Oral Smallpox Treatment Gains FDA NDA Acceptance and Priority Review

The US Food and Drug Administration (FDA) has accepted SIGA Technologies, Inc's New Drug Application (NDA) for its oral formulation of the smallpox medication, tecovirimat (TPOXX). The treatment is a novel small molecule antiviral therapy for smallpox infection. The FDA has granted priority review to the application, which means that they should reach a decision in approximately 6 months. The target final action date is August 8, 2018.

Smallpox was deemed eradicated throughout the world in 1980 because of the availability of a protective vaccine; however, research on the highly contagious virus continues to this day given the potential for it to be used in biological warfare. Those individuals born after 1972, when the United States stopped routinely administering that vaccine, would be particularly vulnerable to an outbreak. Should SIGA's drug be approved, it will be the first treatment available for the deadly disease.

The development of tecovirimat has been funded by the US government’s Biomedical Advanced Research and Development Authority (BARDA). According to a press release from SIGA, “tecovirimat was developed under the FDA 'Animal Rule,' in which efficacy endpoints are determined in animal studies, and human clinical studies are conducted to determine safety and confirm dosing. There have been no drug-related serious adverse events during the development of oral tecovirimat."

Pursuant to a contract with BARDA, SIGA has successfully delivered 2 million courses of tecovirimat to the Strategic National Stockpile. The anticipated shelf-life for the drug is 7 years.

In April 2017, we covered news that SIGA had just completed enrollment and dosing in the final cohort of a phase 1 trial of an intravenous (IV) formulation of tecovirimat.