
SIGA - Model TPOXX - Vaccines for Smallpox
Oral TPOXX® (tecovirimat) is the first drug approved by the U.S. Food and Drug Administration (FDA) that is specifically indicated for the treatment of smallpox disease in adults and pediatric patients weighing at least 13 kg. (Prescription Label) TPOXX® inhibits viral maturation of variola virus (the virus that causes smallpox) and other poxviruses by preventing the formation of a secondary viral envelope. In the absence of this envelope, viral particles remain inside the cell and cannot spread to and infect other cells. The most frequently reported adverse reactions were headache and nausea.
TPOXX® is among the first novel small molecule therapies delivered to the Strategic National Stockpile (SNS) under Project BioShield, a U.S. government program designed to accelerate the research, development, purchase, and availability of effective medical countermeasures against chemical, biological, radiological, and nuclear (CBRN) agents. As the first antiviral agent specifically indicated for the treatment of smallpox, TPOXX® would play a critical role in responding to a smallpox bioterror attack.
Following U.S. approval, Health Canada also authorized the use of oral TPOXX® for the treatment of human smallpox disease in adults and pediatric patients weighing at least 13 kg. Oral TPOXX® is supplied to both the Canadian Department of National Defence (DND) and the Public Health Agency of Canada (PHAC) for stockpiling as a key countermeasure. (Prescription Label)
Oral tecovirimat was later approved by the European Medicines Agency (EMA) and the Norwegian Medicines Agency for the treatment of smallpox, monkeypox, cowpox, and vaccinia complications following vaccination against smallpox in adults and children with body weight at least 13kg. (Prescription Label)