Last data update: Sep 16, 2024. (Total: 47680 publications since 2009)
Records 1-30 (of 78 Records) |
Query Trace: Lerma S [original query] |
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Defining blood hematology reference values in female pig-tailed macaques (Macaca nemestrina) using the Isolation Forest algorithm
Kim D , Derton A , Khalil G , Pan Y , Bachman S , Kelley K , Garcίa-Lerma G , Dobard CW , Daly MB . J Med Primatol 2024 53 (4) e12723 BACKGROUND: Pig-tailed macaques (PTMs) are commonly used as preclinical models to assess antiretroviral drugs for HIV prevention research. Drug toxicities and disease pathologies are often preceded by changes in blood hematology. To better assess the safety profile of pharmaceuticals, we defined normal ranges of hematological values in PTMs using an Isolation Forest (iForest) algorithm. METHODS: Eighteen female PTMs were evaluated. Blood was collected 1-24 times per animal for a total of 159 samples. Complete blood counts were performed, and iForest was used to analyze the hematology data to detect outliers. RESULTS: Median, IQR, and ranges were calculated for 13 hematology parameters. From all samples, 22 outliers were detected. These outliers were excluded from the reference index. CONCLUSIONS: Using iForest, we defined a normal range for hematology parameters in female PTMs. This reference index can be a valuable tool for future studies evaluating drug toxicities in PTMs. |
Weekly oral tenofovir alafenamide protects macaques from vaginal and rectal Simian HIV infection
Massud I , Nishiura K , Ruone S , Holder A , Dinh C , Lipscomb J , Mitchell J , Khalil GM , Heneine W , Garcia-Lerma JG , Dobard CW . Pharmaceutics 2024 16 (3) Pre-exposure prophylaxis (PrEP) with a weekly oral regimen of antiretroviral drugs could be a suitable preventative option for individuals who struggle with daily PrEP or prefer not to use long-acting injectables. We assessed in macaques the efficacy of weekly oral tenofovir alafenamide (TAF) at doses of 13.7 or 27.4 mg/kg. Macaques received weekly oral TAF for six weeks and were exposed twice-weekly to SHIV vaginally or rectally on day 3 and 6 after each dose. Median TFV-DP levels in PBMCs following the 13.7 mg/kg dose were 3110 and 1137 fmols/10(6) cells on day 3 and 6, respectively. With the 27.4 mg/kg dose, TFV-DP levels were increased (~2-fold) on day 3 and 6 (6095 and 3290 fmols/10(6) cells, respectively). Both TAF doses (13.7 and 27.4 mg/kg) conferred high efficacy (94.1% and 93.9%, respectively) against vaginal SHIV infection. Efficacy of the 27.4 mg/kg dose against rectal SHIV infection was 80.7%. We estimate that macaque doses of 13.7 and 27.4 mg/kg are equivalent to approximately 230 and 450 mg of TAF in humans, respectively. Our findings demonstrate the effectiveness of a weekly oral PrEP regimen and suggest that a clinically achievable oral TAF dose could be a promising option for non-daily PrEP. |
Corrigendum to - "Single oral dose for HIV pre or post-exposure prophylaxis: user desirability and biological efficacy in macaques" [eBioMedicine 58(2020) 102894]
Massud I , Ruone S , Zlotorzynska M , Haaland R , Mills P , Cong ME , Kelley K , Johnson R , Holder A , Dinh C , Khalil G , Pan Y , Kelley CF , Sanchez T , Heneine W , García-Lerma JG . EBioMedicine 2024 101 105014 |
Author Correction: Ultra-long-acting in-situ forming implants with cabotegravir protect female macaques against rectal SHIV infection
Young IC , Massud I , Cottrell ML , Shrivastava R , Maturavongsadit P , Prasher A , Wong-Sam A , Dinh C , Edwards T , Mrotz V , Mitchell J , Seixas JN , Pallerla A , Thorson A , Schauer A , Sykes C , De la Cruz G , Montgomery SA , Kashuba ADM , Heneine W , Dobard CW , Kovarova M , Garcia JV , Garcίa-Lerma JG , Benhabbour SR . Nat Commun 2024 15 (1) 1054 |
Extended post-exposure protection against vaginal SHIV infection with tenofovir alafenamide fumarate/elvitegravir inserts in macaques
Makarova N , Singletary T , Peet MM , Mitchell J , Bachman S , Holder A , Dinh C , Lipscomb J , Agrahari V , Mendoza M , Pan Y , Heneine W , Clark MR , García-Lerma JG , Doncel GF , Smith JM . J Infect Dis 2023 Vaginal inserts that can be used on demand before or after sex may be a desirable HIV prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF/20mg) and elvitegravir (EVG/16mg) were highly protective against repeated SHIV vaginal exposures when administered to macaques 4h before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8h or 24h after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women. |
Pharmacokinetic study of islatravir and etonogestrel implants in macaques
Daly MB , Wong-Sam A , Li L , Krovi A , Gatto GJ , Norton C , Luecke EH , Mrotz V , Forero C , Cottrell ML , Schauer AP , Gary J , Nascimento-Seixas J , Mitchell J , van der Straten A , Heneine W , Garcίa-Lerma JG , Dobard CW , Johnson LM . Pharmaceutics 2023 15 (12) The prevention of HIV and unintended pregnancies is a public health priority. Multi-purpose prevention technologies capable of long-acting HIV and pregnancy prevention are desirable for women. Here, we utilized a preclinical macaque model to evaluate the pharmacokinetics of biodegradable ε-polycaprolactone implants delivering the antiretroviral islatravir (ISL) and the contraceptive etonogestrel (ENG). Three implants were tested: ISL-62 mg, ISL-98 mg, and ENG-33 mg. Animals received one or two ISL-eluting implants, with doses of 42, 66, or 108 µg of ISL/day with or without an additional ENG-33 mg implant (31 µg/day). Drug release increased linearly with dose with median [range] plasma ISL levels of 1.3 [1.0-2.5], 1.9 [1.2-6.3] and 2.8 [2.3-11.6], respectively. The ISL-62 and 98 mg implants demonstrated stable drug release over three months with ISL-triphosphate (ISL-TP) concentr54ations in PBMCs above levels predicted to be efficacious for PrEP. Similarly, ENG implants demonstrated sustained drug release with median [range] plasma ENG levels of 495 [229-1110] pg/mL, which suppressed progesterone within two weeks and showed no evidence of altering ISL pharmacokinetics. Two of the six ISL-98 mg implants broke during the study and induced implant-site reactions, whereas no reactions were observed with intact implants. We show that ISL and ENG biodegradable implants are safe and yield sufficient drug levels to achieve prevention targets. The evaluation of optimized implants with increased mechanical robustness is underway for improved durability and vaginal efficacy in a SHIV challenge model. |
Next generation 3D-printed intravaginal ring for prevention of HIV and unintended pregnancy
Young IC , Srinivasan P , Shrivastava R , Janusziewicz R , Thorson A , Cottrell ML , Sellers RS , Sykes C , Schauer A , Little D , Kelley K , Kashuba ADM , Katz D , Pyles RB , García-Lerma JG , Vincent KL , Smith J , Benhabbour SR . Biomaterials 2023 301 122260 Globally, there are 20 million adolescent girls and young women living with HIV who have limited access to long-acting, effective, women-controlled preventative methods. Additionally, although there are many contraceptive methods available, globally, half of all pregnancies remain unintended. Here we report the first 3D-printed multipurpose prevention technology (MPT) intravaginal ring (IVR) for HIV prevention and contraception. We utilized continuous liquid interface production (CLIP™) to fabricate MPT IVRs in a biocompatible silicone-based resin. Etonogestrel (ENG), ethinyl estradiol (EE), and islatravir (ISL) were loaded into the silicone poly(urethane) IVR in a controlled single step drug loading process driven by absorption. ENG/EE/ISL IVR promoted sustained release of drugs for 150 days in vitro and 14 days in sheep. There were no adverse MPT IVR-related findings of cervicovaginal toxicity or changes in vaginal biopsies or microbiome community profiles evaluated in sheep. Furthermore, ISL IVR in macaques promoted sustained release for 28 days with ISL-triphosphate levels above the established pharmacokinetic benchmark of 50-100 fmol/10(6) PBMCs. The ISL IVR was found to be safe and well tolerated in the macaques with no observed mucosal cytokine changes or alterations in peripheral CD4 T-cell populations. Collectively, the proposed MPT IVR has potential to expand preventative choices for young women and girls. |
Memory CD4 T cell subset organization in the female reproductive tract is regulated via the menstrual cycle through CCR5 signaling (preprint)
Swaims-Kohlmeier A , Wein AN , Hardnett FP , Sheth AN , Li ZRT , Williams ME , Radzio-Basu J , Zheng H , Dinh C , Haddad LB , Collins EMB , Lobby JL , Kost K , Hayward SL , Ofotokun I , Antia R , Scharer CD , Lowen AC , Garcia-Lerma JG , Kohlmeier JE . bioRxiv 2022 03 Despite their importance for immunity against sexually transmitted infections (STIs), the composition of the female reproductive tract (FRT) memory CD4 T cell population in response to changes in the local tissue environment during the menstrual cycle remains poorly defined. Here we show that across humans, non-human primates (NHP), and mice, FRT CD4 T cells comprise distinct subsets corresponding to migratory memory (TMM) and resident memory (TRM) cells. TMM display tissue-itinerant trafficking characteristics, restricted FRT tissue distribution, with distinct transcriptional properties and effector responses to infection. CD4 T cell subset fluctuations synchronized with cycle-driven proinflammatory changes within the local tissue environment and oral administration of a CCR5 antagonist inhibited cycle phase-specific migratory T cell surveillance. This study provides novel insights into the dynamic nature of FRT memory CD4 T cells and identifies the menstrual cycle as a key regulator of memory T cell defense at the site of STI exposure. Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. |
In Reply
Jatlaoui TC , Whiteman MK , Jeng G , Tepper NK , Curtis KM . Obstet Gynecol 2019 133 (3) 582-583 We appreciate the important considerations raised by Blumenthal and Lerma regarding our | recent publication.1 | We agree that continuation is an important programmatic outcome. | However, intrauterine device (IUD) reinsertion after expulsion may not be feasible for all | women owing to cost, insurance coverage, or logistical barriers. Therefore, expulsion is an | essential contributor to continuation, and these data may inform patient-centered counseling. | To provide information pertinent to U.S. practice, we included data on copper and | levonorgestrel IUDs that were ever available in the United States, rather than those included | in a recent review.2 | We agree that certain factors (eg, insertion technique and health care | provider experience) may influence expulsion risk; however, these factors were not | consistently reported by studies and therefore not included in our analysis. | We based our timing categories of postpartum IUD placement on U.S. Medical Eligibility | Criteria for Contraceptive Use recommendations.3 | The majority of data are reported by these | categories, and studies examining the early postpartum period (more than 10 minutes after | placental delivery to less than 4 weeks postpartum) did not provide sufficient data to | separate expulsion rates into additional time periods. Ideally, future studies will describe | outcomes, including uptake, expulsions, and continuation, associated with placements in the | delivery room, during the hospital stay, or at an early postpartum visit to better inform | postpartum contraception care and programs. Nonetheless, postpartum IUD placement is | safe at any time and can be provided based on the woman’s preference. |
Tracking COVID-19 in the United States with surveillance of aggregate cases and deaths
Khan D , Park M , Burkholder J , Dumbuya S , Ritchey MD , Yoon P , Galante A , Duva JL , Freeman J , Duck W , Soroka S , Bottichio L , Wellman M , Lerma S , Lyons BC , Dee D , Haile S , Gaughan DM , Langer A , Gundlapalli AV , Suthar AB . Public Health Rep 2023 333549231163531 Early during the COVID-19 pandemic, the Centers for Disease Control and Prevention (CDC) leveraged an existing surveillance system infrastructure to monitor COVID-19 cases and deaths in the United States. Given the time needed to report individual-level (also called line-level) COVID-19 case and death data containing detailed information from individual case reports, CDC designed and implemented a new aggregate case surveillance system to inform emergency response decisions more efficiently, with timelier indicators of emerging areas of concern. We describe the processes implemented by CDC to operationalize this novel, multifaceted aggregate surveillance system for collecting COVID-19 case and death data to track the spread and impact of the SARS-CoV-2 virus at national, state, and county levels. We also review the processes established to acquire, process, and validate the aggregate number of cases and deaths due to COVID-19 in the United States at the county and jurisdiction levels during the pandemic. These processes include time-saving tools and strategies implemented to collect and validate authoritative COVID-19 case and death data from jurisdictions, such as web scraping to automate data collection and algorithms to identify and correct data anomalies. This topical review highlights the need to prepare for future emergencies, such as novel disease outbreaks, by having an event-agnostic aggregate surveillance system infrastructure in place to supplement line-level case reporting for near-real-time situational awareness and timely data. |
Ultra-long-acting in-situ forming implants with cabotegravir protect female macaques against rectal SHIV infection
Young IC , Massud I , Cottrell ML , Shrivastava R , Maturavongsadit P , Prasher A , Wong-Sam A , Dinh C , Edwards T , Mrotz V , Mitchell J , Seixas JN , Pallerla A , Thorson A , Schauer A , Sykes C , De la Cruz G , Montgomery SA , Kashuba ADM , Heneine W , Dobard CW , Kovarova M , Garcia JV , García-Lerma JG , Benhabbour SR . Nat Commun 2023 14 (1) 708 Ultra-long-acting delivery platforms for HIV pre-exposure prophylaxis (PrEP) may increase adherence and maximize public health benefit. We report on an injectable, biodegradable, and removable in-situ forming implant (ISFI) that is administered subcutaneously and can release the integrase inhibitor cabotegravir (CAB) above protective benchmarks for more than 6 months. CAB ISFIs are well-tolerated in female mice and female macaques showing no signs of toxicity or chronic inflammation. In macaques, median plasma CAB concentrations exceed established PrEP protection benchmarks within 3 weeks and confer complete protection against repeated rectal SHIV challenges. Implant removal via a small incision in 2 macaques at week 12 results in a 7- to 48-fold decrease in plasma CAB levels within 72 hours. Modeling to translate CAB ISFI dosing suggests that a 3 mL injection would exceed protective benchmarks in humans for over 5 months post administration. Our results support the clinical advancement of CAB ISFIs for ultra-long-acting PrEP in humans. |
Pharmacology of boosted and unboosted integrase strand transfer inhibitors for two-dose event-driven HIV prevention regimens among men
Haaland RE , Fountain J , Martin A , Dinh C , Holder A , Edwards TE , Lupo LD , Hall L , Conway-Washington C , Massud I , García-Lerma JG , Kelley CF , Heneine WM . J Antimicrob Chemother 2023 78 (2) 497-503 BACKGROUND: Event-driven HIV prevention strategies are a priority for users who do not require daily pre-exposure prophylaxis (PrEP). Regimens containing integrase strand transfer inhibitors (INSTIs) are under evaluation as alternatives to daily PrEP. To better understand INSTI distribution and inform dosing selection we compared the pharmacology of two-dose boosted elvitegravir and unboosted bictegravir regimens in MSM. MATERIALS AND METHODS: Blood, rectal and penile secretions and rectal biopsies were collected from 63 HIV-negative MSM aged 18-49 years. Specimens were collected up to 96 h after two oral doses of tenofovir alafenamide and emtricitabine with elvitegravir boosted by cobicistat or unboosted bictegravir given 24 h apart. Antiretroviral drugs were measured by LC-MS. RESULTS: Mean bictegravir plasma concentrations remained above the 95% protein-adjusted effective concentration 96 h after dosing [273 (95% CI: 164-456) ng/mL] whereas elvitegravir plasma concentrations became undetectable 48 h after the second dose. Bictegravir and elvitegravir reached rectal tissues within 2 h after the first dose, and elvitegravir tissue concentrations [1.07 (0.38-13.51) ng/mg] were greater than bictegravir concentrations [0.27 (0.15-0.70) ng/mg]. Both INSTIs became undetectable in tissues within 96 h. Elvitegravir and bictegravir were not consistently detected in penile secretions. CONCLUSIONS: Whereas bictegravir plasma concentrations persist at least 4 days after a two-oral-dose HIV prophylaxis regimen, elvitegravir accumulates in mucosal tissues. Differing elvitegravir and bictegravir distribution may result in variable mucosal and systemic antiviral activity and can inform dosing strategies for event-driven HIV prevention. |
Single dose topical inserts containing tenofovir alafenamide fumarate and elvitegravir provide pre- and post-exposure protection against vaginal SHIV infection in macaques
Dobard CW , Peet MM , Nishiura K , Holder A , Dinh C , Mitchell J , Khalil G , Pan Y , Singh ON , McCormick TJ , Agrahari V , Gupta P , Jonnalagadda S , Heneine W , Clark MR , García-Lerma JG , Doncel GF . EBioMedicine 2022 86 104361 BACKGROUND: Vaginal products for HIV prevention that can be used on-demand before or after sex may be a preferable option for women with low frequency or unplanned sexual activity or who prefer not to use daily or long-acting pre-exposure prophylaxis (PrEP). We performed dose ranging pharmacokinetics (PK) and efficacy studies of a vaginally applied insert containing tenofovir alafenamide fumarate (TAF) and elvitegravir (EVG) in macaques under PrEP or post-exposure prophylaxis (PEP) modalities. METHODS: PK studies were performed in 3 groups of pigtailed macaques receiving inserts with different fixed-dose combinations of TAF and EVG (10/8, 20/16 and 40/24 mg). PrEP and PEP efficacy of a selected insert was investigated in a repeat exposure vaginal SHIV transmission model. Inserts were administered 4 h before (n = 6) or after (n = 6) repeated weekly SHIV exposures. Infection outcome was compared with macaques receiving placebo inserts (n = 12). FINDINGS: Dose ranging studies showed rapid and sustained high drug concentrations in vaginal fluids and tissues across insert formulations with minimal dose proportionality. TAF/EVG (20/16 mg) inserts were selected for efficacy evaluation. Five of the 6 animals receiving these inserts 4 h before and 6/6 animals receiving inserts 4 h after SHIV exposure were protected after 13 challenges (p = 0.0088 and 0.0077 compared to placebo, respectively). The calculated PrEP and PEP efficacy was 91.0% (95% CI = 32.2%-98.8%) and 100% (95% CI = undefined), respectively. INTERPRETATION: Inserts containing TAF/EVG provided high protection against vaginal SHIV infection when administered within a 4 h window before or after SHIV exposure. Our results support the clinical development of TAF/EVG inserts for on-demand PrEP and PEP in women. FUNDING: Funded by CDC intramural funds, an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002), and by the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID) under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School. |
Pharmacokinetics and efficacy of topical inserts containing tenofovir alafenamide fumarate and elvitegravir administered rectally in macaques
Makarova N , Singletary T , Peet MM , Mitchell J , Holder A , Dinh C , Agrahari V , Mendoza M , Pan Y , Heneine W , Clark MR , García-Lerma JG , Smith JM , Doncel GF . EBioMedicine 2022 86 104338 BACKGROUND: Topical on-demand forms for HIV pre-exposure prophylaxis (PrEP) may be a desirable alternative for people that prefer not to use daily PrEP. CONRAD has developed inserts containing tenofovir alafenamide (TAF) and elvitegravir (EVG) for on-demand vaginal or rectal pericoital use. We assessed the pharmacokinetics (PK) and pre-exposure efficacy of rectally applied TAF/EVG inserts in macaques. METHODS: PK was assessed in 12 pigtailed macaques. Tenofovir (TFV) and EVG levels were assayed in rectal biopsies and secretions, and tenofovir-diphosphate (TFV-DP) levels in biopsies and peripheral blood mononuclear cells (PBMC). Drug biodistribution was evaluated in 10 animals at necropsy 4 h post-dosing. For efficacy assessments, one or two TAF/EVG inserts were administered to macaques (n = 6) 4 h before repeated rectal SHIV162p3 challenges. FINDINGS: One TAF/EVG insert resulted in rapid and high EVG and TFV-DP in rectal tissue 4 h after application. Adding a second insert led to a 10-fold increase in EVG and TFV-DP in rectal tissue. Efficacy of one and two TAF/EVG inserts were 72.6% (CI 24.5%-92.6%) and 93.1% (CI 73.3%-99.2%), respectively. INTERPRETATION: Although high TFV-DP and EVG levels were observed with one rectal TAF/EVG insert, it only conferred partial protection from rectal SHIV challenges. Adding a second insert led to an increase in TFV and EVG in rectal tissues resulting in higher (>90%) efficacy. These results highlight the high efficacy of TAF/EVG inserts as topical on-demand rectal PrEP, as well as the need for appropriate drug coverage in the deep rectum and colon to achieve high protection. FUNDING: The work related to animal studies was funded by CDC intramural funds and an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002). The work related to the insert formulation was funded by U.S. PEPFAR through USAID under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School. The findings and conclusions of this manuscript are those of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention (CDC), USAID, President's Emergency Plan for AIDS Relief (PEPFAR), Eastern Virginia Medical School (EVMS), or the US government. |
Comparative pharmacokinetics and local tolerance of tenofovir alafenamide (TAF) from subcutaneous implant in rabbits, dogs, and macaques
Gatto GJ , Krovi A , Li L , Massud I , Holder A , Gary J , Mills P , Mitchell J , Luecke E , Demkovich ZR , Heneine W , Garca-Lerma JG , Marzinke MA , Brand RM , Dobard CW , Johnson LM , VanDerStraten A . Front Pharmacol 2022 13 923954 The administration of antiretrovirals (ARVs) for HIV pre-exposure prophylaxis (PrEP) is highly efficacious and may benefit from new long-acting (LA) drug delivery approaches. This paper describes a subcutaneous, reservoir-style implant for the LA delivery of tenofovir alafenamide (TAF) and documents the preclinical assessment of implant safety and pharmacokinetics (PK) in New Zealand White (NZW) rabbits (3 groups of n = 5), beagle dogs (2 groups of n = 6), and rhesus macaques (2 groups of n = 3). Placebo implants were placed in rabbits (n = 10) and dogs (n = 12). Implant parameters, including selection of the TAF form, choice of excipient, and PCL formulation were tuned to achieve targeted concentrations of the active anabolite of TAF, tenofovir diphosphate (TFV-DP), within peripheral blood mononuclear cells (PBMCs) and mucosal tissues relevant to HIV transmission. Sustained concentrations of TFV-DP in PBMCs over 100fmol/10(6) cells were achieved in all animal species indicating that the implants effectively delivered TAF for 3-6months. Unlike placebo implants without TAF, all active implants resulted in local adverse events (AEs) proximal to the implant ranging in severity from mild to moderate and included dermal inflammation and necrosis across all species. Despite these AEs, the implant performed as designed and achieved a constant drug release profile, supporting the continued development of this drug delivery platform. |
Safety and efficacy of a biodegradable implant releasing tenofovir alafenamide for vaginal protection in a macaque model
Massud I , Krovi A , Nishiura K , Ruone S , Li L , Holder A , Gary J , Mills P , Mitchell J , Khalil G , Pan Y , Luecke E , Gatto G , Heneine W , Garcίa-Lerma JG , Johnson L , van der Straten A , Dobard C . J Antimicrob Chemother 2022 77 (11) 2964-2971 OBJECTIVES: To advance the initiative of ending the global epidemic, long-lasting HIV protection is needed through sustained release of antiretroviral drugs for months to years. We investigated in macaques the safety and efficacy of biodegradable polycaprolactone implants releasing tenofovir alafenamide for HIV pre-exposure prophylaxis (PrEP). METHODS: Implants were administered subcutaneously in the arm using a contraceptive trocar. Efficacy against vaginal simian-HIV (SHIV) infection was investigated in six pigtailed macaques that received two tenofovir alafenamide implants (0.35 mg/day), one in each arm, for a total release rate of tenofovir alafenamide at 0.7 mg/day. Macaques were exposed to SHIV twice weekly for 6 weeks. Statistical analyses were used to compare outcome with eight untreated controls. Histological assessments were performed on skin biopsies collected near implantation sites. RESULTS: Median (range) tenofovir diphosphate level in PBMCs was 1519 (1068-1898) fmol/106 cells. All macaques with tenofovir alafenamide implants were protected against vaginal SHIV infection. In contrast, 7/8 controls were infected after a median of 4 SHIV exposures (P = 0.0047). Histological assessment of tissues near tenofovir alafenamide implant sites showed inflammation and necrosis in 5/6 animals, which were not evident by visual inspection. CONCLUSIONS: We demonstrated complete protection against vaginal SHIV infection with two implants releasing a total of 0.7 mg of tenofovir alafenamide per day. We also identified tenofovir diphosphate concentrations in PBMCs associated with complete vaginal protection. Consistent with previous findings, we observed adverse local toxicity and necrosis near the tenofovir alafenamide implant site. Improved tenofovir alafenamide implants that are safe and maintain high efficacy have the potential to provide long-lasting protection against vaginal HIV infection. |
The predictive value of macaque models of preexposure prophylaxis for HIV prevention
García-Lerma JG , McNicholl JM , Heneine W . Curr Opin HIV AIDS 2022 17 (4) 179-185 PURPOSE OF REVIEW: We review macaque models for preexposure prophylaxis (PrEP) for HIV prevention and highlight their role in advancing currently approved and novel PrEP agents. RECENT FINDINGS: The development of the repeat low dose simian HIV (SHIV) challenge models represented a significant advancement in preclinical PrEP modeling that has allowed the investigation of PrEP under conditions that better mimic HIV exposures in humans. These models incorporate relevant drug pharmacology to inform drug correlates of PrEP protection. Models of rectal, vaginal, and penile infection are now available and have been found to predict clinical efficacy of all the currently approved PrEP strategies including daily oral PrEP with the combination of emtricitabine and tenofovir disoproxil fumarate or tenofovir alafenamide, and a long-acting formulation of the integrase inhibitor cabotegravir. These models are being used to test new PrEP modalities including the nucleoside reverse transcriptase-translocation inhibitor islatravir and long-acting capsid inhibitors. The SHIV models have also been supplemented by sexually transmitted infection co-infections with Chlamydia trachomatis, Treponema pallidum or Trichomonas vaginalis to assess the impact of inflammation on PrEP efficacy. SUMMARY: Clinical efficacy validated current PrEP macaque models supporting their continued use to advance novel PrEP agents to improve global PrEP coverage. |
Improving efficiency of COVID-19 aggregate case and death surveillance data transmission for jurisdictions: current and future role of application programming interfaces (APIs).
Khan D , Park M , Lerma S , Soroka S , Gaughan D , Bottichio L , Bray M , Fukushima M , Bregman B , Wiedeman C , Duck W , Dee D , Gundlapalli A , Suthar AB . J Am Med Inform Assoc 2022 29 (10) 1807-1809 During the coronavirus disease-2019 (COVID-19) pandemic, the Centers for Disease Control and Prevention (CDC) supplemented traditional COVID-19 case and death reporting with COVID-19 aggregate case and death surveillance (ACS) to track daily cumulative numbers. Later, as public health jurisdictions (PHJs) revised the historical COVID-19 case and death data due to data reconciliation and updates, CDC devised a manual process to update these records in the ACS dataset for improving the accuracy of COVID-19 case and death data. Automatic data transfer via an application programming interface (API), an intermediary that enables software applications to communicate, reduces the time and effort in transferring data from PHJs to CDC. However, APIs must meet specific content requirements for use by CDC. As of March 2022, CDC has integrated APIs from 3 jurisdictions for COVID-19 ACS. Expanded use of APIs may provide efficiencies for COVID-19 and other emergency response planning efforts as evidenced by this proof-of-concept. In this article, we share the utility of APIs in COVID-19 ACS. |
Genital immune cell activation and tenofovir gel efficacy: a case-control study
Liebenberg LJP , Passmore JS , Osman F , Jewanraj J , Mtshali A , Garcia-Lerma JG , Heneine W , Holder A , Archary D , Ngcapu S , Sivro A , Mansoor LE , Abdool Karim Q , Abdool Karim SS , McKinnon LR . Clin Infect Dis 2022 75 (6) 1088-1091 Genital inflammation (GI) undermines topical HIV pre-exposure prophylaxis (PrEP) efficacy through unknown mechanisms. Here, associations between activated endocervical CD4+ T cell numbers and higher deoxyadenosine triphosphate (dATP) concentrations suggest that competition for intracellular metabolites within HIV target cells may reduce the efficacy of antiretroviral-based PrEP in women with GI. |
Sexually transmitted infections and depot medroxyprogesterone acetate do not impact protection from SHIV acquisition by long-acting cabotegravir in macaques
Vishwanathan SA , Zhao C , Luthra R , Khalil GK , Morris MM , Dinh C , Gary MJ , Mitchell J , Spreen WR , Pereira LE , Heneine W , García-Lerma JG , McNicholl JM . AIDS 2021 36 (2) 169-176 OBJECTIVE: We had previously shown that long-acting cabotegravir (CAB-LA) injections fully protected macaques from vaginal simian HIV (SHIV) infection. Here, we reassessed CAB-LA efficacy in the presence of depot medroxyprogesterone acetate and multiple sexually transmitted infections (STI) that are known to increase HIV susceptibility in women. DESIGN: Two macaque models of increasing vaginal STI severity were used for efficacy assessment. METHODS: The first study (n = 11) used a double STI model that had repeated exposures to two vaginal STI, Chlamydia trachomatis (CT) and Trichomonas vaginalis (TV). Six animals were CAB-LA treated and 5 were controls. The second study (n = 9) included a triple STI model with repeated exposures to CT, TV and syphilis, and the contraceptive, depot medroxyprogesterone acetate (DMPA). Six animals were CAB-LA treated and three were controls. All animals received up to 14 vaginal SHIV challenges. A survival analysis was performed to compare the number of SHIV challenges to infection in the drug-treated group compared to untreated controls over time. RESULTS: All 6 CAB-LA treated animals in both models, the double STI or the triple STI-DMPA model, remained protected after 14 SHIV vaginal challenges while the untreated animals became SHIV-infected after a median of 2 challenges (log-rank p < 0.001) or 1 challenge (log-rank p = 0.002), respectively. Both models recapitulated human STI disease, with vaginal discharge, ulcers and seroconversion. CONCLUSION: In these high and sustained susceptibility models spanning more than 3 months, CAB-LA maintained complete efficacy, demonstrating robustness of the CAB-LA dose used in clinical trials, and suggesting its insensitivity to multiple STIs and DMPA. |
Pharmacokinetics of vaginally applied integrase inhibitors in macaques
Nishiura K , Sharma S , Sterling M , Makarova N , Martin A , Dinh C , Mitchell J , García-Lerma JG , Heneine W , Dobard C . J Antimicrob Chemother 2021 76 (11) 2894-2901 OBJECTIVES: We conducted a detailed pharmacokinetic assessment in macaques treated with vaginal gels formulated with HIV integrase strand transfer inhibitors (INSTIs) to better understand drug distribution and identify INSTI concentrations associated with previously demonstrated in vivo protection against vaginal simian HIV challenge. METHODS: Six macaques received vaginal gel containing 1% raltegravir (30 mg) once-weekly over 6 weeks. Following a washout period, five macaques received once-weekly gel containing 0.23% L-870,812 (7 mg). Drug concentrations were measured in plasma, mucosal fluids and vaginal tissues at baseline and 2, 5 and 24 h post-dosing. RESULTS: The median maximum concentration (Cmax) for raltegravir and L-870,812 in plasma was below the limit of quantification and 41.1 ng/mL, respectively. The Cmax in vaginal fluids (1441 and 1250 μg/mL) and tissues (266.7 and 368.4 μg/g) was achieved 2-5 h after dosing, respectively. A similar half-life was observed for raltegravir and L-870,812 in vaginal fluids (8-10 h) and remained 3-4 orders of magnitude above the protein-adjusted IC95 (0.016 and 0.106 μg/mL, respectively) at 24 h. Drug concentrations in vaginal fluids correlated well with those in vaginal tissues (Pearson r ≥ 0.788). Both drugs were consistently detected in rectal fluids 2 h after vaginal dosing, albeit at much lower levels (31-92-fold) than those in vaginal fluids. CONCLUSIONS: To the best of our knowledge, this study provides the first data on INSTI levels in vaginal tissues associated with in vivo protection and demonstrates rectal drug distribution of INSTIs after vaginal dosing. These findings may inform dose selection for topical products with INSTIs for HIV prevention. |
Proinflammatory oscillations over the menstrual cycle drives bystander CD4 T cell recruitment and SHIV susceptibility from vaginal challenge
Swaims-Kohlmeier A , Sheth AN , Brody J , Hardnett FP , Sharma S , Bonning EW , Ofotokun I , Massud I , García-Lerma JG . EBioMedicine 2021 69 103472 BACKGROUND: The menstrual cycle influences HIV infection-risk in women, although the timing and underlying mechanism are unclear. Here we investigated the contribution of the menstrual cycle to HIV susceptibility through evaluating immune behavior with infection-risk over time. METHODS: Blood and vaginal lavage samples were collected from 18 pig-tailed macaques to evaluate immune changes over reproductive cycles, and from 5 additional animals undergoing repeated vaginal exposures to simian HIV (SHIV). Peripheral blood mononuclear cell (PBMC) samples from healthy women (n = 10) were prospectively collected over the course of a menstrual cycle to profile T cell populations. Immune properties from PBMC and vaginal lavage samples were measured by flow cytometry. Plasma progesterone was measured by enzyme immunoassay. The oscillation frequency of progesterone concentration and CCR5 expression on CD4 T cells was calculated using the Lomb-Scargle periodogram. SHIV infection was monitored in plasma by RT-PCR. Immune measures were compared using generalized estimating equations (GEE). FINDINGS: Macaques cycle-phases were associated with fluctuations in systemic immune properties and a type-1 inflammatory T cell response with corresponding CCR5+ memory CD4 T cell (HIV target cell) infiltration into the vaginal lumen at the late luteal phase. Power spectral analysis identified CCR5 oscillation frequencies synchronized with reproductive cycles. In a repetitive low-dose vaginal challenge model, productive SHIV(163P3) infection only occurred during intervals of mounting type-1 T cell responses (n = 5/5). Finally, we identify similar type-1 inflammatory T cell responses over the menstrual cycle are occurring in healthy women. INTERPRETATION: These data demonstrate that periodic shifts in the immune landscape under menstrual cycle regulation drives bystander CCR5+ CD4 T cell recruitment and HIV susceptibility in the female reproductive tract. FUNDING: This study was supported by the U.S. Centers for Disease Control and Prevention, Atlanta, GA 30329 and NIH grants to Emory University (K23AI114407 to A.N.S., the Emory University Center for AIDS research [P30AI050409], and Atlanta Clinical and Translational Sciences Institute [KLR2TR000455, UL1TR000454]). DISCLAIMER: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the U.S. Centers for Disease Control and Prevention or the Department of Health and Human Services. |
Antiretroviral drug exposure in urethral and glans surface sampling of the penis
Haaland RE , Fountain J , Dinh C , Lupo LD , Martin A , Conway-Washington C , Hall L , Kelley CF , Garcia-Lerma JG , Heneine W . J Antimicrob Chemother 2021 76 (9) 2368-2374 BACKGROUND: HIV exposure to penile tissues provides a risk of acquisition among men, yet studies evaluating penile antiretroviral (ARV) drug distribution have been lacking. We measured ARVs on urethral and glans surface swabs collected following a dose of tenofovir alafenamide, emtricitabine, elvitegravir, darunavir and cobicistat. METHODS: Thirty-five HIV-negative male participants provided urethral swabs, glans swabs, rectal swabs, blood and urine up to 96 h following a single dose of tenofovir alafenamide/emtricitabine/elvitegravir/cobicistat and darunavir. ARVs were measured by liquid chromatography-mass spectrometry with a lower limit of detection (LOD) of 1 ng/swab for swabs and 10 ng/mL for plasma and urine. Concentrations are reported as median and range. RESULTS: Urethral swab emtricitabine and darunavir concentrations peaked at 4 h for emtricitabine (36 ng/swab; 3-307 ng/swab) and 8 h for darunavir (25 ng/swab; 2-52 ng/swab). Glans swab emtricitabine and darunavir concentrations peaked 24 h after dosing (emtricitabine 14 ng/swab, <LOD-328 ng/swab; darunavir 6 ng/swab, <LOD-149 ng/swab). Estimated peak urethral secretion emtricitabine and darunavir concentrations are between 10 and 20 μg/mL, similar to rectal secretions, 4-fold greater than in plasma, but 2-fold lower than in urine. Tenofovir and elvitegravir were detected on less than 20% of urethral or glans swabs collected within 24 h of dosing. CONCLUSIONS: We document ARV dosing in the urethra and on the glans surface with high drug concentrations noted for emtricitabine and darunavir and lower tenofovir and elvitegravir concentrations. Data suggest a potential protective role of urethral emtricitabine or darunavir against penile HIV acquisition. |
Tenofovir Alafenamide (TAF) for HIV Prevention: Review of the Proceedings from the Gates Foundation Long Acting (LA) TAF Product Development Meeting
Romano JW , Baum M , Demkovich ZR , Diana F , Dobard C , Feldman PL , Garcia-Lerma JG , Grattoni A , Gunawardana M , Ho DK , Hope TJ , Massud I , Milad M , Moss J , Pons-Faudoa FP , Roller S , van der Straten A , Srinivasan S , Veazey R , Zane D . AIDS Res Hum Retroviruses 2021 37 (6) 409-420 The ability to successfully develop a safe and effective vaccine for the prevention of HIV infection has proven challenging. Consequently, alternative approaches to HIV infection prevention have been pursued, and there have been a number of successes with differing levels of efficacy. Currently, only two oral pre-exposure prophylaxis (PrEP) products are available, Truvada and Descovy. Descovy is a newer product not yet indicated in individuals at risk of HIV-1 infection from receptive vaginal sex, since it still needs to be evaluated in this population. A topical dapivirine vaginal ring is currently under regulatory review, and a long acting (LA) injectable cabotegravir product shows strong promise. Although demonstrably effective, daily oral PrEP presents adherence challenges for many users, particularly adolescent girls and young women, key target populations. This limitation has triggered development efforts in LA HIV prevention options. This article reviews efforts supported by the Bill & Melinda Gates Foundation, as well as similar work by other groups, to identify and develop optimal LA HIV prevention products. Specifically, this article is a summary review of a meeting convened by the foundation in early 2020 that focused on the development of LA products designed for extended delivery of tenofovir alafenamide (TAF) for HIV prevention. The review broadly serves as technical guidance for preclinical development of LA HIV prevention products. The meeting examined the technical feasibility of multiple delivery technologies, in vivo pharmacokinetics, and safety of subcutaneous delivery of TAF in animal models. Ultimately, the foundation concluded that there are technologies available for long-term delivery of TAF. However, due to potentially limited efficacy and possible toxicity issues with subcutaneous (SC) delivery, the foundation will not continue investing in the development of LA, SC delivery of TAF products for HIV prevention. |
The effect of depot medroxyprogesterone acetate on tenofovir alafenamide in rhesus macaques
Daly MB , Sterling M , Holder A , Dinh C , Nishiura K , Khalil G , García-Lerma JG , Dobard C . Antiviral Res 2020 186 105001 Prevention of HIV infection and unintended pregnancies are public health priorities. In sub-Saharan Africa, where HIV prevalence is highest, depot-medroxyprogesterone acetate (DMPA) is widely used as contraception. Therefore, understanding potential interactions between DMPA and antiretrovirals is critical. Here, we use a macaque model to investigate the effect of DMPA on the pharmacology of the antiretroviral tenofovir alafenamide (TAF). Female rhesus macaques received 30 mg of DMPA (n=9) or were untreated (n=9). Macaques received a human equivalent dose of TAF (1.5 mg/kg) orally by gavage. Tenofovir (TFV) and TFV-diphosphate (TFV-DP) were measured in blood, secretions, and tissues over 72 hours. The median area under the curve (AUC(0-72h)) values for TFV-DP in peripheral blood mononuclear cells were similar in DMPA-treated (6,991 fmol*h/10(6) cells) and untreated controls (5,256 fmol*h/10(6) cells) (P=0.174). Rectal tissue TFV-DP concentrations from DMPA+ animals [median: 20.23 fmol/mg of tissue (range: 4.94-107.95)] were higher than the DMPA-group [median: below the limit of quantification (BLOQ-11.92)], (P=0.019). TFV-DP was not detectable in vaginal tissue from either group. A high-dose DMPA treatment in macaques was associated with increased rectal TFV-DP levels, indicating a potential tissue-specific drug-drug interaction. The lack of detectable TFV-DP in the vaginal tissue warrants further investigation of PrEP efficacy with single-agent TAF products. DMPA did not affect systemic TAF metabolism, with similar PBMC TFV-DP in both groups, suggesting that DMPA use should not alter the antiviral activity of TAF. |
Altered antibody responses in persons infected with HIV-1 while using PrEP
Parker I , Khalil G , Martin A , Martin MT , Vanichseni S , Leelawiwat W , McNicholl JM , Hickey A , Garcia-Lerma JG , Choopanya K , Curtis K . AIDS Res Hum Retroviruses 2020 37 (3) 189-195 BACKGROUND: Pre-exposure prophylaxis (PrEP) is an effective HIV prevention tool, although effectiveness is dependent upon adherence. It is important to characterize the impact of PrEP on HIV antibody responses in people who experience breakthrough infections in order to understand the potential impact on timely diagnosis and treatment. METHODS: Longitudinal HIV-1-specific antibody responses were evaluated in 42 people who inject drugs (PWID) from the Bangkok Tenofovir Study (placebo=28; PrEP=14) who acquired HIV while receiving PrEP. HIV-1 antibody levels and avidity to three envelope proteins (gp41, gp160, and gp120) were measured in the plasma using a customized Bio-Plex (Bio-Rad Laboratories) assay. A survival analysis was performed for each biomarker to compare the distribution of times at which study subjects exceeded the recent/long-term assay threshold, comparing PrEP and placebo treatment groups. We fit mixed-effects models to identify longitudinal differences in antibody levels and avidity between groups. RESULTS: Overall, longitudinal antibody levels and avidity were notably lower in the PrEP breakthrough group compared to the placebo group. Survival analyses demonstrated a difference in time to antibody reactivity between treatment groups for all Bio-Plex biomarkers. Longitudinal gp120 antibody levels within the PrEP breakthrough group were decreased compared to the placebo group. When accounting for PrEP adherence, both gp120 and gp160 antibody levels were lower in the PrEP breakthrough group compared to the placebo group. CONCLUSION: We demonstrate hindered envelope antibody maturation in PWID who became infected while receiving PrEP in the Bangkok Tenofovir Study, which has significant implications for HIV diagnosis. Delayed maturation of the antibody response to HIV may increase the time to detection for antibody-based tests. |
Editorial: Pharmacokinetics and pharmacodynamics of pre-exposure prophylaxis against HIV
von Kleist M , García-Lerma JG , Liu A , Anderson PL . Front Pharmacol 2020 11 1288 In 2018 about 1.7 million individuals became infected with the human immunodeficiency virus (HIV)1. While therapies are highly effective in suppressing virus replication and reducing transmission, viral rebound generally occurs within weeks after treatment discontinuation (Chun et al., 2015). The establishment of a latent virus reservoir early in infection poses challenges for identifying effective HIV cure strategies. Vaccines have had limited success to date (Rerks-Ngarm et al., 2009; Caskey et al., 2019) although some promising strategies are under evaluation. While a major success in HIV research has been the development of highly effective antiretrovirals, a fruitful idea is to re-purpose those drugs for HIV prevention. Substantial progress has been made developing antiretroviral (ARV)-based strategies to prevent HIV transmission, including pre-exposure prophylaxis (PrEP) (Grant et al., 2010). PrEP with oral FTC in combination with tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF) is an established prevention strategy to protect certain populations at risk of HIV acquisition. |
Single oral dose for HIV pre or post-exposure prophylaxis: user desirability and biological efficacy in macaques
Massud I , Ruone S , Zlotorzynska M , Haaland R , Mills P , Cong ME , Kelley K , Johnson R , Holder A , Dinh C , Khalil G , Pan Y , Kelley CF , Sanchez T , Heneine W , Garcia-Lerma JG . EBioMedicine 2020 58 102894 BACKGROUND: Daily oral pre- or post-exposure prophylaxis (PrEP or PEP) is highly effective in preventing HIV infection. However, many people find it challenging to adhere to a daily oral regimen. Chemoprophylaxis with single oral doses of antiretroviral drugs taken before or after sex may better adapt to changing or unanticipated sexual practices and be a desirable alternative to daily PrEP or PEP. We investigated willingness to use a single oral pill before or after sex among men who have sex with men (MSM) and assessed the biological efficacy of a potent antiretroviral combination containing elvitegravir (EVG), emtricitabine (FTC), and tenofovir alafenamide (TAF). METHODS: Data on willingness to use single-dose PrEP or PEP were obtained from the 2017 cycle of the American Men's Internet Survey (AMIS), an annual online behavioral surveillance survey of MSM in the United States. Antiretroviral drug levels were measured in humans and macaques to define drug distribution in rectal tissue and identify clinically relevant doses for macaque modeling studies. The biological efficacy of a single dose of FTC/TAF/EVG as PrEP or PEP was investigated using a repeat-challenge macaque model of rectal HIV infection. FINDINGS: Through pharmacokinetic assessment in humans and macaques we found that EVG penetrates and concentrates in rectal tissues supporting its addition to FTC/TAF to boost and extend chemoprophylactic activity. Efficacy estimates for a single oral dose given to macaques 4h before or 2h after SHIV exposure was 91•7%[35•7%-98•9%] and 100%, respectively, compared to 80•1%[13•9%-95•4%] and 64•6%[-19•4%-89•5%] when single doses were given 6 and 24h post challenge, respectively. A two-dose regimen at 24h and 48h after exposure was also protective [77•1%[1•7%-94•7%]. INTERPRETATION: Informed by user willingness, human and macaque pharmacokinetic data, and preclinical efficacy we show that single-dose prophylaxis before or after sex is a promising HIV prevention strategy. Carefully designed clinical trials are needed to determine if any of these strategies will be effective in humans. FUNDING: Funded by CDC intramural funds, CDC contract HCVJCG2-2016-03948 (to CFK), and a grant from the MAC AIDS Fund and by the National Institutes of Health [P30AI050409] - the Emory Center for AIDS Research (to MZ and TS). |
Cabotegravir long-acting protects macaques against repeated penile SHIV exposures
Dobard C , Makarova N , Nishiura K , Dinh C , Holder A , Sterling M , Lipscomb J , Mitchell J , Deyounks F , Garber D , Khalil G , Spreen W , Heneine W , Garcia-Lerma JG . J Infect Dis 2020 222 (3) 391-395 We used a novel penile simian HIV (SHIV) transmission model to investigate if cabotegravir long-acting (CAB LA) prevents penile SHIV acquisition in macaques. Twenty-two macaques were exposed to SHIV via the foreskin and urethra once-weekly for 12 weeks. Of these, six received human-equivalent doses of CAB LA, six received oral FTC/TDF, and 10 were untreated. The efficacy of CAB LA was high (94.4% [95%CI=58.2%-99.3%]) and similar to that seen with oral FTC/TDF (94.0% [95%CI=55.1%-99.2%]). The high efficacy of CAB LA in the penile transmission model supports extending the clinical advancement of CAB LA PrEP to heterosexual men. |
Training rhesus macaques to take daily oral antiretroviral therapy for preclinical evaluation of HIV prevention and treatment strategies
Daly MB , Clayton AM , Ruone S , Mitchell J , Dinh C , Holder A , Jolly J , Garcia-Lerma JG , Weed JL . PLoS One 2019 14 (11) e0225146 BACKGROUND: Macaque models of simian or simian/human immunodeficiency virus (SIV or SHIV) infection are critical for the evaluation of antiretroviral (ARV)-based HIV treatment and prevention strategies. However, modelling human oral ARV administration is logistically challenging and fraught by limited adherence. Here, we developed a protocol for administering daily oral doses of ARVs to macaques with a high rate of compliance. METHODS: Parameters of positive reinforcement training (PRT), behavioral responses and optimal drug delivery foods were defined in 7 male rhesus macaques (Macaca mulatta). Animals were trained to sit in a specified cage location prior to receiving ARVs, emtricitabine (FTC) and tenofovir alafenamide (TAF), in a blended food mixture, which was followed immediately with a juice chaser. Consistency of daily oral adherence was evaluated in 4 trained macaques receiving clinically equivalent doses of FTC and TAF (20 and 1.5 mg/kg, respectively) in a short-term (1 month) and an extended (6 month) trial. Adherence was monitored using medication diaries and by quantifying intracellular FTC-triphosphate (FTC-TP) and tenofovir-diphosphate (TFV-DP) concentrations in peripheral mononuclear blood cells (PBMCs). RESULTS: Trained macaques quickly and consistently took daily oral ARVs for 1 month with an average 99.8% observed adherence. Intracellular concentrations of TFV-DP (median = 845.8 fmol/million cells [range, 620.8-1031.3]) and FTC-TP (median = 367.0 fmol/million cells [range, 289.5-413.5) in PBMCs were consistent with high adherence. Extended treatment with select subjects yielded similar observations for three months (99.5% adherence, 352/356 complete doses taken), although a sudden drop in adherence was observed after splenic biopsy surgery. CONCLUSIONS: We demonstrate that trained macaques reliably adhere to a daily oral ARV regimen, although unexpected adherence issues are possible. Our approach, using clinical doses of oral FTC and TAF daily, further refines macaque models of HIV treatment and prevention by mimicking the human route and timing of ARV administration. |
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