In its announcement, the US Food and Drug Administration (FDA) explained it had encouraged the development of a treatment for smallpox due to the ‘risk of bioterrorism’.
The variola virus, as it is also known, was labelled officially eradicated by the World Health Organization (WHO) in 1980, with the last case being diagnosed in 1977.
However, samples of the virus have been retained for scientific purposes and there has been concern that an accident, or an intentional effort, could reintroduce smallpox to humans and cause significant loss of life.
The smallpox virus killed approximately 300 million in the 20th century before extensive vaccination managed to stop it from spreading.
Developing a treatment without any cases
With nobody carrying the virus to test its treatment, a spokesperson for SIGA Technologies explained to us how the treatment came into being: “TPOXX was developed under the Animal Rule. FDA approval is based on safety data from 12 clinical trials of oral TPOXX in over 700 healthy human volunteers, which showed no drug-related serious adverse events.
“Four pivotal trials in non-human primates (NHPs) and two pivotal trials in rabbits demonstrated that TPOXX significantly reduced both mortality and viral load in NHPs infected with monkeypox virus and in rabbits infected with rabbitpox virus.”
SIGA worked alongside a number of US government departments to create the treatment, including Biomedical Advanced Research and Developed Authority (BARDA).
The spokesperson for SIGA commented that they “believe the approval of TPOXX is proof that public-private partnerships work when the partners are committed to a focused mission.”
SIGA revealed that the US ordered and had delivered two million courses of the treatment to the Strategic National Stockpile – a repository of antibiotics, vaccines and antitoxins that are held for use during public health emergencies.
FDA Commissioner Scott Gottlieb said in a statement, "This is the first product to be awarded a Material Threat Medical Countermeasure priority review voucher. Today’s action reflects the FDA’s commitment to ensuring that the US is prepared for any public health emergency with timely, safe and effective medical products.”
Wider than the US, it is expected that the treatment will also be picked up across the globe, after a BARDA spokesperson had previously spoken to us of interest in its development from Europe.