FDA Approves First Heptavalent Botulism Antitoxin


March 25, 2013

The US Food and Drug Administration (FDA) last Friday approved the first botulism antitoxin to neutralize all 7 known botulinum nerve toxin serotypes — valuable versatility for a drug in the nation's emergency medicine cabinet against a bioterrorist attack.

The heptavalent botulism antitoxin (BAT, Cangene) had been available on an investigational basis from the Centers for Disease Control and Prevention (CDC). Cangene began supplying doses of BAT to the US Strategic National Stockpile in 2007 under a $427 million contract with the Department of Health and Human Services, according to a company press release. The CDC will distribute the stockpiled antitoxin.

"This product approval meets an urgent unmet medical need for the treatment of sporadic cases of life-threatening botulism and provides a medical countermeasure should botulinum nerve toxins be used in a terrorism event," said Karen Midthun, MD, director of the FDA's Center for Biologics Evaluation and Research, in a press release.

Derived from horse plasma, the heptavalent antitoxin is the only drug available for treating botulism in adults, and for botulism in infants caused by nerve toxins other than types A and B.

The FDA established the efficacy of the antitoxin in animal studies. Performing such studies in humans would not have been feasible or ethical, according to the agency.

The antitoxin proved safe in a study of 40 healthy volunteers as well as in the experimental treatment of 228 patients in a program administered by the CDC. Headache, fever, chills, rash, itching, and nausea were the most observed adverse events. The antitoxin can trigger allergic reactions and delayed hypersensitivity reaction in patients sensitive to horse proteins.

More information on last week's FDA announcement is available on the agency's Web site.