Medarex Fully Human Antibody Demonstrates Activity Against Anthrax in Animal Model

PRINCETON, N.J. -- Medarex, Inc. announced today the results of pre-clinical studies of its fully human antibody against anthrax. In a standard pre-clinical animal study conducted by an independent party, rabbits were exposed to lethal doses of anthrax spores by inhalation, received varying doses of antibody, and were observed for two weeks. All of the rabbits in a control group that did not receive the antibody died within days of exposure. In contrast, and at all dose levels tested, the antibody protected the rabbits from the lethal effects of the anthrax bacteria and its toxins to the two-week study endpoint.

The pre-clinical study, under a cooperative research and development agreement with the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and Dartmouth Medical School, was conducted at a separate, specially equipped facility.

Inhalation anthrax is the most lethal form of illness in humans caused by the Bacillus anthracis bacterium. The bacteria produce several lethal toxins that lead to an overwhelming pneumonia and shock in exposed individuals. This late stage of the illness frequently does not respond to standard antibiotic therapy and is often fatal. The anthrax protective antigen, a protein component of these lethal toxins, initiates the onset of the illness by attaching to cells in the infected person, and then facilitates the entry of additional destructive toxins into the cells. The fully human antibody in development by Medarex targets the anthrax protective antigen and is designed to protect the cells from damage by the anthrax toxins. The antibody was generated by Medarex's UltiMAb Human Antibody Development System.

"If we continue to see such encouraging results following further evaluations of our antibody, we could file an IND for this product candidate as early as 2004," said Donald L. Drakeman, president and CEO of Medarex.

According to the Centers for Disease Control and Prevention (CDC), anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in hoofed mammals and can also infect humans. Symptoms of disease vary depending on how the disease was contracted, but usually occur within seven days after exposure. The serious forms of human anthrax are inhalation anthrax, cutaneous anthrax, and intestinal anthrax. Initial symptoms of inhalation anthrax infection may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax is often fatal.

USAMRIID, located at Fort Detrick, Md., is the lead medical research laboratory for the U.S. Biological Defense Research Program, and plays a key role in national defense and in infectious disease research. The Institute's mission is to conduct basic and applied research on biological threats resulting in medical solutions (such as vaccines, drugs and diagnostics) to protect the warfighter. USAMRIID is a subordinate laboratory of the U.S. Army Medical Research and Materiel Command.

Dartmouth Medical School (DMS) is dedicated to advancing health through the discovery and dissemination of knowledge. The nation's fourth oldest medical school, founded in 1797, DMS focuses on excellence in biomedical research and education, patient care and service. The Medical School encompasses 16 clinical and basic science departments, the Center for the Evaluative Clinical Sciences, the Norris Cotton Cancer Center, the C. Everett Koop Institute and an array of multidisciplinary partnerships with Dartmouth College and Dartmouth-Hitchcock Medical Center to support innovative research, promising therapy trials, learning and service. Research includes programs in infectious diseases and their prevention, immunology, cancer, cell and molecular biology, genetics, ethics, neurosciences, public health and medical outcomes. Dartmouth Medical School researchers with expertise in novel ways to treat and prevent infections, with support from Dartmouth's Institute for Security Technology Studies, have teamed up with USAMRIID and Medarex to research therapeutics for the treatment of anthrax.

Medarex is a biopharmaceutical company focused on the discovery and development of therapeutics to treat life-threatening and debilitating diseases. Medarex's UltiMAb Human Antibody Development System is a unique combination of human antibody technologies that Medarex believes enables the rapid creation and development of fully human antibodies for a wide range of potential disease targets for therapeutic antibody products, including products for the treatment of cancer, inflammation, autoimmune and infectious diseases. Medarex's product pipeline is based on a variety of therapeutic antibody products developed through the use of its UltiMAb technology.

Source: Medarex, Inc.