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Johns Hopkins Wins Multimillion-Dollar Grant to Lead Development of Anti-HIV Enema - 10/08/2014

Johns Hopkins Wins Multimillion-Dollar Grant to Lead Development of Anti-HIV Enema

Release Date: October 8, 2014

The National Institutes of Health have awarded $21 million to researchers at the Johns Hopkins University School of Medicine and seven other institutions to develop an antimicrobial solution that prevents HIV infection following anal intercourse. Johns Hopkins is the principal site for the research trials.

The solution will be delivered as a single-dose enema, or rectal douche, that contains either the anti-HIV drug tenofovir or a tenofovir derivative and provides a week’s worth of protection. Tenofovir is an antiviral medication that works by blocking a critical HIV enzyme and halts viral replication.

This pre-emptive treatment would be particularly useful for couples of mixed HIV status, i.e., one HIV-positive and one HIV-negative partner, who engage in unprotected anal intercourse. A daily tenofovir pill taken as prevention — an approach known as pre-exposure prophylaxis — is highly effective in preventing HIV transmission. However, adherence to the daily regimen is challenging, ranging between 25 and 90 percent, which has forced investigators to seek new strategies that reduce infection risk. An alternative drug formulation and delivery system is one such approach.

 “An antimicrobial enema solution goes straight to the Achilles’ heel of current HIV prevention — poor adherence to daily oral pills for pre-exposure prophylaxis,” says principal investigator Craig W. Hendrix, M.D., professor of medicine at the Johns Hopkins University School of Medicine.

 The beauty of this approach, Hendrix says, is that it capitalizes on pre-existing behaviors already common among many men who have sex with men — the use of rectal douche, prior to intercourse. Research shows that between two-thirds and three-quarters of men who have sex with men report regular use of enema prior to intercourse.

In their upcoming trials, the investigators will test different concentrations of tenofovir to determine the most effective solution strength. In addition, they will measure how much of the drug is absorbed and whether it effectively blocks HIV replication in colon cells exposed to the virus.

Other Johns Hopkins investigators involved in the research include Rahul Bakshi, Namandjé Bumpus, Brian Caffo, Richard Cone, Laura Ensign, Edward Fuchs, Justin Hanes and Mark Marzinke.

Other participating institutions include the University of California, Los Angeles; Duke University; the University of Pittsburgh; Emory University; Columbia University; Mercer University and CONRAD, an organization dedicated to improving reproductive health worldwide.