New Drug Fights Anthrax Toxin

July 9 -- WEDNESDAY, July 8 (HealthDay News) -- Scientists report that experiments in animals show that a new, monoclonal antibody drug might safely cure anthrax poisoning in humans.

Although antibiotics can kill the anthrax bacteria, they are not effective in killing the toxins produced by the bacteria. The new drug, raxibacumab, specifically targets those toxins once they enter the bloodstream. After an anthrax attack, people may not know they are infected until the toxins are circulating in their blood, and it may be too late for antibiotics alone to be effective, the researchers explained.

"This drug strengthens America's arsenal against bioterrorism that would work in the face of antibiotic-resistant anthrax bacterium," said lead researcher Sally Bolmer, senior vice president of development and regulatory affairs at Human Genome Sciences Inc., the company that developed raxibacumab.

The drug works differently than antibiotics, Bolmer noted. "It [also] acts more quickly than vaccines. So, it is complementary to both of those," she said.

"If we administered it at the time the animals were exposed to anthrax or even waited until their symptoms developed, we could improve survival in rabbits and monkeys," she said.

The same doses of the drug were given to humans and the drug was well-tolerated, Bolmer added.

The report is published in the July 9 issue of the New England Journal of Medicine.

In the study, researchers showed that a single dose of raxibacumab was an effective treatment for inhalation anthrax in both rabbits and monkeys.

The drug provided a significant survival benefit to animals showing signs of the disease. The animals were exposed to a dose of anthrax approximately 200 times the lethal dose, the researchers said.

In addition, raxibacumab was safe when given to human volunteers and could be used in a clinical setting in cases of life-threatening inhalation anthrax disease, Bolmer said.