The U.S. Food and Drug Administration last week announced approval of a new indication for Emergent Biosolutions’ BioThrax to prevent disease following suspected or confirmed exposure to Bacillus anthracis, the bacterium that causes anthrax disease.
The vaccine’s new use is approved for people 18 through 65 years of age in conjunction with recommended antibiotic treatment.
Anthrax disease, especially the inhalation form, is often fatal if not promptly treated. Anthrax is considered one of the more likely agents to be used in a biological attack, primarily because its spores are very stable and easy to disperse. Although it is rare, people may contract anthrax disease through natural exposures, such as contact with infected animals or contaminated animal products.
The ability of BioThrax to increase the probability of survival after stopping post-exposure antibiotic treatment was assessed in rabbits. Rabbits treated with both antibiotics and BioThrax had a survival rate of 70 to 100 percent, depending on the vaccine dose administered. In contrast, in two studies of rabbits that received only antibiotic treatment, survival rates were 44 and 23 percent respectively.
BioThrax is the first vaccine to receive approval based on the Animal Rule. The Animal Rule allows animal efficacy data to be used as a basis for approval when human efficacy studies are not ethical or feasible.
“With today’s approval of BioThrax, we now have a vaccine that can be used, together with antibiotic treatment, to prevent disease after exposure to anthrax spores,” said Karen Midthun, M.D., director of the FDA’s Center for Biologics Evaluation and Research
Licensure of BioThrax for post-exposure prophylaxis is the culmination of a 10-year collaborative effort between Emergent, the Biomedical Advanced Research and Development Authority (BARDA) and the National Institute of Allergy and Infectious Diseases.
“Our BioThrax enhancement program is evidence of our successful partnership with the U.S. government to support the nation’s biosecurity efforts,” said Adam Havey, Executive Vice President and President, Biodefense Division at Emergent BioSolutions. “Over the years, we have enhanced the features of BioThrax to include intra-muscular route of administration, a streamlined vaccination schedule, extended shelf life, and now a post-exposure prophylaxis indication. We are proud of these achievements and look forward to continuing to supply the stockpile with this important medical countermeasure.”
Source: FDA press release, adapted.