Pre- vs Postexposure Prophylaxis HIV Postexposure prophylaxis 0 hr 36 hr 72 hr1 mos3 mos5 mos HIV
Pre- vs Postexposure Prophylaxis HIV Pre-exposure prophylaxis 0 hr 36 hr 72 hr1 mos3 mos5 mos HIV
Why Chemoprophylaxis? Post- and Pre-Exposure Prophylaxis: PEP and PrEP for Seronegatives People whose partners: – May have acute infection, – Have unknown serostatus, – Are not treated, or not treated effectively. May inspire an active approach to prevention: – Reduced stigma by breaking the drug-disease link, – Options for couples. No interference with sexual practices.
The reality: PrEP efficacy trial results, March 2012 StudyPopulationNResults CAPRISA 004 South Africa Women88939% efficacy vaginal TFV gel iPrEx Brazil, Ecuador, Peru, South Africa, Thailand, US MSM249944% efficacy FTC/TDF TDF2 Study Botswana Young men and women 120062% efficacy FTC/TDF Partners PrEP Study Kenya, Uganda Heterosexual couples 4758 67% efficacy TDF 75% efficacy FTC/TDF FEM-PrEP Kenya, S Africa, Tanzania Women1950FTC/TDF = futility VOICE South Africa, Uganda, Zimbabwe Women5029 TDF = futility Vaginal TFV gel = futility FTC/TDF ongoing Bangkok Tenofovir Study Thailand IDUs2400TDF ongoing FACTS001 South Africa Women2200TFV gel enrolling Baeten et al, CROI 2012
Prophylactic Activity of Oral FTC/TDF ”When Detected” TrailPopulationEfficacySeronegative Drug Exposure Risk Reduction If Drug Detected iPrExMSM 42%44%92% Partners PrEP Men and Women 75%81%90% FEMPREPWomen 18%*26%** *Pre-specified “as treated” analysis through visit of last dose. ** Drug detected in seronegatives at both of 2 timepoints. Anderson CROI 2012; Baeten CROI 2012; Donnell CROI 2012; Van Damme CROI 2012;
Summary of Evidence of No or Low Drug Exposure Among Active Arm Seroconverters: iPrEx, Partners PrEP No suppression of plasma viral RNA No selection for drug resistance No detectable drug in 91% – Low levels of drug in the others
Ways PrEP Could Enable Treatment Decreased burden on HIV treatment programs. Motivates HIV testing, – Provides benefits to people hoping they are uninfected, – Seropositives may be linked into care, – More timely identification of acute infections. Greater familiarity with antiretroviral therapy, – A diversity of providers serving a diversity of people,, – Uninfected people become aware of therapy and HIV, – May destigmatize therapy and the people who use it.