FDA Approves Testing of West Nile Virus Drug

The Food and Drug Administration gave the go-ahead this week for the first national trial of a drug to treat the West Nile virus, a mosquito-transmitted disease that has killed 13 people this year.

The trial, announced by Dr. James Rahal at a news conference Wednesday in New York, will study whether the drug alpha- interferon lessens the symptoms and duration of the illness.

The West Nile virus has spread rapidly since 1999, when the first cases in the United States were confirmed in New York. It has been diagnosed as far west as Texas in humans and Wyoming in animals, and experts warn that it is only a matter of time before it appears on the West Coast. This year, 269 cases have been reported to the Centers for Disease Control and Prevention.

Individuals infected with West Nile may suffer problems ranging from mild flu-like symptoms to paralysis, brain swelling and death.

The study will examine whether interferon, which has shown promise in treating the similar St. Louis virus, can stop the progression of West Nile. There currently are no approved treatments for either virus. The drug is sold by Schering-Plough Corp. under the trade name Intron A.

“Right now, patients are treated with supportive care--intravenous fluids maintaining vital organ function. If a patient is unable to breathe, they intubate them,” Rahal said. “We’re hoping that the drug would prevent people from progressing to that state.”

Rahal, director of infectious diseases at New York Hospital Queens and a professor of medicine at Cornell University, used the drug during the initial outbreak of West Nile in the United States. It was used again last year in Monroe, La., during an outbreak of the St. Louis virus, which is also spread by mosquitoes.

In Louisiana, 15 people were treated with Intron A, and their responses compared with those of earlier patients who had not received the drug. Rahal said the results, which he plans to publish, were “very promising” but conceded that the study did not follow standard scientific protocols.

The new study, which Rahal hopes to begin as soon as possible, will enroll 40 patients over age 50 who are hospitalized with West Nile virus.

Those who enroll will be required to sign an informed consent form because the drug is currently approved only for the treatment of hepatitis C and genital warts.

Rahal said the study is looking for patients who are in the early stages of illness and who have been hospitalized for no more than four days. Outpatients do not qualify. Younger patients may be enrolled if they are diagnosed with encephalitis, a potentially fatal brain swelling that can be caused by the virus.

Interferon is a compound produced by the body as a first-line defense against viral infection. It has also been shown to stimulate the immune system. Reported side effects, which include fever, chills and fatigue, are usually mild.

The age requirement was set because older people are considered at greatest risk of developing encephalitis, the most serious form of the disease. If enrolled in the study, a patient would be randomly assigned to receive either a placebo or the drug.

In previous outbreaks, from 10% to 30% of patients over age 50 have died. The informed consent form, however, points out that about 80% of patients infected with West Nile or St. Louis virus recover after receiving only general support such as intravenous fluids.

While concern has run high in 13 states and the District of Columbia, where human cases have been diagnosed, health officials have cautioned that higher numbers of Americans will die of more common diseases, such as influenza, this year.

Still, people have been warned to take precautions to avoid mosquito bites and to alert local health officials to dead birds. Birds carry the virus and can transfer it to mosquitoes.

Additional information about the study is available at: www.nyhq.org/posting/rahal.html.