Data from the studies support the efficacy and favorable safety profile of Tpoxx, an oral formulation of tecovirimat.
“Smallpox is both highly contagious and highly lethal and there is growing concern that smallpox could be used as a potential bioweapon,” CEO Phil Gomez said in prepared remarks. “A smallpox bioterror attack could be especially damaging because the majority of today’s population is not immune to the virus, as routine vaccination ended in the 1970s. Rapid spread from person-to-person can occur through speaking, breathing or touching, and smallpox also can be transmitted by direct contact with infected fluids and contaminated objects. These factors underscore the need for an effective smallpox antiviral therapy, and we believe that Tpoxx can address this need.”
Researchers assessed the efficacy of Tpoxx in non-human primate and rabbit models of smallpox. The treatment was also evaluated in a placebo-controlled human pharmacokinetic and safety study that enrolled 449 adult volunteers.
“The human safety and animal efficacy data reported in the New England Journal of Medicine are a large part of the Tpoxx new drug application and support the use of this novel antiviral agent,” Dennis Hruby, senior author and chief scientist at SIGA, added. “The absence of drug-related serious adverse events in the human safety trial coupled with a high survival rate in Tpoxx-treated non-human primates receiving a lethal challenge dose of monkeypox virus establish a compelling risk-benefit profile for Tpoxx in the treatment of smallpox.”
Siga filed a new drug application for Tpoxx with the FDA in December. Earlier this year, the FDA’s antimicrobial drugs advisory committee voted unanimously that the benefits of Tpoxx outweigh its risks.
The FDA is slated to make a decision whether or not to approve oral Tpoxx by August 8. SIGA shares were trading at $6.26 apiece in mid-afternoon activity today, up +3.7%.