Wed Mar 25, 2015 9:14am EDT

Emergent BioSolutions Inc said the U.S. Food and Drug Administration approved its treatment for inhaled anthrax, triggering a $7 million milestone payment from the Department of Health and Human Services (HHS).

 

Anthrax has been used as a weapon for nearly a century and is still considered one of the most likely agents to be used in biological warfare. A small supply of the deadly pathogen can infect a large number of people, according to the Centers for Disease Control and Prevention (CDC).

 

Emergent Bio developed the treatment, Anthrasil, as part of a $160 million contract it signed in 2005 with the Biomedical Advanced Research and Development Authority (BARDA), a part of the HHS.

 

The drug, which is approved in combination with other antibacterials, is already being stored in the U.S. Strategic National Stockpile, the company said on Wednesday.

 

Anthrasil is a sterile solution that targets the anthrax toxins of Bacillus anthracis, the bacteria behind the infection.

 

The drug is made using plasma from healthy, screened donors who have been immunized with Emergent Bio's Anthrax vaccine, BioThrax, the only FDA-licensed vaccine for the disease.

 

Earlier this week, the HHS signed a $31 million agreement with Maryland-based Emergent Bio to develop a vaccine that requires only two doses to confer immunity. BioThrax currently needs three doses.

 

Humans may contract the disease from livestock, wild animals, or animal products. Person-to-person transmission is highly unlikely, while signs and symptoms may change depending on how the disease is contracted.

 

Inhalation of bacterial spores is one of the deadliest ways in which the disease strikes. The spores of Bacillus anthracis are widely prevalent in nature, but can also be produced in a laboratory.

 

It could take weeks of exposure before symptoms appear. Initial signs include flu-like symptoms and coughing up blood, but breathing trouble, shock and meningitis could appear as the disease progresses.

 

The United States has witnessed a spate of anthrax scares. A bioterror lab mishap last June potentially exposed government workers to live anthrax at three labs in Atlanta.

 

In 2004, a Maryland lab accidentally sent a batch of live anthrax to a children's hospital in California. Powdered anthrax spores were deliberately put into letters mailed through the U.S. postal system in 2001.

 

Emergent Bio's shares closed at $29.30 on the New York Stock Exchange on Tuesday.