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Abstract: Introduction: Fast‐dissolving vaginal film formulations release antiretroviral drugs directly into vaginal fluid and may be as efficient at drug delivery yet more acceptable to women than gels. In this Phase 1 vaginal film study, the safety, acceptability, pharmacokinetics and pharmacodynamics of two doses of tenofovir (TFV) film and TFV 1% gel were compared to corresponding placebo formulations. Methods: Seventy‐eight healthy HIV negative women were randomized to self‐insert daily vaginal film (10 mg TFV, 40 mg TFV or placebo) or 4 mL of vaginal gel (TFV 1% [40 mg] or placebo) for seven days. Grade 2 and higher adverse events (AEs) related to study product were compared across study arms using Fisher's exact test. Plasma TFV concentrations were measured before and 2 hours after last product use. Paired cervical and vaginal tissue biopsies obtained 2 hours after the last dose were measured to determine tenofovir diphosphate (TFV‐DP) concentrations and exposed to HIV in an ex vivo challenge assay. Acceptability was assessed through questionnaire. Results: There was only one grade 2 or higher related AE, the primary endpoint; it occurred in the placebo gel arm. AEs occurred in 90% of participants; the majority (91%) were grade 1. AEs were similar across study arms. TFV concentrations in plasma and TFV‐DP concentrations in cervical and vaginal tissues were comparable between 40 mg TFV film and the TFV gel groups. There was a significant relationship between reduced viral replication and TFV‐DP concentrations in cervical tissues. Film users were less likely to report product leakage than gel users (66% vs. 100%, p < 0.001). Conclusions: Films were safe and well tolerated. Furthermore, films delivered TFV to mucosal tissues at concentrations similar to gel and were sufficient to block HIV infection of genital tissue ex vivo. [ABSTRACT FROM AUTHOR]

Objectives: The CHARM-01 study characterized the safety, acceptability, pharmacokinetics (PK), and pharmacodynamics (PD) of three tenofovir (TFV) gels for rectal application. The vaginal formulation (VF) gel was previously used in the CAPRISA 004 and VOICE vaginal microbicide Phase 2B trials and the RMP-02/MTN-006 Phase 1 rectal safety study. The reduced glycerin VF (RGVF) gel was used in the MTN-007 Phase 1 rectal microbicide trial and is currently being evaluated in the MTN-017 Phase 2 rectal microbicide trial. A third rectal specific formulation (RF) gel was also evaluated in the CHARM-01 study. Methods: Participants received 4 mL of the three TFV gels in a blinded, crossover design: seven daily doses of RGVF, seven daily doses of RF, and six daily doses of placebo followed by one dose of VF, in a randomized sequence. Safety, acceptability, compartmental PK, and explant PD were monitored throughout the trial. Results: All three gels were found to be safe and acceptable. RF and RGVF PK were not significantly different. Median mucosal mononuclear cell (MMC) TFV-DP trended toward higher values for RF compared to RGVF (1136 and 320 fmol/106 cells respectively). Use of each gel in vivo was associated with significant inhibition of ex vivo colorectal tissue HIV infection. There was also a significant negative correlation between the tissue levels of TFV, tissue TFV-DP, MMC TFV-DP, rectal fluid TFV, and explant HIV-1 infection. Conclusions: All three formulations were found to be safe and acceptable. However, the safety profile of the VF gel was only based on exposure to one dose whereas participants received seven doses of the RGVF and RF gels. There was a trend towards higher tissue MMC levels of TFV-DP associated with use of the RF gel. Use of all gels was associated with significant inhibition of ex vivo tissue HIV infection. Trial Registration: ClinicalTrials.gov [ABSTRACT FROM AUTHOR]

Objectives: This study was designed to assess the dose-response relationship between tissue, blood, vaginal and rectal compartment concentrations of tenofovir (TFV) and tenofovir diphosphate (TFVdp) and ex vivo rectal HIV suppression following oral tenofovir disoproxil fumarate (TDF) and rectal administration of TFV 1% vaginally-formulated gel. Design: Phase 1, randomized, two-site (US), double-blind, placebo-controlled study of sexually-abstinent males and females. Methods: Eighteen participants received a single 300 mg exposure of oral TDF and were then randomized 2∶1 to receive a single then seven-daily rectal exposures of TFV 1% gel (40 mg TFV per 4 ml gel application) or hydroxyethyl-cellulose (HEC) placebo gel. Blood and rectal biopsies were collected for pharmacokinetic TDF and TFVdp analyses and ex vivo HIV-1 challenge. Results: There was a significant fit for the TFVdp dose-response model for rectal tissue (p = 0.0004), CD4+MMC (p<0.0001), CD4−MMC (p<0.0001), and TotalMMC (p<0.0001) compartments with r2 ranging 0.36–0.64. Higher concentrations of TFVdp corresponded with lower p24, consistent with drug-mediated virus suppression. The single oral treatment failed to provide adequate compartment drug exposure to reach the EC50 of rectal tissue TFVdp predicted to be necessary to suppress HIV in rectal tissue. The EC50 for CD4+MMC was within the single topical treatment range, providing evidence that a 1% topical, vaginally-formulated TFV gel provided in-vivo doses predicted to provide for 50% efficacy in the ex vivo assay. The 7-daily topical TFV gel treatment provided TFVdp concentrations that reached EC90 biopsy efficacy for CD4−MMC, CD4+MMC and TotalMMC compartments. Conclusion: The TFVdp MMC compartment (CD4+, CD4− and Total) provided the best surrogate for biopsy infectibility and the 7-daily topical TFV gel treatment provided the strongest PK profile for HIV suppression. : ClinicalTrials.gov [ABSTRACT FROM AUTHOR]

This Phase 1, randomized, two-site (United States), double-blind, placebo-controlled study enrolled 18 sexually abstinent men and women. All received a single 300-mg dose of oral tenofovir disoproxil fumarate (TDF) and were then randomized 2∶1 to receive single and then seven daily rectal exposures of vaginally-formulated tenofovir (TFV) 1% gel or a hydroxyethyl cellulose (HEC) placebo gel. Blood, colonic biopsies and rectal and vaginal mucosal fluids were collected after the single oral TDF, the single topical TFV gel dose, and after 7 days of topical TFV gel dosing for extracellular analysis of TFV and intracellular analysis of the active metabolite tenofovir diphosphate (TFVdp) in peripheral blood mononuclear cells (PBMCs) and isolated mucosal mononuclear cells (MMC), including CD4+ and CD4- cell subsets. With a single rectal dose, TFV plasma concentrations were 24–33 fold lower and half-life was 5 h shorter compared to a single oral dose (p = 0.02). TFVdp concentrations were also undetectable in PBMCs with rectal dosing. Rectal tissue exposure to both TFV and TFVdp was 2 to 4-log10 higher after a single rectal dose compared to a single oral dose, and after 7 daily doses, TFVdp accumulated 4.5 fold in tissue. TFVdp in rectal tissue homogenate was predictive (residual standard error, RSE  = 0.47) of tissue MMC intracellular TFVdp concentration, with the CD4+ cells having a 2-fold higher TFVdp concentration than CD4- cells. TFV concentrations from rectal sponges was a modest surrogate indicator for both rectal tissue TFV and TFVdp (RSE  = 0.67, 0.66, respectively) and plasma TFV (RSE  = 0.38). TFV penetrates into the vaginal cavity after oral and rectal dosing, with rectal dosing leading to higher vaginal TFV concentrations (p<0.01). Trial Registration: ClinicalTrials.gov [ABSTRACT FROM AUTHOR]