Long-acting cabotegravir pharmacokinetics with and without oral lead-in for HIV PrEP.

Long-acting cabotegravir is approved for pre-exposure prophylaxis and combination HIV treatment, both initiated with optional short-term oral lead-in (OLI). We evaluated the impact of OLI on long-acting cabotegravir pharmacokinetics. Cabotegravir plasma concentrations were compared between HIV-positive participants initiating injections with (n = 278) or without (n = 110) OLI in phase III treatment study FLAIR and in HIV-negative participants using OLI (n = 263) in pivotal pre-exposure prophylaxis studies HPTN 083 and HPTN 084. Cabotegravir pharmacokinetic profiles were simulated in three populations (assigned-male-at-birth, 50%-assigned-female-at-birth, and assigned-female-at-birth) under three scenarios: first injection given (A) 1 or (B) 3 days after final OLI dose (OLI-injection gap) or (C) without OLI. The PK objective was 80% of participants achieving 4× in vitro protein-adjusted 90% maximal inhibitory concentration (PA-IC90) and 50% achieving 8× PA-IC90. Observed trough concentrations (Cτ) were similar with and without OLI (P > 0.3). With a 3-day OLI-injection gap, simulated pre-injection Cτ remained above PK objective. Approximately 1-2 weeks after the first injection, simulated PK profiles became nearly identical among all scenarios. Without OLI, it was predicted that 80% of participants achieve 4× PA-IC90 in 1.2, 1.8, and 2.8 days after the first injection in each population, respectively, and 50% achieve 8× PA-IC90 in 1.4, 2.1, and 3.8 days, respectively. Observed long-acting cabotegravir exposure was similar with or without OLI, supporting optional OLI use. Cabotegravir exposure was predicted to remain above PK objective for OLI-injection gaps of ≤3 days and rapidly achieve PK objective after first injection without OLI. Findings are consistent between assigned-male-at-birth and assigned-female-at-birth populations.This study is registered with ClinicalTrials.gov as NCT02720094.

Demographic diversity of US-based participants in GSK-sponsored interventional clinical trials.

BACKGROUND: Demographic diversity among clinical trials is required for representing the real-world populations intended for treatment and disease prevention. Moreover, genetic and environmental differences between ethnic and racial groups necessitate appropriately powered trials for relevant subgroups. We investigate the racial and ethnic demographic diversity of US-based participants in GSK-sponsored interventional trials. We also assess the evaluation of demographic diversity against US Census and epidemiologic data. METHODS: GSK-sponsored interventional phase I-IV clinical trials conducted from 2002 to 2019 across three areas were analyzed: pharmaceutical (includes therapeutic medicines except for vaccines and human immunodeficiency virus (HIV)), vaccine (includes prophylactic and therapeutic vaccines), and ViiV (includes HIV therapies). A total of 1005 global trials encompassing 460,707 global participants were identified, of which 495 had US-based sites with a total of 108,261 (23.5% of global) US participants (pharmaceutical, n = 357 trials; vaccine, n = 45 trials; and ViiV, n = 93 trials). We evaluated how GSK US-based trial recruitment compares with US Census (in line with previously published studies from other groups) and with epidemiologic data. RESULTS: GSK participant data for race and ethnicity combined across areas were generally similar to US Census levels (e.g. GSK versus census: White, 76.5% versus 76.3%; Black or African American, 15.1% versus 13.4%; Asian, 1.8% versus 5.9%; Hispanic or Latino, 14.0% versus 18.5%; Non-Hispanic White, 63.5% versus 60.1%). However, this was not the case for the individual pharmaceutical, vaccine, and ViiV data sets; least represented groups were Asian individuals for pharmaceutical and ViiV trials and American Indian or Alaskan Native individuals for vaccine trials (6.2%, 11.8%, and 11.1% of trials met/exceeded census level representation, respectively). The percentage of trials reaching/exceeding census levels also varied per trial phase for race and ethnicity. Furthermore, disparities in the percentage of trials reaching/exceeding census levels versus epidemiology-based prevalence levels have revealed opportunities to improve industry success metrics; in HIV trials, the proportion of Black or African American individuals (35.1%) exceeded census (13.4%) but not epidemiologic levels (55.3%). CONCLUSION: Further work is required to achieve demographic diversity across clinical trials. We conclude that US Census data are an inappropriate universal benchmark. A shift to epidemiology benchmarking will enable the consideration of global participants into US analyses for highly intrinsic (i.e. influenced by ancestry) diseases and more firm requirements for US-based participants into US analyses for extrinsic (i.e. influenced by location or culture) diseases. Benchmarking in line with epidemiologic data will allow us to set better trial enrollment goals, with the aim of conducting more demographically balanced, diverse, and representative clinical trials and enabling a better understanding of drug safety and efficacy per demographic group.

Emtricitabine and tenofovir alafenamide vs emtricitabine and tenofovir disoproxil fumarate for HIV pre-exposure prophylaxis (DISCOVER): primary results from a randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial.

BACKGROUND: Tenofovir alafenamide shows high antiviral efficacy and improved renal and bone safety compared with tenofovir disoproxil fumarate when used for HIV treatment. Here, we report primary results from a blinded phase 3 study evaluating the efficacy and safety of pre-exposure prophylaxis (PrEP) with emtricitabine and tenofovir alafenamide versus emtricitabine and tenofovir disoproxil fumarate for HIV prevention. METHODS: This study is an ongoing, randomised, double-blind, multicentre, active-controlled, phase 3, non-inferiority trial done at 94 community, public health, and hospital-associated clinics located in regions of Europe and North America, where there is a high incidence of HIV or prevalence of people living with HIV, or both. We enrolled adult cisgender men who have sex with men and transgender women who have sex with men, both with a high risk of acquiring HIV on the basis of their self-reported sexual behaviour in the past 12 weeks or their recent history (within 24 weeks of enrolment) of bacterial sexually transmitted infections. Participants with current or previous use of PrEP with emtricitabine and tenofovir disoproxil fumarate were not excluded. We used a computer-generated random allocation sequence to randomly assign (1:1) participants to receive either emtricitabine (200 mg) and tenofovir alafenamide (25 mg) tablets daily, with matched placebo tablets (emtricitabine and tenofovir alafenamide group), or emtricitabine (200 mg) and tenofovir disoproxil fumarate (300 mg) tablets daily, with matched placebo tablets (emtricitabine and tenofovir disoproxil fumarate group). As such, all participants were given two tablets. The trial sponsor, investigators, participants, and the study staff who provided the study drugs, assessed the outcomes, and collected the data were masked to group assignment. The primary efficacy outcome was incident HIV infection, which was assessed when all participants had completed 48 weeks of follow-up and half of all participants had completed 96 weeks of follow-up. This full analysis set included all randomly assigned participants who had received at least one dose of the assigned study drug and had at least one post-baseline HIV test. Non-inferiority of emtricitabine and tenofovir alafenamide to emtricitabine and tenofovir disoproxil fumarate was established if the upper bound of the 95·003% CI of the HIV incidence rate ratio (IRR) was less than the prespecified non-inferiority margin of 1·62. We prespecified six secondary bone mineral density and renal biomarker safety endpoints to evaluate using the safety analysis set. This analysis set included all randomly assigned participants who had received at least one dose of the assigned study drug. This trial is registered with ClinicalTrials.gov, NCT02842086, and is no longer recruiting. FINDINGS: Between Sept 13, 2016, and June 30, 2017, 5387 (92%) of 5857 participants were randomly assigned and received emtricitabine and tenofovir alafenamide (n=2694) or emtricitabine and tenofovir disoproxil fumarate (n=2693). At the time of the primary efficacy analysis (ie, when all participants had completed 48 weeks and 50% had completed 96 weeks) emtricitabine and tenofovir alafenamide was non-inferior to emtricitabine and tenofovir disoproxil fumarate for HIV prevention, as the upper limit of the 95% CI of the IRR, was less than the prespecified non-inferiority margin of 1·62 (IRR 0·47 [95% CI 0·19-1·15]). After 8756 person-years of follow-up, 22 participants were diagnosed with HIV, seven participants in the emtricitabine and tenofovir alafenamide group (0·16 infections per 100 person-years [95% CI 0·06-0·33]), and 15 participants in the emtricitabine and tenofovir disoproxil fumarate group (0·34 infections per 100 person-years [0·19-0·56]). Both regimens were well tolerated, with a low number of participants reporting adverse events that led to discontinuation of the study drug (36 [1%] of 2694 participants in the emtricitabine and tenofovir alafenamide group vs 49 [2%] of 2693 participants in the emtricitabine and tenofovir disoproxil fumarate group). Emtricitabine and tenofovir alafenamide was superior to emtricitabine and tenofovir disoproxil fumarate in all six prespecified bone mineral density and renal biomarker safety endpoints. INTERPRETATION: Daily emtricitabine and tenofovir alafenamide shows non-inferior efficacy to daily emtricitabine and tenofovir disoproxil fumarate for HIV prevention, and the number of adverse events for both regimens was low. Emtricitabine and tenofovir alafenamide had more favourable effects on bone mineral density and biomarkers of renal safety than emtricitabine and tenofovir disoproxil fumarate. FUNDING: Gilead Sciences.

Evidence of an Association of Increases in Pre-exposure Prophylaxis Coverage With Decreases in Human Immunodeficiency Virus Diagnosis Rates in the United States, 2012-2016.

BACKGROUND: Annual human immunodeficiency virus (HIV) diagnoses in the United States (US) have plateaued since 2013. We assessed whether there is an association between uptake of pre-exposure prophylaxis (PrEP) and decreases in HIV diagnoses. METHODS: We used 2012-2016 data from the US National HIV Surveillance System to estimate viral suppression (VS) and annual percentage change in diagnosis rate (EAPC) in 33 jurisdictions, and data from a national pharmacy database to estimate PrEP uptake. We used Poisson regression with random effects for state and year to estimate the association between PrEP coverage and EAPC: within jurisdictional quintiles grouped by changes in PrEP coverage, regressing EAPC on time; and among all jurisdictions, regressing EAPC on both time and jurisdictional changes in PrEP coverage with and without accounting for changes in VS. RESULTS: From 2012 to 2016, across the 10 states with the greatest increases in PrEP coverage, the EAPC decreased 4.0% (95% confidence interval [CI], -5.2% to -2.9%). On average, across the states and District of Columbia, EAPC for a given year decreased by 1.1% (95% CI, -1.77% to -.49%) for an increase in PrEP coverage of 1 per 100 persons with indications. When controlling for VS, the state-specific EAPC for a given year decreased by 1.3% (95% CI, -2.12% to -.57%) for an increase in PrEP coverage of 1 per 100 persons with indications. CONCLUSIONS: We found statistically significant associations between jurisdictional increases in PrEP coverage and decreases in EAPC independent of changes in VS, which supports bringing PrEP use to scale in the US to accelerate reductions in HIV infections.

Efficacy of Oral Tenofovir Alafenamide/Emtricitabine Combination or Single-Agent Tenofovir Alafenamide Against Vaginal Simian Human Immunodeficiency Virus Infection in Macaques.

BACKGROUND: Tenofovir alafenamide (TAF)-based regimens are being evaluated for pre-exposure prophylaxis (PrEP). We used a macaque model of repeated exposures to simian human immunodeficiency virus (SHIV) to investigate whether TAF alone or the combination of TAF and emtricitabine (FTC) can prevent vaginal infection. METHODS: Pigtail macaques were exposed vaginally to SHIV162p3 once a week for up to 15 weeks. Animals received clinical doses of FTC/TAF (n = 6) or TAF (n = 9) orally 24 hours before and 2 hours after each weekly virus exposure. Infection was compared with 21 untreated controls. RESULTS: Five of the 6 animals in the FTC/TAF and 4 of the 9 animals in the TAF alone group were protected against infection (P = .001 and P = .049, respectively). The calculated efficacy of FTC/TAF and TAF was 91% (95% confidence interval [CI], 34.9%-98.8%) and 57.8% (95% CI, -8.7% to 83.6%), respectively. Infection in FTC/TAF but not TAF-treated macaques was delayed relative to controls (P = .005 and P = .114). Median tenofovir diphosphate (TFV-DP) levels in peripheral blood mononuclear cells (PBMCs) were similar among infected and uninfected macaques receiving TAF PrEP (351 and 143 fmols/106 cells, respectively; P = .921). CONCLUSIONS: Emtricitabine/TAF provided a level of protection against vaginal challenge similar to FTC/TFV disoproxil fumarate combination in the macaque model. Our results support the clinical evaluation of FTC/TAF for PrEP in women.

Single-dose pharmacokinetics of tenofovir alafenamide and its active metabolite in the mucosal tissues.

Objectives: Tenofovir alafenamide, a prodrug of tenofovir, produces higher PBMC concentrations of tenofovir diphosphate (tenofovir-dp) than tenofovir disoproxil fumarate. To understand tenofovir alafenamide's mucosal tissue distribution and its implications for pre-exposure prophylaxis, we characterized tenofovir-dp in female genital tract (FGT) and lower gastrointestinal (GI) tissues. Methods: Healthy seronegative women were given 5, 10 or 25 mg of tenofovir alafenamide ( n = 8/group). Each participant provided plasma, PBMC and cervical, vaginal and rectal tissue samples over 14 days. Plasma, cell lysate and tissue homogenate concentrations were analysed by LC-MS/MS. Dose proportionality was declared in plasma and PBMCs if the natural log AUC versus natural log dose regression line 90% CI was within 0.57-1.43. In vitro tenofovir-dp formation was assessed in PBMCs and ectocervical (Ect1/E6E7) and vaginal (VK2/E6E7) cells incubated in 0.5 and 10 µM tenofovir alafenamide or tenofovir. clinicaltrials.gov: NCT02357602. Results: Following single doses of 5, 10 and 25 mg, median (IQR) tenofovir plasma AUC 0-14 days was 52.8 (49.5-59.6), 78.1 (68.2-86.9) and 169.7 (131.2-211.4) ng·h/mL and tenofovir-dp PBMC AUC 0-14 days was 2268 (1519-4090), 4584 (3113-5734) and 9306 (6891-10785) fmol·h/10 6 cells, respectively. Tenofovir was quantifiable in 52% and 92% of FGT and GI tissues, whereas tenofovir-dp was quantifiable in only 5% and 19% of FGT and GI tissues, respectively. Plasma tenofovir and PBMC tenofovir-dp were dose proportional (90% CI = 0.87-1.15 and 0.62-1.02, respectively). In vitro tenofovir-dp was 1.7-17-fold higher in epithelial cells than PBMCs. Conclusions: After tenofovir alafenamide dosing in vivo , tenofovir-dp was unquantifiable in most tissues (91%) although cervical and vaginal epithelial cells efficiently formed tenofovir-dp from tenofovir alafenamide in vitro . These findings warrant further investigation of tenofovir alafenamide's pharmacology.

Concordance of HIV-1 RNA Values by Amplicor and TaqMan 2.0 in Patients With Confirmed Suppression in Clinical Trials.

BACKGROUND: The COBAS AMPLICOR HIV-1 MONITOR Test, version 1.5 (Amplicor) has been replaced with the COBAS AmpliPrep/COBAS TaqMan HIV-1 Test, version 2.0 (TaqMan 2.0), a real-time polymerase chain reaction human immunodeficiency virus type 1 (HIV-1) assay with higher sensitivity and broader dynamic range. HIV-1 RNA values at the 50 copies/mL cutoff drive major patient management decisions and clinical study outcomes. METHODS: A total of 2217 samples were collected from 1922 HIV-1-infected subjects taking antiretroviral therapy for at least 48 weeks and had at least 2 consecutive samples with HIV-1 RNA <50 copies/mL by Amplicor from 7 recent clinical trials. HIV-1 RNA results were obtained from the Amplicor and TaqMan 2.0 assays in parallel by a reference laboratory. RESULTS: The overall concordance between assay results was 96% at the cutoff of 50 copies/mL. However, statistically significant discordance at the 50 copies/mL cutoff was found between the assays for 3.9% of samples (n = 87). By TaqMan 2.0, virologic failure defined as HIV-1 RNA ≥ 50 copies/mL was reported for 2.8% more samples than Amplicor. Of these 87 samples, 68 samples fell within the predicted range of assay variability. Retesting of HIV-1 RNA by TaqMan 2.0 confirmed the discordance in only 28 of the 87 samples. CONCLUSIONS: The TaqMan 2.0 assay reports fewer subjects below the clinical endpoint of HIV-1 RNA <50 copies/mL in HIV clinical trials than the Amplicor assay. This difference must be considered when assessing disease progression, designing clinical trials, and comparisons with historical trials that used the Amplicor assay.

Tenofovir alafenamide versus tenofovir disoproxil fumarate, coformulated with elvitegravir, cobicistat, and emtricitabine, for initial treatment of HIV-1 infection: two randomised, double-blind, phase 3, non-inferiority trials.

BACKGROUND: Tenofovir disoproxil fumarate can cause renal and bone toxic effects related to high plasma tenofovir concentrations. Tenofovir alafenamide is a novel tenofovir prodrug with a 90% reduction in plasma tenofovir concentrations. Tenofovir alafenamide-containing regimens can have improved renal and bone safety compared with tenofovir disoproxil fumarate-containing regimens. METHODS: In these two controlled, double-blind phase 3 studies, we recruited treatment-naive HIV-infected patients with an estimated creatinine clearance of 50 mL per min or higher from 178 outpatient centres in 16 countries. Patients were randomly assigned (1:1) to receive once-daily oral tablets containing 150 mg elvitegravir, 150 mg cobicistat, 200 mg emtricitabine, and 10 mg tenofovir alafenamide (E/C/F/tenofovir alafenamide) or 300 mg tenofovir disoproxil fumarate (E/C/F/tenofovir disoproxil fumarate) with matching placebo. Randomisation was done by a computer-generated allocation sequence (block size 4) and was stratified by HIV-1 RNA, CD4 count, and region (USA or ex-USA). Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug were included in the primary intention-to-treat efficacy and safety analyses. The main outcomes were the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by the the US Food and Drug Adminstration (FDA) snapshot algorithm (pre-specified non-inferiority margin of 12%) and pre-specified renal and bone endpoints at 48 weeks. These studies are registered with ClinicalTrials.gov, numbers NCT01780506 and NCT01797445. FINDINGS: We recruited patients from Jan 22, 2013, to Nov 4, 2013 (2175 screened and 1744 randomly assigned), and gave treatment to 1733 patients (866 given E/C/F/tenofovir alafenamide and 867 given E/C/F/tenofovir disoproxil fumarate). E/C/F/tenofovir alafenamide was non-inferior to E/C/F/tenofovir disoproxil fumarate, with 800 (92%) of 866 patients in the tenofovir alafenamide group and 784 (90%) of 867 patients in the tenofovir disoproxil fumarate group having plasma HIV-1 RNA less than 50 copies per mL (adjusted difference 2·0%, 95% CI -0·7 to 4·7). Patients given E/C/F/tenofovir alafenamide had significantly smaller mean serum creatinine increases than those given E/C/F/tenofovir disoproxil fumarate (0·08 vs 0·12 mg/dL; p<0·0001), significantly less proteinuria (median % change -3 vs 20; p<0·0001), and a significantly smaller decrease in bone mineral density at spine (mean % change -1·30 vs -2·86; p<0·0001) and hip (-0·66 vs -2·95; p<0·0001) at 48 weeks. INTERPRETATION: Through 48 weeks, more than 90% of patients given E/C/F/tenofovir alafenamide or E/C/F/tenofovir disoproxil fumarate had virological success. Renal and bone effects were significantly reduced in patients given E/C/F/tenofovir alafenamide. Although these studies do not have the power to assess clinical safety events such as renal failure and fractures, our data suggest that E/C/F/tenofovir alafenamide will have a favourable long-term renal and bone safety profile. FUNDING: Gilead Sciences.

Rare emergence of drug resistance in HIV-1 treatment-naïve patients after 48 weeks of treatment with elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide.

Tenofovir alafenamide (TAF), a novel prodrug of the NtRTI tenofovir (TFV), delivers TFV-diphosphate (TFV-DP) to target cells more efficiently than the current prodrug, tenofovir disoproxil fumarate (TDF), with a 90% reduction in TFV plasma exposure. TAF, within the fixed dose combination of elvitegravir /cobicistat / emtricitabine (FTC)/TAF (E/C/F/TAF), has been evaluated in one Phase 2 and two Phase 3 randomized, double-blinded studies in HIV-infected treatment-naive patients, comparing E/C/F/TAF to E/C/F/TDF. In these studies, the TAF-containing group demonstrated non-inferior efficacy to the TDF-containing comparator group with 91.9% of E/C/F/TAF patients having <50 copies/mL of HIV-1 RNA at week 48. An integrated resistance analysis across these three studies was conducted, including HIV-1 genotypic analysis at screening, and genotypic/phenotypic analysis for patients with HIV-1 RNA>400 copies/mL at virologic failure. Pre-existing primary resistance-associated mutations (RAMs) were observed at screening among the 1903 randomized and treated patients: 7.5% had NRTI-RAMs, 18.2% had NNRTI-RAMs, and 3.4% had primary PI-RAMs. Pre-treatment RAMs did not influence treatment response at Week 48. In the E/C/F/TAF group, resistance development was rare; seven patients (0.7%, 7/978) developed NRTI-RAMs, five of whom (0.5%, 5/978) also developed primary INSTI-RAMs. In the E/C/F/TDF group, resistance development was also rare; seven patients (0.8%, 7/925) developed NRTI-RAMs, four of whom (0.4%, 4/925) also developed primary INSTI-RAMs. An additional analysis by deep sequencing in virologic failures revealed minimal differences compared to population sequencing. Overall, resistance development was rare in E/C/F/TAF-treated patients, and the pattern of emergent mutations was similar to E/C/F/TDF.

Combination therapy with telaprevir for chronic hepatitis C virus genotype 1 infection in patients with HIV: a randomized trial.

BACKGROUND: Telaprevir (TVR) plus peginterferon-α2a (PEG-IFN-α2a) and ribavirin substantially increases treatment efficacy for genotype 1 chronic hepatitis C virus (HCV) infection versus PEG-IFN-α2a-ribavirin alone. Its safety and efficacy in patients with HCV and HIV-1 are unknown. OBJECTIVE: To assess the safety and efficacy of TVR plus PEG-IFN-α2a-ribavirin in patients with genotype 1 HCV and HIV-1 and to evaluate pharmacokinetics of TVR and antiretrovirals during coadministration. DESIGN: Phase 2a, randomized, double-blind, placebo-controlled study. (ClinicalTrials.gov: NCT00983853). SETTING: 16 international multicenter sites. PATIENTS: 62 patients with HCV genotype 1 and HIV-1 who were HCV treatment-naive and receiving 0 or 1 of 2 antiretroviral regimens were randomly assigned to TVR plus PEG-IFN-α2a-ribavirin or placebo plus PEG-IFN-α2a-ribavirin for 12 weeks, plus 36 weeks of PEG-IFN-α2a-ribavirin. MEASUREMENTS: HCV RNA concentrations. RESULTS: Pruritus, headache, nausea, rash, and dizziness were higher with TVR plus PEG-IFN-α2a-ribavirin during the first 12 weeks. During this period, serious adverse events occurred in 5% (2 in 38) of those receiving TVR plus PEG-IFN-α2a-ribavirin and 0% (0 in 22) of those receiving placebo plus PEG-IFN-α2a-ribavirin; the same number in both groups discontinued treatment due to adverse events. Sustained virologic response occurred in 74% (28 in 38) of patients receiving TVR plus PEG-IFN-α2a-ribavirin and 45% (10 in 22) of patients receiving placebo plus PEG-IFN-α2a-ribavirin. Rapid HCV suppression was seen with TVR plus PEG-IFN-α2a-ribavirin (68% [26 in 38 patients] vs. 0% [0 in 22 patients] undetectable HCV RNA levels by week 4). Two patients had on-treatment HCV breakthrough with TVR-resistant variants. Patients treated with antiretroviral drugs had no HIV breakthroughs; antiretroviral exposure was not substantially modified by TVR. LIMITATION: Small sample size and appreciable dropout rate. CONCLUSION: In patients with HCV and HIV-1, more adverse events occurred with TVR versus placebo plus PEG-IFN-α2a-ribavirin; these were similar in nature and severity to those in patients with HCV treated with TVR. With or without concomitant antiretrovirals, sustained virologic response rates were higher in patients treated with TVR versus placebo plus PEG-IFN-α2a-ribavirin.

Safety and Pharmacokinetics of a Tenofovir Alafenamide Fumarate-Emtricitabine based Oral Antiretroviral Regimen for Prevention of HIV Acquisition in Women: A Randomized Controlled Trial.

BACKGROUND: Daily oral emtricitabine (FTC, F)/tenofovir disoproxil fumarate (TDF) combination is approved for HIV pre-exposure prophylaxis (PrEP) in men and women. Tenofovir alafenamide fumarate (TAF) is a newer, more potent prodrug of tenofovir (TFV), and in combination with FTC, has recently been approved for prevention of HIV through rectal transmission. METHODS: This Phase I, prospective, interventional, randomized study was conducted in three clinical sites: PROFAMILIA, Santo Domingo, Dominican Republic; University of Pittsburgh and Eastern Virginia Medical School. We assessed the multi-compartmental pharmacokinetics (primary outcome) and safety (secondary outcome) among HIV uninfected women randomized to F/TDF (200mg/300mg) or F/TAF (200mg/25mg; F/TAF25) (n=24) in a single dose phase (SDP) and F/TDF, F/TAF (200mg/10mg; F/TAF10), or F/TAF25 (n=75) in a multiple dose (14 daily doses) phase (MDP). We described PK parameters in plasma, peripheral blood mononuclear cells (PBMCs), and cervicovaginal (CV) and rectal fluids and tissues. ClinicalTrials.gov #NCT02904369, completed. FINDINGS: Recruitment for the study began on 5 October 2016. The first participant was enrolled on 6 October 2016 and the last participant completed the study 21 November 2017. PLASMA: TFV concentrations area under curve (AUC) were ~20 fold lower following F/TAF versus F/TDF. TFV-diphosphate (TFV-DP) AUC concentrations in PBMCs were 7-fold higher with F/TAF25 versus F/TDF. Median TFV-DP concentrations in vaginal tissue (4hours post last dose) were approximately 6-fold higher with F/TAF25 versus F/TDF. TFV and TFV-DP were lower with F/TAF versus F/TDF in rectal tissue. Concentrations of FTC and FTC-triphosphate (FTC-TP) were similar across matrices and treatment arms. Gastrointestinal adverse events (AEs) occurred more frequently in F/TDF users (44.0%) than in either F/TAF group (11.5 and 12.0%). INTERPRETATION: F/TAF was safe and well-tolerated. TFV-DP concentrations were higher in PBMCs and similar or higher (4h post dose) in female genital tract tissues for F/TAF versus F/TDF. High FTC and FTC-TP concentrations in all compartments support the potential of F/TAF as a new PrEP combination for women.

Pharmacokinetic characterization of three doses of tipranavir boosted with ritonavir on highly active antiretroviral therapy in treatment-experienced HIV-1 patients.

PURPOSE: This study characterized the pharmacokinetic effects, safety, and antiretroviral activity of three different doses of the nonpeptidic protease inhibitor tipranavir, in combination with ritonavir administered twice daily for 28 days, on a number of triple-combination regimens containing a nonnucleoside reverse transcriptase inhibitor (efavirenz or nevirapine) plus two nucleoside reverse transcriptase inhibitors (abacavir, didanosine, lamivudine, stavudine, and zidovudine) or a three nucleoside reverse transcriptase inhibitor combination (zidovudine, lamivudine, and abacavir). METHODS: The study enrolled 208 HIV-1-positive patients who had been on stable antiretroviral treatment for at least 12 weeks prior to study entry and had an HIV-1 RNA load of delta 20,000 copies/mL. The patients were randomized to receive one of three dose combinations of tipranavir and ritonavir (1250/100 mg, 750/100 mg, and 250/200 mg) in addition to their antiretroviral (ARV) regimen for the next 22 days. The effects of twice-daily tipranavir and ritonavir combinations on the steady-state pharmacokinetics of the antiretrovirals were assessed by comparing pharmacokinetic parameters at baseline and after 3 weeks of coadministration. RESULTS: No clinically relevant changes were observed in the Cmin, Cmax, or AUC parameters for nevirapine, efavirenz, lamivudine, stavudine, or didanosine, when coadministered with tipranavir and ritonavir at the dose combinations studied. All three dose combinations of tipranavir and ritonavir decreased the systemic exposure of abacavir (by 35% to 44%) and zidovudine (by 31% to 42%). Consistent with previous tipranavir studies, gastrointestinal adverse events were those most frequently observed. These reactions tended to be mild, with the majority being of Grade 1, and only 8 being of Grade 3 or 4 in intensity. Virologic response improved from 40.4% of participants at baseline with <50 copies/mL to 67.6% at Day 28 of study following addition of tipranavir and ritonavir. CONCLUSIONS: Tipranavir coadministered with ritonavir has been demonstrated to be safe, effective, and pose little potential for clinically meaningful drug interactions when added to the highly active antiretroviral therapy regimens containing nevirapine, efavirenz, lamivudine, stavudine, or didanosine.

Policy- and county-level associations with HIV pre-exposure prophylaxis use, the United States, 2018.

PURPOSE: HIV pre-exposure prophylaxis (PrEP) is highly efficacious, and yet most individuals indicated for it are not currently using it. To provide guidance for health policymakers, researchers, and community advocates, we developed county-level PrEP use estimates and assessed locality and policy associations. METHODS: Using data from a national aggregator, we applied a validated crosswalk procedure to generate county-level estimates of PrEP users in 2018. A multilevel Poisson regression explored associations between PrEP use and (1) state policy variables of Medicaid expansion and state Drug Assistance Programs (PrEP-DAPs) and (2) county-level characteristics from the U.S. Census Bureau. Outcomes were PrEP per population (prevalence) and PrEP-to-need ratio (PnR), defined as the ratio of PrEP users per new HIV diagnosis. Higher levels of PrEP prevalence or PnR indicate more PrEP users relative to the total population or estimated need, respectively. RESULTS: Our 2018 county-level data set included a total of 188,546 PrEP users in the United States. Nationally, PrEP prevalence was 70.3/100,000 population and PnR was 4.9. In an adjusted model, counties with a 5% higher proportion of black residents had 5% lower PnR (rate ratio (RR): 0.95, 95% confidence interval (CI): 0.93, 0.96). Similarly, counties with higher concentration of residents uninsured or living in poverty had lower PnR. Relative to states without Medicaid expansion or PrEP-DAPs, states with only one of those programs had 25% higher PrEP prevalence (RR: 1.25, 95% CI: 1.09, 1.45), and states with both programs had 99% higher PrEP prevalence (RR: 1.99, 95% CI: 1.60, 2.48). There was a significant linear trend across the three policy groups, and similar findings for the relation between PnR and the policy groups. CONCLUSIONS: In a data set comprising approximately 80% of PrEP users in the United States, we found that Medicaid expansion and PrEP-DAPs were associated with higher PrEP use in states that adopted those policies, after controlling for potential confounders. Future research should identify which components of PrEP support programs have the most success and how to best promote PrEP among groups most impacted by the epidemic. States should support the admirable health decisions of their residents to get on PrEP by implementing policies that facilitate access.

Methods for county-level estimation of pre-exposure prophylaxis coverage and application to the U.S. Ending the HIV Epidemic jurisdictions.

PURPOSE: Pre-exposure prophylaxis (PrEP) is a pillar of the US Department of Health and Human Services "Ending the HIV Epidemic" (EHE) initiative in 50 EHE jurisdictions (48 U.S. counties and two U.S. cities) and seven U.S. states with high numbers of HIV diagnoses rates in rural areas. Current data systems do not provide data on PrEP uptake in counties or cities. METHODS: We report on PrEP users at the county level. Data from a large, commercial pharmacy database were used; we applied the U.S. Census Bureau's method to allocate PrEP users within a ZIP3 into counties and validated the results. We report counts and rates of PrEP users in 2018 for all EHE jurisdictions. We used joinpoint regression to model the estimated annual percent change in PrEP use for each jurisdiction and state. RESULTS: 93,156 people in the 50 EHE jurisdictions used PrEP in 2018; 94% were men and 39% were aged 25-34 years. There was more than an 80-fold difference in the range of rates of PrEP use per 100,000 population among the EHE jurisdictions (range: 8-644 per 100,000 population; median 93 per 100,000 population). PrEP use increased from 2012 to 2018 in all EHE counties and states. At current rates of growth of PrEP use, 94% of EHE counties and jurisdictions will reach their National HIV/AIDS Strategy goals of a 500% increase in PrEP use in 2020. EHE states had less variation in rates of PrEP use (range: 29-51/100,000 population; median 32/100,000 population). CONCLUSIONS: At the outset of a major U.S. government program to reduce HIV infections, rates of PrEP use are highly variable among the 50 EHE jurisdictions. Data from commercial prescription databases will be a useful public resource to understand progress in promoting use of PrEP as part of the EHE initiative and evaluating progress in PrEP use across health jurisdictions.

Intracellular Tenofovir-Diphosphate and Emtricitabine-Triphosphate in Dried Blood Spots Following Tenofovir Alafenamide: The TAF-DBS Study.

BACKGROUND: Tenofovir alafenamide (TAF), in combination with FTC, was recently approved for PrEP in the United States. The objective of this study was to assess the relationship between tenofovir-diphosphate (TFV-DP) and emtricitabine-triphosphate (FTC-TP) in dried blood spots (DBS) with adherence to TAF/FTC. METHODS: TAF-DBS was a randomized, crossover clinical study of TFV-DP in DBS, following directly observed dosing of 33%, 67%, or 100% of daily TAF (25 mg)/FTC (200 mg). Healthy volunteers were randomized to 2 different, 12-week dosing regimens, separated by a 12-week washout. DBS were collected weekly. TFV-DP and FTC-TP were extracted from two 7-mm punches and assayed with LC-MS/MS. RESULTS: Thirty-seven participants (17 female, 7 African American, and 6 Hispanic) were included. TFV-DP exhibited a mean half-life of 20.8 days (95% confidence interval: 19.3 to 21.3). The slope for TFV-DP versus dosing arm was 1.14 (90% confidence interval: 1.07 to 1.21). The mean (SD) TFV-DP after 12 weeks was 657 (186), 1451 (501), and 2381 (601) fmol/2 7-mm punches for the 33%, 67%, and 100% arms. The following adherence interpretations are proposed: <450 fmol/punches, <2 doses/wk; 450-949 fmol/punches, 2-3 doses/wk; 950-1799 fmol/punches, 4-6 doses/wk; and ≥1800 fmol/punches, 7 doses/wk. FTC-TP was quantifiable for 1 week after drug cessation in 50%, 92%, and 100% of participants in the 33%, 67%, and 100% arms, respectively. CONCLUSION: TFV-DP in DBS after TAF/FTC exhibited a long half-life and was linearly associated with dosing, similar to its predecessor tenofovir disoproxil fumarate. FTC-TP was quantifiable for up to 1 week after drug cessation. Together, these moieties provide complementary measures of cumulative adherence and recent dosing for TAF/FTC.

Atherosclerotic Cardiovascular Disease Risk Profile of Tenofovir Alafenamide Versus Tenofovir Disoproxil Fumarate.

BACKGROUND: In human immunodeficiency virus (HIV) treatment, tenofovir alafenamide (TAF) is associated with greater increases in all fasting cholesterol subgroups compared with tenofovir disoproxil fumarate (TDF). Because lipid abnormalities may contribute to cardiovascular morbidity and mortality, cardiovascular risk assessment is integral to routine HIV care. This post hoc study evaluates the impact of lipid changes on predicted atherosclerotic cardiovascular disease (ASCVD) risk and statin eligibility in treatment-naive adults living with HIV treated with TAF or TDF. METHODS: Participants (N = 1744) were randomized (1:1) to initiate TAF or TDF, each coformulated with elvitegravir/cobicistat/emtricitabine (studies GS-US-292-0104 and GS-US-292-0111). Eligibility for statin therapy and estimated 10-year ASCVD risk among adults aged 40-79 years treated with TAF or TDF for 96 weeks (W96) were analyzed based on American College of Cardiology/American Heart Association Pooled Cohort Equations. Categorical shifts in 10-year ASCVD risk from <7.5% to ≥7.5% by W96 on TAF versus TDF were calculated. RESULTS: Participants initiating TAF versus TDF in the overall study population showed small but significant increases in median fasting lipid parameters at W96, including total cholesterol (191 vs 177 mg/dL; P < .001), low-density lipoprotein ([LDL] 119 vs 112 mg/dL; P < .001), and high-density lipoprotein ([HDL] 51 vs 48 mg/dL; P < .001), respectively. At baseline, 18% and 23% on TAF versus TDF had a 10-year ASCVD risk score ≥7.5%, with mean risk scores low overall for TAF versus TDF at baseline (4.9% vs 5.4%; P = .35) and W96 (6.1% vs 6.2%; P = .04). Increases in ASCVD risk from baseline to W96 were driven by both increasing age and changes in total cholesterol (TC) and HDL cholesterol. At W96, TC/HDL ratios (median) were 3.7 for both groups (P = .69). There was no difference between shifts in categorical risk for TAF versus TDF (9% vs 5%; P = .19). Eligibility for high-intensity statin therapy were similar for TAF versus TDF groups (19% vs 21%; P = .47). CONCLUSIONS: Lipid changes with TAF as part of coformulated regimens do not substantively affect CVD risk profiles compared with TDF.

Estimation of new HIV diagnosis rates among high-risk, PrEP-eligible individuals using HIV surveillance data at the Metropolitan Statistical Area level in the United States.

INTRODUCTION: New HIV diagnoses have fallen in the past decade due to increased HIV testing, earlier diagnosis, earlier antiretroviral treatment, improved linkage to care and engagement in care, and the recent increased uptake of pre-exposure prophylaxis (PrEP). We propose a novel method to compute the rate of new HIV diagnoses at the Metropolitan Statistical Area (MSA) level in the US to support the evaluation of comprehensive treatment and prevention efforts over time. METHODS: The number of new HIV diagnoses, number of individuals with a PrEP indication and aggregated person-time exposed to PrEP during the years 2012 to 2017 were used to compute a new HIV diagnosis rate for people at risk of HIV excluding those already on PrEP for the 105 MSAs in the US with published HIV surveillance data. In our calculation of person-time with a PrEP indication, time-at-risk excluded time on PrEP and time after an HIV diagnosis. We used a multivariate Poisson regression model to estimate HIV diagnosis rates by year and location. RESULTS: From 2012 to 2017, the aggregate HIV diagnoses rate among high-risk individuals with an indication for PrEP in the 105 MSAs decreased from 4.14 per 100 person-years (PY) (95% CI 4.10 to 4.19) to 3.26 per 100 PY (95% CI 3.22 to 3.30). For the 25 US MSAs that overlapped with an ongoing large randomized clinical trial of PrEP in men who have sex with men (MSM), the HIV diagnosis rate from 2012 to 2017 decreased from 4.86 per 100 PY (95% CI 4.80 to 4.93) to 3.61 per 100 PY (95% CI 3.56 to 3.66), a decline that was more rapid than in non-study MSAs (IRR for trial site 1.19, 95% CI 1.18 to 1.20). CONCLUSIONS: We propose a model to estimate the background HIV diagnosis rate in people at risk for HIV and with a PrEP indication in US MSAs (excluding those on PrEP) using publically available surveillance data which can evaluate trends over time. Data generated using this methodology could be used by policy makers and local HIV prevention specialists to evaluate and monitor their prevention efforts for the population at risk in their communities.

Plasma concentration of neurofilament light chain protein decreases after switching from tenofovir disoproxil fumarate to tenofovir alafenamide fumarate.

BACKGROUND: Because tenofovir alafenamide (TAF) leads to significantly lower plasma tenofovir concentrations than tenofovir disoproxil fumarate (TDF) and is a stronger substrate for P-glycoprotein (P-gp) than TDF, TAF could lead to decreased central nervous system (CNS) tenofovir exposure than TDF. We aimed to determine if switching from TDF to TAF increases the risk of neuronal injury, by quantifying plasma levels of neurofilament light protein (NfL), a sensitive marker of neuronal injury in HIV CNS infection. METHODS: Plasma NfL concentration was measured at baseline, week 24, and week 84 in stored plasma samples from 416 participants (272 switching to elvitegravir (E)/cobicistat (C)/emtricitabine (F)/TAF and 144 continuing E/C/F/TDF) enrolled in the randomized, active-controlled, multicenter, open-label, noninferiority Gilead GS-US-292-0109 trial. RESULTS: While plasma NfL levels in both groups were within the normal range, we found a small but significant decrease in the E/C/F/TAF arm after 84 weeks from a geometric mean of 9.3 to 8.8 pg/mL (5.4% decline, 95% CI 2.0-8.4, p = 0.002). This change was significantly different (p = 0.001) from that of the E/C/F/TDF arm, in which plasma NfL concentration changed from 9.7 pg/mL at baseline to 10.2 pg/mL at week 84 (5.8% increase, 95% CI -0.8-12.9, p = 0.085). This increase is in line with what could be expected in normal ageing. Plasma NfL concentrations significantly correlated with age. No correlation was found between plasma NfL and serum creatinine. CONCLUSIONS: We found no biomarker evidence of CNS injury when switching from TDF to TAF. It is unclear whether the small decrease in plasma NfL found after switch to TAF is of any clinical relevance, particularly with plasma NfL levels in both arms remaining within the limits found in HIV-negative controls. These results indicate that switching from TDF to TAF appears safe with regard to neuronal injury.