March 22 (Reuters) - U.S. health regulators on Friday approved the first ever antibody that can counteract the effect of all types of toxins known to cause botulism, a muscle-paralyzing illness caused by a highly poisonous agent that health regulators regard as a bioterrorism threat.
The antidote, Botulism Antitoxin Heptavalent, is made by Winnipeg, Canada-based Cangene Corp, and was developed under a $427 million contract with the U.S. Department of Health and Human Services that makes the company eligible for a supplementary payment upon the treatment's FDA approval.
Cangene's treatment will be used on patients who show signs of botulism following suspected exposure to the seven types of botulinum nerve toxin that are known to cause the illness.
"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 Dr. Karen Midthun, director of FDA's center for biologics evaluation and research.
The botulinum toxin has been of concern to the U.S. military and its allies as a biowarfare weapon since World War Two and, in more recent times, as a potential bioterrorist threat to the public, according to U.S. health regulators.
The disease is usually spread by infected food, wounds or by a child consuming soil that contains the bacteria. It causes rapid muscle-loss and weakness that if left untreated, can lead to death due to respiratory failure.
A total of 140 cases of botulism were reported to the U.S. Centers for Disease Control and Prevention in 2011, of which 73 percent were infant botulism, 14 percent were foodborne and 9 percent were from infected wounds.
The FDA approval for Cangene's treatment, made from horse plasma, is based on tests only on animals, as it was not feasible or ethical to conduct such tests in humans, the FDA said.
The treatment, to be branded as BAT, was in 2007 added to the United States' national repository of antibiotics for use in case of a public health emergency.
BAT was designated an orphan drug by the FDA, which means it will get seven years of exclusivity from the date of its U.S. approval. A panel of advisers to the FDA last month voted to recommend approval of the product.
Cangene's shares are up about 50 percent since the beginning of this year, and closed at C$2.75 on the Toronto Stock Exchange on Friday.