SAN FRANCISCO, Dec. 9, 2008 (GLOBE NEWSWIRE) -- Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced that combining milatuzumab with rituximab prolonged survival of animals injected with human mantle cell lymphoma cells. Results from this preclinical study were reported in an oral presentation at the 50th annual meeting of ASH by Dr. Lapo Alinari of the Comprehensive Cancer Center, The Ohio State University, Columbus, OH.
Mantle cell lymphoma (MCL) is an aggressive form of non-Hodgkin's lymphoma that is incurable with current chemotherapeutic approaches. Treatment with antibodies such as rituximab as a single agent or in combination with chemotherapy has demonstrated only modest activity. "Identifying new therapies for this disease is therefore of great importance," says Dr John C. Byrd, Associate Director for Translational Research of The Ohio State University Comprehensive Cancer Center and co-investigator on this project. Milatuzumab is Immunomedics' proprietary humanized antibody that recognizes CD74, an integral membrane protein which has been implicated in promoting survival and growth, and is expressed on malignant B cells. In preclinical studies, milatuzumab has shown promising activity against several human B-cell lymphoma cell lines, but has not been evaluated in MCL. Since milatuzumab and rituximab target distinct antigens lacking known association, the goal of this study is to investigate the effects of combining the two antibodies in MCL cell lines, patient samples, and in a preclinical model of MCL that was established in the laboratory of the senior investigator on this project, Dr. Robert Baiocchi, Assistant Professor of Medicine and member of the The Ohio State Comprehensive Cancer Center.
The MCL cell lines and the tumor cells from MCL patients used in this study all express abundant surface CD74. Incubation of the cell lines with immobilized milatuzumab or rituximab resulted in cell death, which was significantly enhanced when the two antibodies were combined. Anti-tumor activities were compared in a human MCL model in animals depleted of natural killer cells. The mean survival for the combination-treated group was 55 days, which is considerably longer than 33 days for the control group, 35.5 days and 45 days for the milatuzumab-treated and the rituximab-treated groups, respectively. No overt toxicity from milatuzumab or the combination regimen was noted.
"These preliminary results provide justification for further evaluation of milatuzumab and rituximab in combination in MCL. A confirmatory study with a larger group of mice and detailed mechanistic studies are now underway," commented Dr. Alinari.
About Milatuzumab
Milatuzumab is a humanized anti-CD74 antibody constructed using the same constant regions of the heavy and light chains as epratuzumab, whose safety has been demonstrated in clinical trials of patients with B-cell malignancies and autoimmune disorders. Milatuzumab was found to block the overexpression of CD74 in chronic lymphocytic leukemia (CLL) cells, which led to increased cell death. Preclinical studies have also shown that milatuzumab can inhibit the growth of human multiple myeloma (MM) and lymphoma cells in culture and in immune-depressed mice when used alone or in combination with drugs approved for the treatment of MM. Milatuzumab is being investigated as a naked antibody in 3 Phase I/II studies for the treatment of MM, non-Hodgkin's lymphoma, and CLL, and has received FDA orphan drug designation for the therapy of MM and CLL. Milatuzumab conjugated with doxorubicin will be studied in upcoming clinical trials in multiple myeloma.
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 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) 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. We believe that our portfolio of intellectual property, which includes approximately 123 patents issued in the United States and more than 300 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, 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 partners for the further development of epratuzumab for autoimmune indications 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.