CROI 2016 Abstract eBook

Abstract Listing

Poster Abstracts

876 CVLs FromWomen Vaginally DosedWith PC-1005 Inhibit Mucosal HIV-1 and HSV-2 Ex Vivo Guillermo Villegas 1 ; Shimin Zhang 1 ; Olga Mizenina 1 ; Kyle Kleinbeck 1 ; Michael Cooney 1 ; Craig Hoesley 2 ; George Creasy 1 ; José Fernández-Romero 1 ;Thomas Zydowsky 1 ; Natalia Teleshova 1 1 Pop Council, New York, NY, USA; 2 Univ of Alabama at Birmingham, Birmingham, AL, USA Background: A recent Phase 1 trial demonstrated that PC-1005 gel containing 50µMMIV-150, 14mM zinc acetate dihydrate and carrageenan (CG) applied daily vaginally for up to 14 days is safe and well tolerated. Additionally, cervico-vaginal lavage samples (CVLs) collected 4h or 24h after last gel application showed MIV-150 and CG dose-dependent inhibition of HIV-1 and HPV in cell-based assays (Friedland et al, in preparation). We aimed to determine anti-HIV and anti-HSV-2 activity of CVLs in human ectocervical explants ex vivo . Methods: CVLs collected at the baseline and 4h (n=6 PC-1005 and n=2 hydroxycellulose (HEC) placebo) or 24h (n=6 PC-1005 and n=1 HEC placebo) post last vaginal gel administration during Phase 1 trial were utilized. CG and MIV-150 concentrations in CVLs were measured by ELISA and LC-MS/MS, respectively. Human ectocervical explants were prepared from tissues received from National Disease Research Interchange. Explants (n=3 per condition) were incubated with CVLs (1:1) for 4h, washed with PBS and then challenged with 500 TCID 50 HIV-1 BaL or co-challenged with 500 TCID 50 HIV-1 BaL and 10 6 pfu HSV-2 per explant for ~18h, washed and then cultured for 14d. The activity of each baseline and corresponding post-gel exposure CVL was tested in tissues from the same donor. To determine contribution of CG to anti-HIV activity of CVLs, tissues were challenged with HIV-1 Bal after exposure to baseline CVLs spiked with CG concentrations detected in the study (n=3 experiments). Infections were monitored by one step HIV gag RT-qPCR and HSV-2 pol q PCR on culture supernatants (individual replicate analysis). SOFT and CUM endpoint analyses were performed. Tissue viability post exposure to CVLs was tested using MTT assay. Log-normal generalized linear mixed models were used for statistical analysis. Results: MIV-150 and CG in CVLs inhibited HIV and HSV-2 infection (single HIV challenge or co-challenge with HSV-2) in the explants in a dose-dependent manner (p≤0.01), with stronger inhibition using CVLs collected 4h post last gel administration. CG concentrations (>250 µg/ml; n=4 CVLs) could have contributed to the observed anti-HIV activity based on >55% HIV-1 Bal infection inhibition in the CG spiking experiments. Conclusions: The anti-HIV and anti-HSV-2 activity of CVLs in human ectocervical explants warrants the further development of PC-1005 gel as a broad-spectrum on demand microbicide. 877 Transport of Drug and Virus in FRTs of Macaques TreatedWith a TDF Intravaginal Ring Background: Prevention of HIV transmission using a tenofovir disoproxil fumarate (TDF)-eluting intravaginal ring (IVR) is a complex and poorly understood interplay between transport of drug and virus throughout and within the tissues of the female reproductive tract (FRT). Sufficiently high drug levels must be achieved both throughout and within the tissues of the entire FRT to prevent viral infection. This work demonstrates that not only is virus capable of infecting the ovaries, but that an IVR is also sometimes capable of achieving low drug concentrations there as well, highlighting the complexity of transport within the FRT and the need for further experiments and modeling. Methods: Three pigtail macaques were treated with TDF-IVRs for 28 days, and vaginally challenged with a high dose of a replicative SIVmac239 virus and a single round non- replicative SIV-based vector expressing Luciferase and mCherry reporter genes. In order to identify infection events the isolated FRT was treated with luciferin to detect Luciferase activity using IVIS. TFV and TFV-DP concentrations in tissue were quantified using LC-MS/MS, with 13C-labeled TFV used as an internal standard. Results: Infection events were detected in both ovaries in two animals and in one ovary of the third macaque using IVIS. TFV levels were found to be variable throughout the FRT, with the highest concentrations found in the upper vagina/lower cervical area, near the site of the ring. The concentration of TFV in the FRT of the macaques were in the range of 40-28,000 fmol/mg of tissue and the concentration of TFV-DP in the FRT of the macaques were in the range of 3-6000 fmol/mg of tissue. Conclusions: Infection events were seen in the ovaries of all three macaques, possibly reflecting the variability of ovarian drug levels (range of 7-30 fmol TFV-DP/mg of tissue) and virus transport. 878 Impact of STI on Pharmacokinetics of Topical Tenofovir in Macaques Natalia Makarova ; Rachael Aubert; Angela Holder; Chuong Dinh;Tara Henning; Ellen Kersh; Janet McNicholl;Walid Heneine; Charles Dobard CDC, Atlanta, GA, USA Background: Genital tract inflammation associated with sexually transmitted infections (STIs) can increase HIV risk and potentially reduce the efficacy of topically delivered tenofovir (TFV). We previously showed that co-infection of macaques with Chlamydia trachomatis ( CT ) and Trichomonas vaginalis ( TV ) increases SHIV infection risk by 2.5-fold but has little effect on the efficacy of a 1% TFV gel applied vaginally 30 minutes (100% efficacy) or 3 days (64% efficacy) before SHIV exposure. Here, we investigate the effect of CT/TV co-infection on systemic drug absorption from 1% TFV gel and on TFV diphosphate (TFV-DP) concentrations in vaginal lymphocytes. Methods: Pigtailed macaques with regular menstrual cycles were co-infected with CT/TV and treated with 1% TFV gel vaginally once (n=6) or twice (n=6) per week for up to 2 complete menstrual cycles (10 weeks). Plasma TFV levels were measured 30 minutes after gel application and were compared to those seen in STI-naïve macaques that received the same gel formulation under the same dosing conditions. Cumulative TFV plasma exposure over a 28-day cycle was expressed as area under the curve 28 day (AUC 28d ). Intracellular TFV-DP concentrations were quantified in vaginal biopsies collected from 2 STI-infected and 2 uninfected macaques 2h after gel application. We also measured values that were ~2.7 times as high in STI-infected animals compared to uninfected macaques (1,877 and 685 ng*d/ml, respectively; p = 0.02 Wilcoxon rank test). Median TFV-DP levels in vaginal biopsies collected 2 h after dosing were also higher in STI-infected [1,733 fmol/mg (range 152-8,277)] compared to uninfected [162 fmol/mg (range 43-648)] animals. Likewise, TFV-DP levels measured in vaginal lymphocytes at 3 days were higher in STI-infected [1,093 fmol/10 6 cells, range = 12 - 2,336] than in uninfected macaques (158 fmol/10 6 cells, range = 27-259)]. Conclusions: We demonstrate increased vaginal absorption of TFV in the setting of STI co-infections, which may reflect increased tissue drug permeability. Both the modest 2.5-fold increase in susceptibility to SHIV by STIs and higher TFV-DP concentrations in vaginal tissue and lymphocytes likely explain the protection seen in macaques co-infected with STIs. 879 A Long-Acting Biodegradable Subcutaneous Implant for Tenofovir HIV PrEP Erica B. Schlesinger 1 ; Daniel Johengen 1 ; Ellen Leucke 2 ; Stephanie Swarner 3 ; Phillip Durham 3 ; Leah Johnson 3 ; Ginger Rothrock 3 ; Ian McGowan 4 ; Ariane van der Straten 2 ;Tejal Desai 1 1 Univ of California San Francisco, San Francisco, CA, USA; 2 RTI, San Francisco, CA, USA; 3 RTI, Research Triangle Park, NC, USA; 4 Univ of Pittsburgh Sch of Med, Pittsburgh, PA, USA Background: Antiretroviral (ARV) effectiveness for HIV pre-exposure prophylaxis (PrEP) is proven, but hinges on correct and consistent use. User compliance and therapeutic effectiveness can be improved by long acting drug delivery systems. Here we describe a thin-film polymer device (TFPD) as a biodegradable subcutaneous implant for PrEP. A thin-film polycaprolactone (PCL) membrane controls drug release from a reservoir, and release rates and device size are tunable, a key feature for an implant in the early stages of pre-clinical development. We have explored release of ARVs from various classes and will present data pertaining to development of a device to deliver Tenofovir Alafenimide Fumarate (TAF). Methods: Devices were fabricated as a hollow rod with an open end using a wire-heat sealing apparatus and solvent cast PCL films. TAF was loaded into the reservoir with or without formulation excipients. Devices were sealed and incubated in PBS, pH7.4 at 37˚C. For release rates we measured TAF concentration in release media over time. Sink TFV-DP levels in vaginal lymphocytes collected 3 days after gel dosing in 4 STI-infected and 4 uninfected macaques. Results: Co-infection with CT/TV increased plasma TFV concentrations over all phases of the menstrual cycle with AUC 28d Adina K. Ott 1 ; Katarina K. Halavaty 1 ; Jonathan Su 1 ; Danijela Maric 1 ; Samuel Sung 1 ; Mark A. Marzinke 2 ;Tom J. Hope 3 ; Patrick Kiser 1 1 Northwestern Univ, Chicago, IL, USA; 2 Johns Hopkins Univ, Baltimore, MD, USA; 3 Northwestern Univ, Feinberg Sch of Med, Chicago, IL, USA

Poster Abstracts

369

CROI 2016