New Anthrax Drug Effectiveness Similar to Antibiotics in Animal Studies

Two animal studies of a new drug, ABthrax, showed that it has comparable effectiveness to existing anthrax antibiotics, Reuters reported Friday (see GSN, Oct. 5).

Maryland-based Human Genome Sciences Inc. formulated ABthrax, also called raxibacumab, and tested it on rabbits and monkeys. Though the product produced better results than a placebo, the Food and Drug Administration reported that "it is still unknown how well these models and results predict efficacy in humans."

The agency is expected to request tomorrow that an advisory board consider whether ABthrax's advantages exceed possible dangers in treating people who have been exposed to inhalational anthrax.

Food and Drug Administration drug reviewers reported that antibiotics applied alone performed comparably to the addition of one intravenous shot of ABthrax to the antibiotics. The advisory panel is expected to consider whether ABthrax could get in the way of antibiotics' effectiveness or if more information is required to determine if the new drug has any medical value.

"Given the high efficacy of the (antibiotic) arms" in the two animal studies, "the added benefit of raxibacumab ... could not be determined," wrote FDA reviewers.

Washington has placed an order for 65,000 doses of ABthrax for the country's emergency medicines reserve. Human Genome Sciences Inc. announced in July that it had earned $160 million from government sales of ABthrax for the first half of the year. If ABthrax receives FDA approval, the company is expected to be paid another $10 million (Lisa Richwine, Reuters, Oct. 23).

October 26, 2009
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Two animal studies of a new drug, ABthrax, showed that it has comparable effectiveness to existing anthrax antibiotics, Reuters reported Friday (see GSN, Oct. 5).