Table 5.
Studies of pre-exposure prophylaxis (PrEP) in women at risk of HIV acquisition
| Trial | Study design | Proportion of women | Intervention | Findings | Adherence |
|---|---|---|---|---|---|
| Partners PrEP [70] | Double-blind, placebo-controlled RCT
4758 HIV-serodiscordant couples in Uganda and Kenya; sero-positive partner not on cART 97–98% couples married |
Woman was the HIV-negative partner in 52% of couples | Daily oral TDF or daily oral TDF/FTC or placebo | Overall efficacy was 67% for TDF and 75% for TDF/FTC
In women, overall efficacy 71% for TDF and 66% for TDF/FTC; in men, overall efficacy 63% for TDF and 84% for TDF/FTC; no difference in efficacy between men and women |
Detectable plasma tenofovir levels in 82%; PrEP associated with 90% risk reduction in this subgroup |
| TDF2 [71] | Phase II, double-blind, placebo-controlled trial
1219 heterosexual, HIV-negative men and women in Botswana 87.5–90% between 21–29 years 94% single |
45.7% | Daily oral TDF/FTC vs placebo | HIV incidence 1.2 per 100 person-years in TDF/FTC group compared to 3.1 per 100 person-years in placebo group (overall efficacy 62.2%)
No difference in efficacy between men and women |
|
| Bangkok Tenofovir Study [72] | 2413 injection drug users in Thailand | 20% | Daily oral TDF vs
daily oral placebo |
Overall efficacy 48.9% for reducing HIV acquisition; in women, overall efficacy was 78.6% vs 37.6% in men
Efficacy 73.5% in those with detectable plasma tenofovir levels. |
Higher adherence in those >40 years and in women |
| FEM-PrEP [73] | Phase III, double-blind, placebo-controlled trial
2120 heterosexual women in South Africa, Kenya, Tanzania Mean age 24.2 years 30.0–31.8% married |
100% | Daily oral TDF/FTC vs placebo | HIV incidence 4.7 per 100 person-years in TDF/FTC group vs. 5.0 per 100 person-years in placebo group (no reduction in HIV acquisition risk, HR 0.94) | Adherence was 95% by self-report; 88% by pill count; <40% had detectable plasma tenofovir levels |
| VOICE [74] | Phase IIb, double-blind, placebo-controlled trial
5029 heterosexual women in Eastern and Southern Africa Mean age 25.3 years Majority of women unmarried |
100% | Daily oral TDF or daily oral TDF/FTC or daily oral placebo or daily 1% vaginal tenofovir gel or daily placebo vaginal gel | No difference in HIV acquisition risk between any of the five groups | Adherence 90% by self-report, 86% by returned pills and ≤30% by drug levels
Having detectable tenofovir plasma levels associated with being >25 years (OR 1.62) or married (OR 2.25) |
| CAPRISA [75] | Double-blind, placebo-controlled trial
889 heterosexual women in South Africa Mean age 24.2 years 87.6–88.5% had a steady partner 5.4–5.8% married |
100% | Daily 1% tenofovir vaginal gel or daily vaginal placebo gel | HIV incidence 5.6 per 100 person-years in tenofovir gel group vs 9.1 per 100 person-years in placebo group (39% overall efficacy) | Efficacy 54% when adherence >80%; reduced to 38% when adherence 50–80% and 28% when adherence <50% |
| FACTS 001 [76] | Phase III, double-blind, placebo-controlled trial
2029 heterosexual women in South Africa Mean age 23 years 88% unmarried |
100% | Peri-coital 1% tenofovir vaginal gel or peri-coital placebo vaginal gel | No reduction in HIV acquisition risk between groups (IRR 1.0, 95% CI 0.7–1.4) | Only 20% reported using the product |
| ASPIRE [77] | Phase III, double-blind, placebo-controlled trial
2629 heterosexual women in Africa Median age 26 years 41% married 99.5% with steady partner |
100% | Dapivirine impregnated vaginal ring (change every 4 weeks) vs placebo vaginal ring | HIV incidence 3.3 per 100 person-years in DPV group vs 4.5 per 100 person-years in placebo group (overall efficacy 27%)
When excluded 2 sites with lower adherence, overall efficacy improved to 37% Efficacy 61% in women ≥25 years vs 10% in women <25 years |
Overall adherence 82% by plasma DPV levels |
| RING [78] | Phase III, double-blind, placebo-controlled trial
1959 heterosexual women in South Africa and Uganda Median age 25 years 90% unmarried |
100% | Dapivirine impregnated vaginal ring (change every 4 weeks) vs placebo vaginal ring | HIV incidence 4.08 per 100 person-years in DPV group vs 6.10 per 100 person-years in placebo (overall efficacy 30.7%, P=0.04); efficacy improved to 37.5% in subgroup of women ≥21 years of age |
PrEP: pre-exposure prophylaxis; cART: combination antiretroviral therapy; TDF: tenofovir disoproxil fumarate; FTC: emtricitabine; HR: hazard ratio; OR: odds ratio; DPV: dapivirine; vs: versus; IRR: incidence risk ratio; CI: confidence interval.