FDA approves Tpoxx for smallpox.- SIGA Technologies.

The FDA has approved Tpoxx (tecovirimat), from SIGA Technologies, as the first drug with an indication for treatment of smallpox. Tpoxx's effectiveness against smallpox was established by studies conducted in animals infected with viruses that are closely related to the virus that causes smallpox, and was based on measuring survival at the end of the studies. More animals treated with Tpoxx lived compared to the animals treated with placebo. Tpoxx was approved under the FDA's Animal Rule, which allows efficacy findings from adequate and well-controlled animal studies to support an FDA approval when it is not feasible or ethical to conduct efficacy trials in humans.

The safety of Tpoxx was evaluated in 359 healthy human volunteers without a smallpox infection. The most frequently reported side effects were headache, nausea and abdominal pain. The FDA granted this application Fast Track and Priority Review designations. Tpoxx also received Orphan Drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases and a Material Threat Medical Countermeasure Priority Review Voucher, which provides additional incentives for certain medical products intended to treat or prevent harm from specific chemical, biological, radiological and nuclear threats.