Pharmacokinetics and Pharmacodynamics of Tenofovir Reduced-Glycerin 1% Gel in the Rectal and Vaginal Compartments in Women: A Cross-Compartmental Study With Directly Observed Dosing.

BACKGROUND: Evidence is lacking regarding whether vaginal pre-exposure prophylaxis with topical tenofovir (TFV) reduces the risk of rectal HIV acquisition. SETTING: Bronx, NY. METHODS: MTN-014 was a phase 1, cross-over, randomized sequence trial comparing the cross-compartment pharmacokinetics and pharmacodynamics of daily TFV reduced-glycerin 1% gel after 14 days each of rectal and vaginal application, with directly observed dosing and a 6-week washout period between phases. RESULTS: Fourteen HIV-uninfected women enrolled; 91% of doses were observed and 13 women completed all study procedures. TFV and TFV diphosphate (TFV-DP) were detected in most samples collected from the dosing compartment. After vaginal dosing, TFV was detected in 10/14 samples of rectal fluid (RF) (median 4.4 ng/sponge) and 1/13 rectal tissue samples (0.2 ng/mg); TFV-DP was detected in 2/13 rectal tissue samples at 59.8 and 76.5 fmol/mg. After rectal dosing, TFV was detected in 9/14 samples of vaginal fluid (median 1.1 ng/swab) and in 6/14 vaginal tissue samples (median below limit of quantification); TFV-DP was detected in 3/14 vaginal tissue samples at 17.3, 87.6, and 77.1 fmol/mg. Neither cervicovaginal lavage fluid nor RF collected 24 hours after rectal or vaginal dosing resulted in a statistically significant suppression of viral replication. CONCLUSIONS: In this study of 14 days each of vaginal and rectal application of TFV reduced-glycerin 1% gel, we found only a small degree of cross-compartment distribution of TFV in RF and vaginal fluids and no pharmacodynamic activity in ex vivo testing. Although high TFV concentrations in the dosing compartment may be protective, low cross-compartment tissue concentrations are not likely to be protective.

Risk Factors for Incidence of Sexually Transmitted Infections Among Women in a Human Immunodeficiency Virus Chemoprevention Trial: VOICE (MTN-003).

BACKGROUND: In sub-Saharan Africa, there are limited data on the incidence of sexually transmitted infections (STIs) among women, largely because routine screening for asymptomatic infection is not performed. We conducted a secondary analysis to measure STI incidence rates and determine risk factors for new STI acquisition among women enrolled in the VOICE trial. METHODS: We analyzed data from 4843 women screened for chlamydia, gonorrhoea, syphilis, and trichomonas infection at baseline, annually, at interim visits when clinically indicated and at their study termination visit. Risk reduction counseling and condoms were provided throughout the trial. RESULTS: Twenty percent of evaluable participants had one or more curable STIs at baseline. Over 5660 person-years at risk (PYAR) of observation, incidence rates were 13.8% (95% confidence interval [CI], 12.7-14.8) PYAR for chlamydia, 3.5% (95% CI, 3.0-4.1) PYAR gonorrhea, 0.1% (95% CI, 0.6-1.1) PYAR syphilis, and 6.6% (95% CI, 5.8-7.2) PYAR trichomoniasis. South African sites had the highest incidence of chlamydia. The Uganda site had the highest incidence of gonorrhoea and syphilis, and Zimbabwe the lowest incidence overall. The majority of these cases were diagnosed at a routine scheduled testing visit. In multivariate analysis, positive baseline STI, younger than 25 years, being unmarried, and some alcohol consumption were associated with acquiring a new STI. CONCLUSIONS: We observed high rates of STIs during follow up among women in the VOICE study. Women living in human immunodeficiency virus endemic countries should be screened for common STIs.