CROI 2019 Abstract eBook

Abstract eBook

Poster Abstracts

(TFV-DP) concentrations in vivo. Here, we examined the influence of TFV-mE and TFV on intracellular TFV-DP concentrations in peripheral blood mononuclear cells (PBMC) and dried blood spots (DBS) in HIV-uninfected adults. Methods: Samples were obtained from a randomized, crossover bioequivalence study of single-dose TDF/emtricitabine unencapsulated or co-encapsulated with the Proteus® Ingestible Sensor. Visits were separated by a 14-day washout. Blood for PK assessments were collected serially through 72 hours post-dose, and PBMC and DBS were isolated at 24 hours post-dose at both visits. TFV-mE and TFV were quantified via LC/MS-MS. Area under the concentration-time curve extrapolated to infinity (AUC) of plasma TFV-mE and TFV were calculated via noncompartmental methods (Phoenix WinNonlin v8.0). A mixed-effects model was used to examine TFV-mE AUC, TFV AUC, visit, randomization sequence, formulation, sex, BMI, and eGFR as fixed effects and subjects as random effects, with TFV-DP in DBS or PBMC as primary outcomes (SAS Enterprise v9.4). Results: Samples were available from 24 participants (48 observations). Geometric mean (%CV) for TFV-mE and TFV AUC were 93.9 (46.8%) and 1986.0 (26.9%) h*ng/mL. Visit 1 TFV-DP was 45.3 (48.2%) fmol/punch in DBS and 10.8 (42.4%) fmol/10^6 cells in PBMCs. Visit was a significant predictor of TFV-DP in DBS, but not PBMC, with 95.1% higher concentrations at visit 2 ([95% CI 59.2%, 139.0%]; p<0.0001) (Table), consistent with the ~17-day half-life for TFV-DP in DBS. TFV-mE AUC was a significant predictor of TFV-DP in both PBMC and DBS. For every 10 h*ng/mL increase in TFV-mE AUC, TFV-DP concentrations increased by 3.8% ([95% CI 0.8%,6.8%]; p=0.015) in PBMCs and 4.3% ([95% CI 1.5%,7.2%]; p=0.005) in DBS, the latter of which was controlled for study visit. Conversely, TFV AUC was not significantly associated with TFV-DP concentrations in PBMCs (p=0.11) or DBS (p>0.99). Randomization sequence, formulation, and other clinical variables did not significantly influence TFV-DP in either cell type. Conclusion: Plasma TFV-mE AUC was a significant predictor of intracellular TFV-DP concentrations in PBMC and DBS, whereas plasma TFV AUC was not. TFV-mE contributes to cell loading in vivo, influencing TFV-DP concentrations in PBMC and DBS. 478 DEPO-MEDROXYPROGESTERONE EFFECTS ON TENOFOVIR-DP AND LAMIVUDINE-TP IN CERVICAL TISSUE Melanie Nicol 1 , Prosperity Eneh 1 , Rita Nakalega 2 , Samuel Kabwigu 2 , Esther Isingel 2 , Noah Kiwanuka 3 , Mags Beksinska 4 , Craig Sykes 5 , Mary G. Fowler 6 , Todd T. Brown 6 , Flavia K. Matovu 2 1 University of Minnesota, Minneapolis, MN, USA, 2 Makerere University–Johns Hopkins University Research Collaboration, Kampala, Uganda, 3 Makerere University College of Health Sciences, Kampala, Uganda, 4 MatCH, Durban, South Africa, 5 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 6 Johns Hopkins University, Baltimore, MD, USA Background: Effective concentrations of antiretrovirals in the female genital tract (FGT) are critical for suppression of viral shedding, or, in the case of pre- exposure prophylaxis, HIV prevention. The disposition of tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) in the FGT have been previously described. However, despite widespread lamivudine use, lamivudine triphosphate (3TC-TP) exposure in FGT is unknown. Furthermore, to facilitate development of multipurpose prevention for contraception and HIV, a better understanding of exogenous hormone effect on FGT antiretroviral exposure is needed. Methods: HIV-positive, virologically suppressed, non-pregnant women, receiving combination TDF/3TC as part of antiretroviral therapy, were recruited in Kampala, Uganda. Women receiving depot-medroxyprogesterone (DMPA group) or using non-hormonal contraception (non-HC group) participated in a single visit study . Cervical biopsies were obtained for quantification of TFV-DP, 3TC-TP, and endogenous dATP and dCTP using liquid chromatography with

tandemmass spectrometry. Blood plasma was collected to assess medication adherence. Differences between groups were tested using multiple linear regression on log-transformed data and adjusted for age, weight, and plasma drug concentrations (for tissue) or time since last dose (for plasma). Results: Fifty women aged 21-34 years were enrolled between Nov 2017 and March 2018. One subject in the DMPA group and two in the non-HC group were excluded from antiretroviral quantification as plasma concentrations were indicative of non-adherence. One additional biopsy in DMPA group was excluded due to sample processing error. Unadjusted medians (25th, 75th percentile) are reported in attached table. Concentrations of 3TC-TP were significantly higher than TFV-DP in cervical tissues with a geometric mean ratio of 17.3. Cervical TFV-DP was 64% higher in DMPA users compared to non-HC users (p=0.02). No differences were found between groups for TFV or 3TC in plasma, or in 3TC-TP, dATP, dCTP in cervical tissues. Conclusion: These data provide the first information on drug exposure of 3TC-TP in the FGT following oral dosing. Similar to reports of FTC-TP, 3TC-TP was significantly higher than TFV-DP in cervical tissue, suggesting it may be an option for prophylaxis. TFV-DP was significantly higher in DMPA users compared to women using non-hormonal contraception, suggesting prevention efficacy is unlikely to be compromised by injectable progestin contraceptive use.

Poster Abstracts

479 A QUANTITATIVE APPROACH TO EVALUATE ARV PROXIMITY TO VIRUS AND CELLS IN LYMPH NODES Elias Rosen 1 , Claire Deleage 2 , Yuri Fedoriw 1 , Jacob D. Estes 3 , Angela Kashuba 1 1 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 2 Frederick National Laboratory for Cancer Research, Frederick, MD, USA, 3 Oregon Health and Sciences University, Portland, OR, USA Background: We have previously shown that ARV distribution within lymphoid tissue can be highly heterogeneous. Understanding potential consequences of diverse ARV accumulation requires quantitative methods to characterize ARV proximity to virus and target cells. Here, we developed a novel analytical approach based on a combination of mass spectrometry imaging (MSI), in situ hybridization (ISH) and immunohistochemistry (IHC) to understand the consequences of ARV distribution in lymph nodes (LN). Methods: Axillary LN were collected and snap frozen at necropsy from RT-SHIV infected rhesus macaques dosed 10 days with emtricitabine (FTC) + tenofovir (TFV) (N=6) in combination with either efavirenz (EFV) + raltegravir (RAL) (N=3), cohort FTER, or maraviroc (MVC) + atazanavir (ATZ) (N=3), cohort FTMA. Tissue accumulation of ARVs and metabolites was measured by infrared matrix- assisted laser desorption electrospray ionization (IR-MALDESI) MSI from 10 mm thick cryosections at 0.1 mm spatial resolution. Serial sections of tissue were analyzed for viral RNA (vRNA) by RNAscope ISH and for CD4+ cells by IHC. Spatial relationships were evaluated by nearest neighbor search (NNS) on co-registered images using MATLAB (Fig A). Results: MSI simultaneously measured all detectable ARVs (FTC, RAL < limits of detection: 0.05-0.37 ng/mg tissue) and the blood biomarker, HEME. Based on NNS analysis between ARVs and HEME (reflecting ARV in the vasculature), 57% of all ARVs in LN were ≤0.1 mm from HEME. The greatest tissue penetration was

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