ZOVIRAX (ORAL) REDUCES LESION HEALING TIME IN RECURRENT GENITAL HERPES

ZOVIRAX (ORAL) REDUCES LESION HEALING TIME IN RECURRENT GENITAL HERPES, according to results of a multi-center trial published in the April 27 issue of JAMA. The double-blind, placebo-controlled study, Richard Reichman, MD, University of Vermont, et al, said, found that Zovirax (acyclovir) "shortens the duration of virus shedding and the duration of lesions in patients with" recurrent genital herpes. The study reported in JAMA is the pivotal trial submitted by Burroughs Wellcome in support of its NDA for use of oral acyclovir in genital herpes. The company filed the NDA in mid-1982. The drug is currently marketed in topical and I.V. forms. The firm has sponsored several short term (four to six months) studies of acyclovir use in prevention of recurrent outbreaks which are expected to be published in the near feature. Several longer term suppression studies, including a multi-center study, expected to last over one year, are also underway. The study was divided into two parts: part A, the abstract explains, in which "patients entered the study within 48 hours of the onset of lesions, and part B, in which the same patients self-initiated therapy as soon as possible after the onset of a recurrent episode. In both parts, patients received either acyclovir (200 mg) or placebo, five times daily for five days." Two hundred fifty patients were initially enrolled in the study, with 212 patients available for analysis in part A and 165 patients available in part B. Lesions of patients in the active drug group of part A healed in an average of 6.3 days compared to 7.4 days with placebo, the study found. In part B the results were more notable with healing time in patients receiving acyclovir averaging 5.7 days v. 7.2 days with placebo. No statistically significant difference was found between the two groups in duration of either itching or pain, although a positive trend for acyclovir was noted. Also no significant differences were seen in time to next recurrence of lesion outbreak, "suggesting that this therapy does not affect the latent state," the report states. Commenting on the study's significance the authors note that "this report established orally administered acyclovir as the first, well-documented therapeutic modality to affect both the virological and clinical course of recurrent genital herpes." Further, the reviewers note, "the prevention of new lesion formation, observed in the present study when the drug was administered early, suggests that prophylactic administration of oral acyclovir may be even more effective." In an editorial accompanying the article, William Wittington and Willard Cates Jr., MD, Centers for Disease Control, noted the potential market for prophylactic use of oral acyclovir is conservatively estimated at 1 mil. They expressed some concern that widespread use could result in development of resistant herpes strains and that toxicity effects of long-term use are unknown. The editorial asserted that the "best candidates" for therapy or prophylaxis are those "with a history of frequent recurrences." The editorial declared: "We advocate an approach that would use cautious clinical judgment. Our concerns about potential viral resistance and toxicity are theoretical at this time. Realistically, neither concern may be valid, but . . . the agent has been evaluated only in several carefully characterized patients."