Anthrax Immune Globulin (AIG) – Therapeutic Product Candidate

• Disease Overview
• Product Candidate Description
• Market Opportunity and Current Treatment
• Development Status

Disease Overview

Anthrax bacteria are naturally occurring, and spores are found in soil throughout the world. Anthrax spores can withstand extreme heat, cold and drought for long periods without nutrients or air. Anthrax infections occur if the spores enter the body through a cut, abrasion or open sore, referred to as cutaneous anthrax, or by ingestion or inhalation of the spores. Once inside the body, anthrax spores germinate into bacteria that then multiply. Anthrax bacteria secrete three toxin proteins, protective antigen, lethal factor and edema factor, which are individually non-toxic but can become highly toxic if allowed to interact on the surface of human or animal cells.

Cutaneous anthrax, although rare in the United States, is the most common type of naturally acquired anthrax. Cutaneous anthrax is typically acquired through contact with contaminated animals and animal products. The fatality rate for untreated cases of cutaneous anthrax is estimated to be approximately 20%.

Inhalational anthrax is the most lethal form of anthrax. We believe that aerosolized anthrax spores are the most likely method to be used in a potential anthrax bioterrorism attack. Inhalational anthrax has been reported to occur from one to 43 days after exposure to aerosolized spores. Initial symptoms of inhalational anthrax are non-specific and may include sore throat, mild fever, cough, achiness or weakness, lasting up to a few days. After a brief period of improvement, the release of anthrax toxins may cause an abrupt deterioration of the infected person, with the sudden onset of symptoms, including fever, respiratory failure as the lungs fill with fluids and shock. Hemorrhagic meningitis is common. Death often occurs within 24 hours of the onset of advanced respiratory complications. The fatality rate for inhalational anthrax is estimated to be between 45% and 90%, depending on whether aggressive, early treatment is provided.

Product Candidate Description

We are developing an anthrax immune globulin (AIG) product candidate as a single dose intravenous therapeutic for treatment of patients with manifest symptoms of anthrax disease resulting from the release of anthrax toxins into the body. If successfully developed, we expect our AIG therapeutic to be prescribed for administration in these circumstances either as a monotherapy or in conjunction with an antibiotic. The National Institute of Allergy and Infectious Diseases (NIAID) has provided us grant funding to support non-clinical safety and efficacy studies and clinical trial planning.

Market Opportunity and Current Treatment

Currently, there are no approved products for the effective treatment of anthrax disease after anthrax toxins have been released into the body. In August 2004, the U.S. Department of Health and Human Services (HHS) issued an RFP seeking between 10,000 and 200,000 therapeutic courses of treatment of products to treat inhalational anthrax disease, including monoclonal antibodies, polyclonal antibodies (such as human immune globulin), and other protein therapeutic products. To date, HHS has awarded two contracts to other companies – one for anthrax immune globulin and one for a monoclonal antibody – and has exercised options under those contracts to purchase 10,000 doses of anthrax immune globulin and 20,000 treatment courses of the monoclonal antibody for the SNS. 

Announcements