Anthrax is a highly contagious and potentially fatal human disease caused by 
Bacillus anthracis, an aerobic, Gram-positive, spore-forming rod-shaped 
bacterium with worldwide distribution as a zoonotic infection in herbivore 
animals. Bioterrorist attacks with inhalational anthrax have prompted the 
development of more effective treatments. Antibodies against anthrax toxin have 
been shown to decrease mortality in animal studies. Raxibacumab is a recombinant 
human monoclonal antibody developed against inhalational anthrax. The drug 
received approval after human studies showed its safety and animal studies 
demonstrated its efficacy for treatment as well as prophylaxis against 
inhalational anthrax. It works by preventing binding of the protective antigen 
component of the anthrax toxin to its receptors in host cells, thereby blocking 
the toxin's deleterious effects. Recently updated therapy guidelines for 
Bacillus anthracis recommend the use of antitoxin treatment. Raxibacumab is the 
first monoclonal antitoxin antibody made available that can be used with the 
antibiotics recommended for treatment of the disease. When exposure is 
suspected, raxibacumab should be given with anthrax vaccination to augment 
immunity. Raxibacumab provides additional protection against inhalational 
anthrax via a mechanism different from that of either antibiotics or active 
immunization. In combination with currently available and recommended therapies, 
raxibacumab should reduce the morbidity and mortality of inhalational anthrax.