FDA Advisory Committee Votes Unanimously in Support of TPOXX

The US Food and Drug Administration (FDA)’s Antimicrobial Drugs Advisory Committee has voted unanimously that the benefits of TPOXX, a small molecule antiviral treatment for smallpox, outweigh its risks.

In February, the FDA granted priority review to the application. TPOXX, also known as tecovirimat and ST-246, is a patented oral drug that is easy to store, transport, and administer. “There could be several potential uses for an effective antiviral drug to treat orthopoxvirus infections: to reduce mortality and morbidity in those infected with smallpox (or another orthopoxvirus) virus, to protect the non-immune who risk developing smallpox following virus exposure, and as an adjunct to the smallpox vaccine in order to reduce the frequency of serious adverse events due to the live virus used for vaccination,” according to SIGA Technologies.

The drug received funding by the US government’s Biomedical Advanced Research and Development Authority (BARDA). Furthermore, it was developed under the FDA ‘Animal Rule,’ which means that efficacy endpoints were determined in animal studies, and then human clinical trials are conducted to assess safety and confirm dosing.

“We are pleased that the advisory panel believes strongly in the benefits of TPOXX. We are confident that the robust data package and safety profile with no drug-related serious adverse events positions TPOXX for favorable FDA review of its pending New Drug Application (NDA),” Dr. Phil Gomez, chief executive officer of SIGA Technologies, Inc. said in a recent statement.

“The support of the independent medical experts that comprise the advisory committee panel provides valuable additional feedback reflecting the strength of our application for TPOXX. We believe that safety and efficacy data contained in the NDA support TPOXX’s future use as a medical countermeasure in response to a smallpox outbreak,” he added.

Smallpox is thought to date back to the 3rd century BCE in the Egyptian Empire, although its origins remain largely unknown. As civilizations grew throughout history, the disease spread across the globe, leaving devastation and death in its wake. Despite the fact that the last natural outbreak of the disease occurred back in 1949 and the World Health Assembly deemed it completely eradicated due to successful vaccination efforts, as the frozen Siberian tundra continues to melt, the chances of the deadly virus making a comeback are not that far-fetched.

The FDA’s target final action date for the oral TPOXX NDA is projected to be on August 8, 2018.

Already, under Project Bioshield, BARDA has obtained about 2 million courses of TPOXX, and the courses have been delivered to the Strategic National Stockpile.