Microbicides for the prevention of HIV infection in women: an overview of recent trials.

Purpose Of Review: As the HIV/AIDS pandemic continues, the development of new prevention technologies is urgently needed. Microbicides, products applied to genital mucosal surfaces, are being developed to reduce the transmission of HIV during sexual intercourse. Microbicides have been designed to inhibit HIV from the time the virus enters the genital tract to any of the multiple steps in local virus replication.

Recent Findings: Preclinical research and development of microbicides has led to the advancement of many candidates into human clinical trials. This research has shown that cervicovaginal irritation is an important safety concern and needs to be evaluated carefully and early. New approaches to measuring local irritation are currently under investigation.

Summary: Five broad-spectrum microbicides are now being tested in large-scale effectiveness trials to measure their effects on the reduction of HIV incidence. Next-generation candidates, based on highly active antiretroviral drugs, are currently undergoing safety studies. This paper reviews the findings from trials of these products and discusses several challenges that are encountered in the clinical development of microbicides. Although complex and resource intensive, the successful completion of ongoing studies and the initiation of efficacy trials of next-generation candidates are critical to the successful development of a microbicide.