NEW ORLEANS, La., June 16, 2008 (PRIME NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today reported that pretargeting with a bispecific antibody (bsMAb) and a peptide labeled with gallium-68 (Ga-68), a positron emission tomography (PET) sensitive radioisotope, produced excellent images in a human colorectal cancer model.
The bsMAb used in this study was TF2, an antibody constructed using the Company's proprietary protein engineering platform technology called the Dock-and-Lock (DNL). TF2 specifically targets the carcinoembryonic (CEA or CEACAM5) antigen expressed in many human cancers, and the histamine-succinyl-glycine (HSG) peptide, which in this study was labeled with Ga-68 for PET imaging.
Mice bearing human colorectal cancer transplants were pretargeted with 0.1-10 nmol of the DNL-construct and 16 hours later injected intravenously with 10 - 100 pmol of the HSG peptide. Four bsMAb to peptide ratios, 10:1, 25:1, 50:1 and 100:1, were studied.
High specific uptake of TF2 in the tumor was obtained at doses up to 2.5 nmol, while blood levels were sufficiently low. At a molar TF2 to HSG ratio of 25:1, maximal accumulation of the labeled peptide in the tumor was observed. Under these optimal conditions, the ratios of radioisotope uptake for tumor-to-blood and tumor-to-kidney were 590 and 6, respectively. The very high ratios produced excellent PET images of the tumor within 1 hour of Ga-68 injection.
"We are pleased with these preclinical results, which demonstrated that pretargeting with bispecific antibodies can be successfully applied to the imaging of cancer," said Cynthia L. Sullivan, President and CEO. Pretargeting with bispecific antibodies is a technology developed by IBC Pharmaceuticals, Inc., a majority-owned subsidiary of Immunomedics. The ultimate goal of IBC Pharmaceuticals is to offer cancer patients a more individualized treatment by combining improved molecular imaging with targeted therapy. Ms. Sullivan added, "In collaboration with IBC Pharmaceuticals and collaborating investigators, we are now planning to test this new technology in patients."
About Immunomedics
Immunomedics is a New Jersey-based biopharmaceutical company 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 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 have exclusively licensed our lead product candidate, epratuzumab, to UCB for the treatment of all autoimmune disease indications worldwide. Epratuzumab's most advanced clinical testing is for the treatment of systemic lupus erythematosus (SLE) and in non-Hodgkin's lymphoma (NHL). At present, there is no cure for lupus and no new lupus drug has been approved in the U.S. in the last 40 years. We have retained the rights for epratuzumab in oncology indications, and are advancing trials in lymphoma and in childhood acute lymphoblastic leukemia in cooperation with National Cancer Institute Study Groups. In addition, the Company is conducting clinical trials with intravenous veltuzumab in patients with NHL and immune thrombocytopenic purpura, subcutaneous veltuzumab in NHL and chronic lymphocytic leukemia (CLL), 90Y-epratuzumab for the therapy of patients with lymphoma, 90Y-hPAM4 combined with gemcitabine for pancreatic cancer therapy, and milatuzumab (anti-CD74 humanized antibody) as a therapy for patients with multiple myeloma, NHL, and CLL. We also have a majority ownership in IBC Pharmaceuticals, Inc., which is developing a novel Dock-and-Lock (DNL) methodology 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. The Company is working to advance this new technology into clinical testing, advancing the prospects of a personalized cancer therapy strategy. We believe that our portfolio of intellectual property, which includes approximately 116 patents issued in the United States and more than 295 other patents issued worldwide, protects our product candidates and technologies. For additional information on us, please visit our website at http://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, patent protection, out-licensing arrangements (including the timing and amount of contingent payments), forecasts of future operating results, 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 new product development (including clinical trials outcome and regulatory requirements/actions), our dependence on our licensing partner for the further development of epratuzumab for autoimmune 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.