Inhalation anthrax treatment, raxibacumab, gets FDA approval
The U.S. Food and Drug Administration today approved GlaxoSmithKline’s raxibacumab injection to treat inhalation anthrax, a lethal form of the infectious disease caused by breathing in the spores of the bacterium Bacillus anthracis, according to an FDA press release Friday.
The approval comes just a month after the Anti-Infective Drugs Advisory Committee for FDA recommended its approval.
The drug, raxibacumab injection, is a monoclonal antibody targeting the protective antigen (PA) component of the lethal toxin of Bacillus anthracis and was developed for the treatment of inhalation anthrax.
The FDA granted raxibacumab fast track designation, priority review, and orphan product designation. The drug demonstrated the potential to fill an unmet medical need, has the potential to provide safe and effective treatment where no satisfactory alternative therapy exists, and is intended to treat a rare disease, respectively.
Raxibacumab is the first monoclonal antibody approved under the FDA’s Animal Efficacy Rule, which allows efficacy findings from adequate and well-controlled animal studies to support FDA approval when it is not feasible or ethical to conduct trials in humans. In this case, because inhalational anthrax is a rare and lethal disease, it is not possible to conduct adequate efficacy trials in humans.
According to the National Institutes of Health, inhaled anthrax is particularly deadly. Although the spores are dormant when breathed in, they germinate when exposed to a warm, moist environment, such as the lungs. Not all particles are small enough to pass into the alveoli, or air sacs, but those that do begin to multiply and may spread to the lymphatic system. When the spores germinate in the lymph nodes, several toxins are released.
Raxibacumab’s effectiveness for inhalational anthrax was demonstrated in one study in monkeys and three studies in rabbits.
The safety of raxibacumab was evaluated in 326 healthy human volunteers. Common side effects included rash, extremity pain, itching and drowsiness.
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