|
| ||||||||
| ||||||||
|
Biosecurity BriefingNIAID and BARDA Award Funding to SIGA Technologies for Orthopoxvirus AntiviralBy Christine SooHoo, September 8, 2008 On September 3, 2008, SIGA Technologies, Inc., announced that the National Institute of Allergy and Infectious Diseases (NIAID) and the Department of Health and Human Services (HHS) Office of the Biomedical Advance Research and Development Authority (BARDA), awarded the pharmaceutical company a $55 million contract to fund the development of additional formulations and smallpox-related indications for its antiviral drug ST-246TM.1 According to SIGA phase 1 clinical study published in Antimicrobial Agents and Chemotherapy in March 2008, this new funding enables the formulation and advanced development of a new ST-246TM drug product and increases the utility of the existing oral formulation of ST-246TM as a smallpox medical countermeasure.2 The study was conducted involving healthy human volunteers, and it showed that oral administration of ST-246TM prevents the spread of orthopoxvirus by inhibiting the egress of the virions. The study also showed that the antiviral is “generally tolerated with no serious adverse events.”1 In addition to its therapeutic applications, SIGA proposed that ST-246TM could have preventative applications as a prophylactic treatment for orthopoxviruses or as a supplement to vaccination. The smallpox vaccine currently stored in the Strategic National Stockpile (SNS) is associated with complications such as progressive vaccinia and eczema vaccinatum, which can be serious and even fatal.3 Combining vaccination with administration of ST-246TM could reduce complications associated with smallpox vaccination, as was demonstrated in 2007. A child with eczema vaccinatum was given ST-246TM, after the FDA approved the drug under the Emergency Use Authorization (EUA). EUA authorizes the use of drugs or products that may be effective in the prevention, diagnosis or treatment of serious or life-threatening diseases or conditions that can be caused by specified biological, chemical, radiological or nuclear agents. The child in that case recovered after receiving ST-246TM along with other medications.2 SIGA has also developed, and is awaiting FDA approval for, a manufacturing process to create substantial quantities of the antiviral drug for stockpiling.4 More studies are needed in order for ST-246TM to receive regulatory approval. Future activities also include formulation development, animal efficacy and human safety evaluations, and manufacturing.2 There are no antiviral treatments for smallpox currently approved by the FDA. ST-246TM’s efficacy is not limited to the smallpox virus. It is also been shown to be effective against other orthopoxviruses such as cowpox and monkeypox. However, variola major, the causative agent of smallpox, is the only orthopoxvirus that is considered a Category A biological threat agent by the U.S Centers for Disease Control and Prevention (CDC). References
|