Anthrax, caused by Bacillus anthracis, poses a potential threat as a bio terror agent because after inhalation, the spores rapidly cause bacteraemia and toxaemia. It produces a toxin consists of three proteins ie. Protective antigen (PA), oedema factor (EF) and lethal factor (LF). Protective antigen has a central role in pathophysiology of anthrax and it offers an excellent therapeutic target for treatment of anthrax. Raxibacumab is a recombinant, fully human, IgG1λ mAb directed against PA of B. Anthracis. It inhibits PA binding to the anthrax toxin receptor with and inhibits toxin-mediated cell death. It has been approved under animal rule or animal efficacy rule by the US-FDA which comes into play when it is not feasible or ethical to perform controlled clinical trials in humans. It has shown promising results in various animal studies which includes significantly improved survival rates in Raxibacumab group than non-raxibacumab group.