PharmAthene, Inc., a biodefense company, develops and commercializes medical counter measures against biological and chemical threats in the United States. Its product candidates include SparVax, a recombinant protective antigen anthrax vaccine for post-exposure prophylaxis in conjunction with antibiotics and general use prophylaxis; Valortim, a human monoclonal antibody to protect against and treat human inhalational anthrax; and recombinant butyrylcholinesterase bioscavenger, a medical countermeasure for nerve agent poisoning by organophosphorous compounds comprising nerve gases and pesticides. The company serves the Biomedical Advanced Research and Development Authority, Chemical Biological Medical Systems, and the National Institute of Allergy and Infectious Diseases. It has collaboration with Bristol-Myers Squibb for developing Valortim; and strategic alliance with Nanotherapeutics, Inc. to develop biodefense programs. The company is headquartered in Annapolis, Maryland.