Immunomedics announced the development of IMMU-114, a humanized monoclonal antibody directed against an immune response target, HLA-DR, for the potential treatment of cancer

DENVER,CO, USA | April 20, 2009 | Immunomedics, Inc. (Nasdaq:IMMU), a biopharmaceutical company focused on developing monoclonal antibodies to treat cancer and other serious diseases, today announced the development of IMMU-114, a humanized monoclonal antibody directed against an immune response target, HLA-DR, for the potential treatment of cancer. Preclinical results on the evaluation of this antibody were presented at the 100th Annual Meeting of the American Association for Cancer Research (AACR).

The in vitro studies examined the reactivity and cytotoxicity of IMMU-114 on a panel of leukemia cell lines including acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), chronic myelogenous leukemia (CML), hairy cell leukemia and mantle cell lymphoma (MCL). Results demonstrated that IMMU-114 may be useful in the treatment of MCL, ALL, hairy cell leukemia, and CLL. Previously, in a paper published by the Company in the October 15, 2006, issue of Blood, the antibody was also shown to exhibit in vitro and in vivo cytotoxicity on a number of human lymphoma cell lines.

"We continue to expand our repertoire of promising humanized antibodies that have potential applications for the therapy of cancer and inflammatory diseases," stated Cynthia L. Sullivan, President and CEO. "Although other HLA-DR antibodies have been developed," she continued, "IMMU-114 is distinguished by having a different immunoglobulin class, IgG4, which does not function by the usual effector-cell activities, such as complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). As a result, we believe it is less toxic to patients. We are evaluating its potential activity against certain solid cancers and autoimmune diseases, and will consider it for future clinical development," Ms. Sullivan concluded.

HLA-DR, human leukocyte antigen-DR, is a class II major histocompatibility complex (MHC) cell surface receptor. The antigen is expressed at high levels on a range of hematological malignancies. As a result, there has been considerable interest in its development as a target for antibody-based lymphoma therapy. However, because the antigen is expressed on normal as well as tumor cells, safety concerns have been raised regarding the clinical use of HLA-DR-directed antibodies.

About IMMU-114

IMMU-114 is a humanized IgG4 antibody that targets the HLA-DR antigen. Constructed by complementarity-determining region grafting, the IgG4 antibody was generated to fill the need for an agent that is able to kill tumor cells without CDC or ADCC, thereby reducing the reliance on intact immunological systems in the patient as well as lowering the effector mechanism-related toxicity. Moreover, because ADCC and CDC are believed to play a major role in side effects of monoclonal antibody therapy, the abrogation of the effector-cell functions of IMMU-114 may make it an attractive clinical agent.

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 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 134 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 www.immunomedics.com. The information on our website does not, however, form a part of this press release.

SOURCE: Immunomedics, Inc.