Synthesis and Evaluation of Anti-HIV Activity of Mono- and Di-Substituted Phosphonamidate Conjugates of Tenofovir

The activity of nucleoside and nucleotide analogs as antiviral agents requires phosphorylation by endogenous enzymes. Phosphate-substituted analogs have low bioavailability due to the presence of ionizable negatively-charged groups. To circumvent these limitations, several prodrug approaches have been proposed. Herein, we hypothesized that the conjugation or combination of the lipophilic amide bond with nucleotide-based tenofovir (TFV) (1) could improve the anti-HIV activity. During the current study, the hydroxyl group of phosphonates in TFV was conjugated with the amino group of L-alanine, L-leucine, L-valine, and glycine amino acids and other long fatty ester hydrocarbon chains to synthesize 43 derivatives. Several classes of derivatives were synthesized. The synthesized compounds were characterized by 1H NMR, IR, UV, and mass spectrometry. In addition, several of the synthesized compounds were evaluated as racemic mixtures for anti-HIV activity in vitro in a single round infection assay using TZM-bl cells at 100 ng/mL. TFV (1) was used as a positive control and inhibited HIV infection by 35%. Among all the evaluated compounds, the disubstituted heptanolyl ester alanine phosphonamidate with naphthol oleate (69), pentanolyl ester alanine phosphonamidate with phenol oleate (62), and butanolyl ester alanine phosphonamidate with naphthol oleate (87) ester conjugates of TFV were more potent than parent drug TFV with 79.0%, 76.5%, 71.5% inhibition, respectively, at 100 ng/mL. Furthermore, two fatty acyl amide conjugates of tenofovir alafenamide (TAF) were synthesized and evaluated for comparative studies with TAF and TFV conjugates. Tetradecanoyl TAF conjugate 95 inhibited HIV infection by 99.6% at 100 ng/mL and showed comparable activity to TAF (97–99% inhibition) at 10–100 ng/mL but was more potent than TAF when compared at molar concentration

A phase I study to assess safety, pharmacokinetics, and pharmacodynamics of a vaginal insert containing tenofovir alafenamide and elvitegravir

BackgroundNew multi-purpose prevention technology (MPT) products are needed to prevent human immunodeficiency virus (HIV) and herpes simplex virus type 2 (HSV2). In this study, we evaluated a fast-dissolve insert that may be used vaginally or rectally for prevention of infection.ObjectiveTo describe the safety, acceptability, multi-compartment pharmacokinetics (PK), and in vitro modeled pharmacodynamics (PD) after a single vaginal dose of an insert containing tenofovir alafenamide (TAF) and elvitegravir (EVG) in healthy women.MethodsThis was a Phase I, open-label, study. Women (n=16) applied one TAF (20mg)/EVG (16mg) vaginal insert and were randomized (1:1) to sample collection time groups for up to 7 days post dosing. Safety was assessed by treatment-emergent adverse events (TEAEs). EVG, TAF and tenofovir (TFV) concentrations were measured in plasma, vaginal fluid and tissue, and TFV-diphosphate (TFV-DP) concentration in vaginal tissue. PD was modeled in vitro by quantifying the change in inhibitory activity of vaginal fluid and vaginal tissue against HIV and HSV2 from baseline to after treatment. Acceptability data was collected by a quantitative survey at baseline and post treatment.ResultsThe TAF/EVG insert was safe, with all TEAEs graded as mild, and acceptable to participants. Systemic plasma exposure was low, consistent with topical delivery, while high mucosal levels were detected, with median TFV vaginal fluid concentrations exceeding 200,000 ng/mL and 1,000 ng/mL for up to 24 hours and 7 days post dosing, respectively. All participants had vaginal tissue EVG concentrations of > 1 ng/mg at 4 and 24 hours post dosing. The majority had tissue TFV-DP concentrations exceeding 1000 fmol/mg by 24 – 72 hours post dosing. Vaginal fluid inhibition of HIV-1 and HSV-2 in vitro significantly increased from baseline and was similarly high at 4 and 24 hours post dosing. Consistent with high tissue TFV-DP concentrations, p24 HIV antigen production from ectocervical tissues infected ex vivo with HIV-1 significantly decreased from baseline at 4 hours post dosing. HSV-2 production from tissue also decreased post treatment.ConclusionsA single dose of TAF/EVG inserts met PK benchmarks, with PK data supporting an extended window of high mucosal protection. PD modeling supports mucosal protection against both HIV-1 and HSV-2. The inserts were safe and highly acceptable.Clinical trial registrationClinicalTrials.gov, identifier NCT03762772

Entomological aspects and the role of human behaviour in malaria transmission in a highland region of the Republic of Yemen

© 2016 Al-Eryani et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article

Randomized controlled phase IIa clinical trial of safety, pharmacokinetics and pharmacodynamics of tenofovir and tenofovir plus levonorgestrel releasing intravaginal rings used by women in Kenya

IntroductionGlobally, many young women face the overlapping burden of HIV infection and unintended pregnancy. Protection against both may benefit from safe and effective multipurpose prevention technologies.MethodsHealthy women ages 18–34 years, not pregnant, seronegative for HIV and hepatitis B surface antigen, not using hormonal contraception, and at low risk for HIV were randomized 2:2:1 to continuous use of a tenofovir/levonorgestrel (TFV/LNG), TFV, or placebo intravaginal ring (IVR). In addition to assessing genital and systemic safety, we determined TFV concentrations in plasma and cervicovaginal fluid (CVF) and LNG levels in serum using tandem liquid chromatography-mass spectrometry. We further evaluated TFV pharmacodynamics (PD) through ex vivo CVF activity against both human immunodeficiency virus (HIV)-1 and herpes simplex virus (HSV)-2, and LNG PD using cervical mucus quality markers and serum progesterone for ovulation inhibition.ResultsAmong 312 women screened, 27 were randomized to use one of the following IVRs: TFV/LNG (n = 11); TFV-only (n = 11); or placebo (n = 5). Most screening failures were due to vaginal infections. The median days of IVR use was 68 [interquartile range (IQR), 36–90]. Adverse events (AEs) were distributed similarly among the three arms. There were two non-product related AEs graded >2. No visible genital lesions were observed. Steady state geometric mean amount (ssGMA) of vaginal TFV was comparable in the TFV/LNG and TFV IVR groups, 43,988 ng/swab (95% CI, 31,232, 61,954) and 30337 ng/swab (95% CI, 18,152, 50,702), respectively. Plasma TFV steady state geometric mean concentration (ssGMC) was <10 ng/ml for both TFV IVRs. In vitro, CVF anti-HIV-1 activity showed increased HIV inhibition over baseline following TFV-eluting IVR use, from a median of 7.1% to 84.4% in TFV/LNG, 15.0% to 89.5% in TFV-only, and −27.1% to −20.1% in placebo participants. Similarly, anti-HSV-2 activity in CVF increased >50 fold after use of TFV-containing IVRs. LNG serum ssGMC was 241 pg/ml (95% CI 185, 314) with rapid rise after TFV/LNG IVR insertion and decline 24-hours post-removal (586 pg/ml [95% CI 473, 726] and 87 pg/ml [95% CI 64, 119], respectively).ConclusionTFV/LNG and TFV-only IVRs were safe and well tolerated among Kenyan women. Pharmacokinetics and markers of protection against HIV-1, HSV-2, and unintended pregnancy suggest the potential for clinical efficacy of the multipurpose TFV/LNG IVR.Clinical Trial RegistrationNCT03762382 [https://clinicaltrials.gov/ct2/show/NCT03762382

Repeated vaginal administration of MZC and CG reduce <i>ex vivo</i> infection of the vaginal mucosa.

<p>Depo-treated macaques were administered daily original or modified MZC vs. CG intravaginally for 2 wks. Vaginal biopsies were collected at the beginning of the study (baseline) and 24 h after the last gel application as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108109#pone-0108109-g001" target="_blank">Fig 1</a>. Cervical biopsies were taken only from macaques treated with modified gels. Explants (3–6 vaginal and 2–5 cervical) were challenged with 10⁵ TCID₅₀ SHIV-RT/explant in the presence of IL-2. After ∼18 h incubation, tissues were washed and cultured for 14d in the presence of IL-2. Shown are log₁₀-transformed p27 SOFT and CUM analyses (Mean±SEM). Each symbol indicates an individual animal.</p

MIV-150 containing gels inhibit SHIV-RT infection in macaque vaginal explants up to 4d post gel exposure.

<p>Explants were challenged with SHIV-RT 24 h or 4d after exposure to diluted modified gels and cultured for 14d as described in Fig. 3. Shown are log₁₀-transformed p27 SOFT and CUM analyses (Mean±SEM) (d3-14 of culture). Summaries of n = 6–16 (24 h post gel exposure) and n = 3–6 (4d post gel exposure) experiments are shown. The LLOQ of the assay are denoted for both SOFT (solid line) and CUM (dotted line).</p

Unformulated MIV-150 inhibits SHIV-RT infection in macaque vaginal explants.

<p>PHA/IL-2 stimulated explants were challenged with SHIV-RT (10⁴ TCID₅₀/explant; 2–4 explants/condition) 24 h after ∼18 h exposure to unformulated MIV-150 (1.6 or 0.16 µM), ZA (0.466 mM or 0.0466 mM), or a combination of both vs. untreated control (Medium) (A, B). After challenge, the tissues were washed and cultured for 14d in the presence of IL-2. Shown are log₁₀-transformed p27 SOFT and CUM analyses (Mean±SEM) (d3-14 of culture). Summaries of n = 3–11 experiments are shown. The LLOQ of the assay are denoted for both SOFT (solid line) and CUM (dotted line).</p