Experimental anthrax treatment denied approval

U.S. health regulators have decline to approve a new experimental treatment for anthrax infection from Human Genome Sciences, Inc.

The U.S. Food and Drug Administration has asked Human Genome Sciences for additional information relating to its biologics license application seeking approval of ABthrax, also known as raxibacumab.

A U.S. advisory panel had suggested last month that more studies were needed to that the ABthrax adds benefit beyond antibiotics alone. The FDA also raised questions about tests used to measure absorption rates of the drug in humans. The questionable tests made it impossible, the FDA said, to judge if the product was fit for approval.

In a statement, Human Genome Sciences said that the FDA's request seemed inconsistent with the agency's published final rule governing the development of new drugs. The company also plans on addressing the FDA's current questions.

The ABthrax project, developed under a government project to encourage new drugs and vaccines to fight potential bioweapons, was formed following the anthrax letter scare of 2001.

Sixty-five thousand doses of ABthrax have already been ordered by the U.S. government for a national stockpile of emergency medicines. Human Genome Sciences has received more than $160 million through sales of the drug to the government during the first two quarters of 2009.

Human Genome Sciences will receive an additional $10 million if ABthrax wins the FDA approval.