Medarex Fully Human Anti-Anthrax Antibody Protects and Treats Anthrax Infection in Animal Model
Friday October 17, 6:01 am ET
Presentation at the Biodefense Vaccines, Therapeutics & Diagnostics Conference
PRINCETON, N.J., Oct. 17 /PRNewswire-FirstCall/ -- Medarex, Inc. (Nasdaq: MEDX - News) announced today that its fully human antibody against anthrax, MDX-1303, protected against inhalation anthrax at a dose ten-fold lower than previously tested in rabbits treated with the antibody, and that MDX-1303 reduced mortality even when administered 1-2 days after inhalation, once animals displayed signs suggestive of disease. These results are being presented today at the Biodefense Funding and Development Opportunities on Vaccines, Therapeutics & Diagnostics Conference in Washington, D.C.
The pre-clinical study was conducted by an independent party and was designed to determine the minimal amount of MDX-1303 required to provide protection and to determine the therapeutic activity of the antibody given at the time of anthrax inhalation. The results indicated that all doses tested were protective in rabbits exposed to lethal doses of anthrax spores by inhalation. The results also demonstrated that administration of MDX-1303 to rabbits 24 or 48 hours after exposure to anthrax could result in recovery and survival of the animals without the addition of antibiotics. These results suggest that the MDX-1303 antibody has the potential to be developed both as a prophylactic to protect patients at risk of exposure to anthrax and as a therapeutic for patients already showing signs and symptoms of anthrax infection.
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 in the Midwest.
"We believe that by demonstrating both prophylactic and therapeutic activities, MDX-1303 exhibits a unique and attractive antibody profile for use in the setting of anthrax exposure," said Israel Lowy, MD, PhD, Director of Infectious Diseases at Medarex. "Other anti-anthrax approaches have focused on antibodies that attach to the anthrax protective antigen but are only able to prevent unattached toxin from affecting living tissue. We deliberately searched for antibodies with the additional property of protecting cells even after anthrax toxin attachment. Further definition of therapeutic potential will require specialized animal testing to more closely approximate human disease."
"We are pleased to see such encouraging results and hope that the collaborative progress made by academic, government and biopharmaceutical industry organizations will encourage and enable the US government to rapidly implement the nation's biodefense initiatives," said Donald L. Drakeman, President and CEO of Medarex.
About MDX-1303
MDX-1303 is a fully human antibody against the inhalation anthrax, the most lethal form of illness in humans caused by the Bacillus anthracis bacterium, and targets a protein component of these lethal toxins known as the anthrax protective antigen. The anthrax protective antigen 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. MDX-1303 is designed to target anthrax protective antigen and protect the cells from damage by the anthrax toxins. |
