the 2012 IEEE Spectrum Patent Power Scorecards in the Biotechnology and Pharmaceuticals category. For additional information on us, please visit our website at www.immunomedics.com. The information on our website does not, however, form a part of this press release.

This release, in addition to historical information, may contain forward-looking statements made pursuant to the Private Securities Litigation Reform Act of 1995. Such statements, including statements regarding clinical trials, out-licensing arrangements (including the timing and amount of contingent payments), forecasts of future operating results, potential collaborations, and capital raising activities, involve significant risks and uncertainties and actual results could differ materially from those expressed or implied herein. Factors that could cause such differences include, but are not limited to, risks associated with any cash payment that the Company might receive in connection with a sublicense involving a third party and UCB, which is not within the Company's control, new product development (including clinical trials outcome and regulatory requirements/actions), our dependence on UCB for the further development of epratuzumab for non-cancer indications, competitive risks to marketed products and availability of required financing and other sources of funds on acceptable terms, if at all, as well as the risks discussed in the Company's filings with the Securities and Exchange Commission. The Company is not under any obligation, and the Company expressly disclaims any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise.

For More Information:
Dr. Chau Cheng
Senior Director, Investor Relations & Grant Management
(973) 605-8200, extension 123
ccheng@immunomedics.com