Immunomedics Develops Novel Dual System for Tumor Detection and Imaging

-- Pretargeting System Allows Dual Nuclear/Fluorescence Imaging During Cancer Surgery --

-- Results Reported at SNMMI 2013 Annual Meeting --

VANCOUVER, British Columbia, June 10, 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 the development of a pretargeting system that can detect and optically image a tumor during surgery. Results from this preclinical study were presented by Dr. Mark Rijpkema of the Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.

While tumor detection with specific radiotracers may be a useful tool for accurate localization and resection during surgery, these procedures could benefit from the addition of an optical tracer, since this may allow for more accurate delineation of the tumor and resection margins. Both tracers in such a dual modality approach need to show high specificity and a high tumor-to-background ratio (TBR).

The pretargeting system that the Company is pursuing involves the bispecific antibody, TF2, which targets the carcinoembryonic antigen (CEA), specifically CEACAM5, expressed in many human cancers, including breast, colorectal and lung cancer, and which is also being used in its IMMU-130 antibody-drug conjugate in clinical trials. Created by the Company's proprietary DOCK-AND-LOCK™ method, the bispecific antibody is currently in a number of clinical trials for pretargeted immunoPET imaging and radioimmunotherapy of patients with CEA-expressing cancers.

The other component of the pretargeting system is a small peptide bearing both the fluorescent dye, IRdye800CW, and a linker called DOTA for radiolabeling. Designated as RDC-018, this new peptide was derived from an earlier peptide, IMP288, that has been used successfully in pretargeting with a number of radioisotopes such as indium-111 (111In), yttrium-90, lutetium-177 and iodine-124.

The goal of this preclinical study was to assess the potential utility of this peptide for cancer detection by both optical (light) and radionuclide imaging, starting with an assessment of the radiolabeling procedure for RDC-018, and leading into in vivo biodistribution and tumor localization properties in a pretargeting setting compared to the 111In-IMP288. Animals bearing subcutaneous CEA-positive human colonic tumors and CEA-negative human renal cell tumors were used.

Biodistribution study of the RDC-018 peptide showed specific CEA-expressing tumor targeting with clearance via the kidneys similar to IMP288. Despite differences in renal uptake, RDC-018, with its ability to be imaged by both scintigraphic and optical methods, provided high tumor targeting and excellent TBR, illustrating the feasibility of this dual modality imaging approach.

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. 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, and a new method of delivering imaging and therapeutic agents selectively to disease, especially different solid cancers (colorectal, lung, pancreas, etc.), by proprietary, antibody-based, pretargeting methods. We believe that our portfolio of intellectual property, which includes approximately 223 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 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 our licensing partners for the further development of epratuzumab and veltuzumab 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.

CONTACT: Dr. Chau Cheng Senior Director, Investor Relations & Grant Management (973) 605-8200, extension 123 ccheng@immunomedics.comSource:Immunomedics, Inc.