Progress on Life-Saving Antibody for Inhalation Anthrax

The New England Journal of Medicine has published the results of two pivotal animal efficacy studies showing the life-saving potential of a human monoclonal antibody drug raxibacumab (ABthrax) in inhalation anthrax disease. The publication also included the results of human safety studies that supported the use of raxibacumab in the event of life-threatening inhalation anthrax disease. Raxibacumab is manufactured by Human Genome Sciences, Inc., which conducted the studies together with collaborators. "The results published today showed that a single dose of raxibacumab was highly effective as a treatment for inhalation anthrax in both rabbits and monkeys," said Dr. Sally D. Bolmer, senior author of the NEJM report and Senior Vice President, Development and Regulatory Affairs, Human Genome Sciences. "Raxibacumab acted quickly to provide a significant survival benefit to animals showing clinical signs of disease caused by exposure to a dose of aerosolized anthrax spores that was approximately 200 times the median lethal dose. We also note that the safety profile shown in healthy human volunteers provides support for use of raxibacumab in the clinical setting of immediately life-threatening inhalation anthrax disease." Raxibacumab represents a new way to address the anthrax threat. While antibiotics can kill the anthrax bacteria, they are not effective against the deadly toxins that the bacteria produce. Raxibacumab targets anthrax toxins after they are released by the bacteria into the blood and tissues. In an inhalation anthrax attack, people may not know they are infected with anthrax until the toxins already are circulating in their blood, and it may be too late for antibiotics alone to be effective.