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Daily oral antiretroviral use for the prevention of HIV infection in heterosexually active young adults in Botswana: results from the TDF2 study. MC Thigpen, PM Kebaabetswe , DK Smith, TM Segolodi , FA Soud , K Chillag , LI Chirwa , M Kasonde ,
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Daily oral antiretroviral use for the prevention of HIV infection in heterosexually active young adults in Botswana: results from the TDF2 study MC Thigpen, PM Kebaabetswe, DK Smith, TM Segolodi, FA Soud, K Chillag, LI Chirwa, M Kasonde, R Mutanhaurwa, FL Henderson, S Pathak, R Gvetadze, CE Rose, LA Paxton for the TDF2 Study Team
Background Preexposure Prophylaxis Initiative (iPrEX) study among men who have sex with men Tenofovir-emtricitabine (TDF-FTC) reduced HIV transmission by 44% [95% Confidence Interval (95% CI) 15% to 63%, p=0.005] Interim data from FemPrEP study among high risk women showed no such protective effect Additional safety and efficacy data among heterosexual men and women are needed
TDF2 Methods Study Design: Double-blind placebo-controlled randomized clinical trial TDF-FTC vs. matching placebo ≥ 1200 male and female Botswana citizens Followed for ≥ 12 months Eligibility criteria: 18-39 years old HIV uninfected Sexually active within past 3 months Healthy Normal baseline laboratory tests No chronic medical conditions Not pregnant or breast feeding Willing to use hormonal contraception
TDF2 Methods (2) Study procedures: Tested for HIV infection every month Dual rapid fingerstick tests at screening Monthly oral transudate (Oraquick) thereafter Positives confirmed by additional testing EIA, Plasma viral load, ARV resistance testing Monitored for illness and side effects Lab testing at Month 1 & 2 then every 3 months Individualized HIV risk reduction and medication adherence counseling Assessed adherence using multiple measures Self-report, Pill counts, Drug levels
Baseline Characteristics among TDF2 Study Participants
Efficacy – Intention-to-Treat Analysis 9 HIV-infected in TDF-FTC group and 24 HIV-infected in placebo group Overall protective efficacy 62.6% (95% CI 21.5 to 83.4, p=0.0133)
Efficacy – Participants on Study 4 HIV-infected in TDF-FTC group and 19 HIV-infected in placebo group Overall protective efficacy 77.9% (95% CI 41.2 to 93.6, p=0.0053)
Drug Resistance • One participant with unrecognized acute wild-type HIV infection at enrollment started on TDF-FTC • All mutations emerged to high levels • K65R • M184V • Also A62V conferring cross-NRTI resistance • One participant in placebo group • K65R only in very low levels (<1%)
Safety Number (%) Participants with Clinical adverse events by treatment group
Safety (2) Number Abnormal Laboratory Values by treatment group
Conclusions • Daily TDF-FTC effective and safe for prevention of HIV infection among heterosexual men and women overall compared to placebo • Data suggests efficacy for men and women separately, but study not large enough to draw definitive conclusions by gender • Overall safety and efficacy findings consistent with Partners PrEP data
Next steps • Other planned analyses include • Efficacy among participants with varying levels of self-reported adherence • Drug level testing for efficacy and adherence • Change in bone mineral density • Trends in risk behavior over time • Open label provision of TDF-FTC for 12 months for all study participants • CDC & partners will fully review all heterosexual trial data & develop specific guidance for use among heterosexual men and women
Botswana Study Team Sandra Johnson Thomas Sukalac Daniel Abebe Evans Buliva Neo Tamuhla Joyce Kgampi Lionah Ockhuizen ThapeloRampebana Bonny Moapare BakgakiRatshaa Onkabetse Matlhaba NkumbuludziNdwapi KaboPilane KaboKagiso KeodiretsengMoloi CDC and BOTUSA Staff Debra Byrd Paula Casillas Lisa Harper Brandi Collins Vasavi Thomas Sherri Pals John T. Brooks Lisa Grohskopf Peter Kilmarx Margarett Davis Kathleen Toomey Clyde Hart Kevin Malotte Craig Hendrix Eugene Jooste Acknowledgements The TDF2 Participants U.S. National Institutes of Health Gilead for providing the study medication