LOS ANGELES, July 15 (Xinhua) -- The U.S. Food and Drug Administration (FDA) has approved the new drug tecovirimat to treat smallpox, the first drug against the deadly disease since a huge vaccination campaign over three decades ago.
Though the World Health Organization has declared smallpox, a contagious and sometimes fatal disease, eradicated in 1980, "there have been longstanding concerns that smallpox could be used as a bioweapon," therefore tecovirimat (TPOXX) was developed, the agency said in a news release dated on Friday.
"To address the risk of bioterrorism, Congress has taken steps to enable the development and approval of countermeasures to thwart pathogens that could be employed as weapons," said FDA Commissioner Scott Gottlieb.
The approval "provides an important milestone in these efforts. This new treatment affords us an additional option should smallpox ever be used as a bioweapon," said Gottlieb.
The FDA granted approval of TPOXX to SIGA Technologies Inc. The new drug was developed in conjunction with the U.S. Department of Health and Human Services' Biomedical Advanced Research and Development Authority(BARDA).
The effectiveness of the new drug 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 placebos, according to the FDA.
The safety of TPOXX was evaluated in 359 healthy human volunteers without a smallpox infection. The most frequently reported side effects were headaches, nausea and abdominal pain.
Prior to its eradication in 1980, variola virus, the virus that causes smallpox, was mainly spread by direct contact between people.
Its symptoms typically began 10 to 14 days after infection and included fever, exhaustion, headache and backache. A rash initially consisting of small, pink bumps progressed to pus-filled sores before finally crusting over and scarring.
Complications of smallpox could include encephalitis (inflammation of the brain), corneal ulcerations (open sores on the clear, front surface of the eye) and blindness.
