Antiviral With New Purpose

Can you develop a drug for a disease that no longer exists? That’s what scientists at SIGA Technologies wondered two decades ago, when they set out to make a smallpox therapy in case the eradicated virus was ever used as a bioweapon. U.S. regulators approved the resulting oral antiviral, TPOXX (tecovirimat), largely based on animal data. Now it has become a crucial treatment for people infected with the monkeypox virus, a smallpox relative that caused a significant outbreak this year. The European Medicines Agency authorized its use for that virus in January; the FDA approved a new intravenous formulation in May. But prescribing TPOXX remains a byzantine process in the U.S., since the drug is only experimentally allowed for use against monkeypox; SIGA’s Chief Scientific Officer Dennis Hruby says the company is working toward full licensure.

Write to Jamie Ducharme at jamie.ducharme@time.com.