Results from PrEP Efficacy Trials
Clinical trials have demonstrated the safety and efficacy of pre-exposure prophylaxis (PrEP) for preventing HIV
| Trial (Reference) | Population | Location | PrEP Regimen |
Efficacy | PrEP Adherence |
Notes |
|---|---|---|---|---|---|---|
|
iPrEX (Grant RM; N Engl J Med 2010;363:2587-2599)
Phase III trial that evaluated the safety and efficacy of once-daily oral TDF/FTC to prevent HIV infection in men who have sex with men and transgender women who have sex with men. For more information: www.avac.org/trial/iprex |
2,499 men and transgender women who have sex with men | USA, Peru, Ecuador, Brazil, Thailand, South Africa | TDF/FTC | 44% reduction in HIV incidence compared to placebo | 51% | In participants with >90% adherence, efficacy was 77% |
|
FEM-PrEP (Van Damme L;. N Engl J Med 2012;367:411-422)
Phase III trial that evaluated the safety and effectiveness of once-daily oral TDF/FTC for HIV prevention in women. For more information: www.avac.org/trial/fem-prep
|
2,120 women | Kenya, South Africa, Tanzania | TDF/FTC | N/A | 21–37% | Adherence was too low to evaluate efficacy |
|
TDF-2 (Thigpen MC; N Engl J Med 2012;367:423-434)
Phase II/III trial that evaluated the safety of once-daily oral TDF/FTC in heterosexual men and women. For more information: www.avac.org/trial/tdf2 |
1,219 women and men | Botswana | TDF/FTC | 62% reduction in HIV incidence compared to placebo | 84% | Efficacy was 78% when restricting the analyses to seroconverters within 30 days of last dose |
|
Partners PrEP (Baeten JM;. N Engl J Med 2012;367:399-410)
Phase III trial that evaluated the safety and efficacy of two different strategies to prevent HIV transmission in HIV-serodiscordant couples: once-daily oral TDF and once-daily oral TDF/FTC. For more information: www.avac.org/trial/partners-prep |
4,758 serodiscordant, heterosexual couples | Kenya, Uganda | TDF/FTC | 75% reduction in HIV incidence compared to placebo | 82% | No significant differences in efficacy by gender |
| TDF | 67% reduction in HIV incidence compared to placebo | |||||
|
VOICE (Marrazzo JM;. N Engl J Med 2015;372:509-518)
Phase IIb trial that evaluated the safety and effectiveness of three different strategies to prevent HIV in women: once-daily oral TDF, oral TDF/FTC, and vaginal tenofovir gel. For more information: www.avac.org/trial/mtn-003-voice |
5,029 women | Uganda, South Africa, Zimbabwe | TDF/FTC | N/A | 29% | Inefficacy was attributed to poor adherence |
| TDF | N/A | 30% | ||||
|
PROUD (McCormack S; Lancet 2016;387:53-60)
Phase IV trial that evaluated the efficacy and uptake of once-daily oral TDF/FTC among men who have sex with men. For more information: www.avac.org/trial/mtn-003-voice |
544 men who have sex with men | UK | TDF/FTC | 86% reduction in HIV incidence among immediate PrEP users compared to deferred PrEP users | ~100% | Trial stopped due to early demonstration of efficacy |
|
Bangkok Tenofovir Study (Choopanya K; Lancet 2013;381:2083-90)
Phase II/III trial to assess the safety and efficacy of daily TDF to prevent HIV among people who inject drugs. For more information: www.avac.org/trial/cdc-4370-bangkok-tenofovir-study |
2,413 people who inject drugs | Thailand | TDF | 49% reduction in HIV incidence compared to placebo | 61-71% | Among those with detectable TDF, efficacy was 70% |
|
DISCOVER (Mayer K; Lancet 2020; 396(10246):239-254) TAF/FTC vs TDF/FTC
Phase III trial to compare the efficacy of Discovy daily tenofovir alafenamide/emtricitabine (TAF/FTC) and tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) among men who have sex with men and transgender women who have sex with men. For more information:www.avac.org/trial/discover |
5,387 men and transgender women who have sex with men | Austria, Denmark, France, Germany, Ireland, Italy, Netherlands, Spain, UK, Canada and USA | TDF/FTC | 99.4% remained HIV negative | 84–96% |
|
| TAF/FTC | 99.7% remained HIV negative | |||||
|
Long-acting PrEP (Landovitz R; N Engl J Med; 2021 385:595-608)
Phase IIb/III trial to evaluate the safety and efficacy of injectable drug cabotegravir (CAB-LA) among men who have sex with men and transgender women who have sex with men. For more information: www.avac.org/trial/hptn-083 |
4,566 men and transgender women who have sex with men | Argentina, Brazil, Peru, South Africa, Thailand, the U.S., and Vietnam | CAB-LA | 99.6% remained HIV negative | - |
|
| TDF/FTC | 98.8% remained HIV negative | |||||
|
Reference: PrEP Efficacy Trial Results: Pacific AIDS Education & Training Center (Pacific AETC);
[Available from: http://paetc.org/wp-content/uploads/2018/02/PAETC_PrEPEfficacy.pdf.] |
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