The Food and Drug Administration has approved the first national trial of a drug to treat West Nile virus, which is quickly spreading west and has infected more than 250 people in a dozen states.
The agency cleared the way Monday for Dr. James Rahal of the New York Hospital Queens to see whether interferon can lessen the symptoms and duration of the illness in infected patients. Transmitted to humans by mosquito bites, West Nile virus can cause fever, body aches, brain swelling, coma, paralysis or death.
Tests have shown interferon to be effective in lessening the symptoms and length of hepatitis. It has also proven effective against St. Louis encephalitis, a virus similar to West Nile. There is no known treatment for West Nile virus.
Rahal first tried using interferon during the West Nile outbreaks in New York, and was asked to expand his initial trial to Louisiana during last year's St. Louis encephalitis outbreak, when anyone diagnosed with the disease was allowed to choose whether to get the treatment. He has refused to discuss his results, except to say they looked promising.
Rahal said Wednesday that he treated 15 Louisiana patients with the drug to make sure it was safe for those with West Nile.
He said the results were promising enough to get the Food and Drug Administration to approve the new trial.
"Encouraging," he said. "Not convincing, but encouraging."
Sold by Schering-Plough as Intron A, the drug is a hepatitis treatment which has been shown by lab tests to be effective against West Nile virus.
Patients across the country can enroll, but the trial most likely will focus on Louisiana and Mississippi, where 10 West Nile deaths have been confirmed this year.
Rahal said the trial studies 40 hospitalized people, aged 50 and over, chosen at random. Younger patients would be enrolled only if they are diagnosed with encephalitis, or swelling of the brain. Outpatients are not eligible.
The study will target patients whose virus is still in the blood, where it circulates before entering the brain, Rahal said. Therefore, patients must begin treatment within the first four days of being admitted.
"Once damage has occurred in the brain, it's not likely to be reversible, at least not by a drug," Rahal said. "What we want to do is increase the body's defense against the virus, and decrease the amount of virus that ultimately enters the brain or the nervous system."
The protocol calls for two weeks of interferon, whose side effects include a decrease in the white blood count and inflammation of the liver both reversible once the drug is stopped. Rahal said long-term use could cause depression, confusion and fatigue.
In a randomized and controlled trial, half the patients will receive the drug and the other half will receive basic care without it. Patients must agree in advance to allow that decision to be made for them.
Meanwhile, a third Mississippi resident died Tuesday as a result of contracting West Nile encephalitis. Officials would not release the age or gender of the victim. It brings the total number of deaths from West Nile this summer to more than 12.
A Kentucky man who was hospitalized with West Nile also died this week, Kentucky health authorities said Tuesday. It was the state's first confirmed case of the disease in a human.
Lab tests suggest that Missouri and Texas also may have suffered their first deaths from the virus.
West Nile first appeared in the United States in 1999, when seven people infected with it in New York died. Nationwide, the CDC has reported 12 U.S. deaths this year from West Nile, eight of them in Louisiana. As of Tuesday, 253 human cases of the virus had been reported to the CDC this year in 11 states and the District of Columbia.
It first appeared this year on the East Coast, but quickly spread west. This week, officials in Missouri, Kentucky and Texas said they were investigating three deaths suspected of being caused by the virus.