ZOVIRAX CHICKEN POX POSTMARKETING STUDY WILL ASSESS CLINICAL BENEFIT

ZOVIRAX CHICKEN POX POSTMARKETING STUDY WILL ASSESS CLINICAL BENEFIT to patients who receive the therapy more than 24 hours after developing symptoms of chicken pox. The Burroughs Wellcome antiviral drug was approved for chicken pox use on Feb. 26 based on studies in which patients were treated within 24 hours of their developing characteristic chicken pox lesions. Further investigation into the timing of administration of Zovirax was suggested by pediatrician Catherine Wilfert, MD, Duke University Medical Center, at a Nov. 12 meeting of FDA's Antiviral Drugs Advisory Committee during which Zovirax was recommended for approval. Burroughs Wellcome plans to provide information on the use of Zovirax for chicken pox directly to pediatricians and primary care physicians. The company said it will also educate consumers about the course of the disease and availability of therapies. The firm declined to elaborate on the nature of its consumer educational program. The cost of a five-day course of Zovirax therapy for chicken pox is $30-$55 (based on the manufacturer-level price for Zovirax). The product is available in 800 mg tablets, 200 mg capsules, and a banana-flavored suspension. A 473 ml bottle of the Zovirax suspension containing 200 mg/5 ml costs $61.79 to wholesalers. To make a significant dent in the estimated 3.5 mil. cases of chicken pox annually in the U.S., Burroughs Wellcome will have to convince physicians that shortening the course of the disease is worth drug treatment. As one FDA panel member said, chicken pox is a "benign rite of passage." In the subpopulation of adult cases, Zovirax is expected to be used more readily. Adult cases constitute fewer than 2% of the 3.5 mil. cases seen annually. Burroughs Wellcome was able to gain approval for Zovirax ahead of Merck's Varivax varicella vaccine. An advisory committee recommended approval for Varivax more than two years ago. However, last November, Merck predicted at least another year before approval.