A topically applied microbicide gel containing a potent anti-HIV drug has been found to significantly reduce infection when applied to rectal tissue that was subsequently exposed to HIV in the laboratory, according to a new study by the UCLA AIDS Institute. The gel was also found to be safe and acceptable to users.
The first-ever phase 1 clinical trial of the rectal HIV-prevention drug known as UC781, a non-nucleoside reverse transcriptase inhibitor, is described in the current edition of the online journalPLoS ONE.
The trial represents the first use of this novel approach to obtain early insights into the drug's potential to prevent real-life infections during sexual exposure. In addition, it represents an important contribution to efforts aimed at strategically preventing HIV transmission during receptive anal intercourse.
While anal-receptive intercourse is known to be the main route for new HIV infections in men who have sex with men, far more women than men worldwide practice anal intercourse. The risk of HIV infection, per sex act, is anywhere from 20 to 2,000 times greater with receptive anal sex than receptive vaginal sex — particularly if there are other infections present, such as herpes, gonorrhea or chlamydia, according to the study's lead author, Dr. Peter Anton, a professor of medicine in the division of digestive diseases at the David Geffen School of Medicine at UCLA.
Dr. Nancy Padian 10-year study on HIV transmission
