CROI 2015 Program and Abstracts

Abstract Listing

Poster Abstracts

542 Dual Loaded Sustained Release Core-Shell Nanoparticles for Anti-HIV Therapy Hilliard L. Kutscher 1 ; Jessica L. Reynolds 1 ; Faithful Makita 2 ; Sara DiTursi 1 ; Jacob Milling 1 ; Jesse Hanchett 1 ; Charles C. Maponga 2 ; Paras N. Prasad 1 ; Gene D. Morse 1 1 University at Buffalo, Buffalo, NY, US; 2 University of Zimbabwe, College of Health Sciences, Harare, Zimbabwe

Background: Human immunodeficiency virus (HIV) is the world’s deadliest infectious disease and progressively suppresses the immune system leading to mortality. Due to length of treatment, high pill burden and adverse effects, patient non-adherence often occurs resulting in viral resistance to current therapeutic regimens. Biodegradable poly(lactic-co-glycolic acid (PLGA) nanoparticles (NPs) are able to control the release of lamivudine and nevirapine, two current front-line therapeutic agents in Africa, and enhance cellular uptake in macrophages, a viral reservoir using a surface modifying sugar (chitosan). Common methods of NP fabrication predominantly result in NP sizes >200nm, however to utilize a hollow-fiber pharmacokinetic model to better optimize drug therapies, the size must be <200nm. Furthermore, a decreased size may also improve NP penetration to the brain, and decrease reticuloendothelial system (RES) capture. Methods: Core-shell chitosan-PLGA NPs were fabricated using a water-oil-water double emulsion (w/o/w) method, followed by solvent evaporation to encapsulate anti-retroviral drug(s). NPs were characterized for size and polydispersity using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA); surface charge using a zeta potential analyzer; surface morphology using transmission electron microscopy (TEM); and drug encapsulation, dissolution and intracellular concentration using high performance liquid chromatography (HPLC). Monocyte derived macrophages (MDMs) were cultured using standard approaches. Results: Core-shell NPs display a capsule-like morphology indicating a core-shell structure; a positive zeta potential when chitosan was incorporated during fabrication further confirming the core-shell structure; a decreased size (<150nm); and a sustained release over 24 hours. Intracellular drug concentrations in MDMs were higher in NP-drug formulations compared to free drug samples. Conclusions: In summary, we demonstrate that chitosan-PLGA NPs are capable of 1) being made to smaller dimensions using commonly available methods in the lab and 2) can encapsulate both lamivudine and nevirapine. These positively charged core-shell nanoparticles deliver therapeutics to viral reservoirs and are a revolutionary approach for a more effective, efficient and affordable treatment. 543 Chemical Facilitated Endosomal Storage of Long-Acting Antiretroviral Nanoparticles Dongwei Guo; Prasanta K. Dash ; Gang Zhang; Mariluz Arainga; Jaclyn Knibbe; JoEllyn McMillan; Larisa Poluektova; Harris Gelbard; Santhi Gorantla; Howard Gendelman University of Nebraska Medical Center, Omaha, NE, US Background: Suboptimal adherence to antiretroviral therapy (ART) for HIV-1 begets viral mutations and drug resistance. This might be reduced or eliminated by maintenance of plasma and tissue drug levels above an effective dose for prolonged time periods after single dose administration. To achieve this, we sought pharmacologic approaches that would augment ART depots in intracellular organelles free from pathways operative for drug elimination. Methods: A mixed lineage kinase-3 inhibitor URMC-099, developed in our laboratories, was investigated for its abilities to affect ART storage and antiviral activities. Humanized HIV-1 infected NOD/SCID/IL2R γ c − / − (NSG) mice and monocyte-derived macrophages (MDM) were treated with or without nanoformulated ritonavir (RTV)-boosted atazanavir (nanoATV/r), co-administered with URMC-099. 22-weeks old humanized-NSG mice were infected with HIV-1 ADA , followed by administration of URMC-099 daily and nanoformulated ATV and RTV (nanoART) weekly for three weeks starting 10 weeks post-infection, when the mice were at the peak of their viral load (VL). Peripheral VL, ratio of CD4 + and CD8 + T-lymphocytes, drug level in plasma and organs and pathological changes in lymphoid and brain tissues were investigated. Results: Co-administration of URMC-099 and nanoATV/r reduced viral load (VL) below detectable levels in plasma and reduced HIV-1p24+ lymphocyte numbers in spleen. We found very small amounts of residual HIV-1 found in infected humanized mice significantly below what was seen by nanoATV/r alone treatment. This effect on VL was associated with elevated nanoATV/r depots in macrophages and paralleled URMC-099 induction of ATV and RTV in spleen and liver. Proteomic and Western blot validation assays demonstrated that the antiretroviral effect was associated with accumulation of HIV-1 and nanoATV/r as well as reduced progeny virions in Rab 7- and 11-labeled recycling and late endosomes. URMC-099 induced dose-dependent reductions in HIV-1p24 and reverse transcriptase activity within Rab 5-, 7- and 11-labeled endosomes in infected human monocyte-derived macrophages but only when administered with nanoformulated drugs. Conclusions: Combination URMC-099 and nanoATV/r treatments offers a unique means to increase antiretroviral efficacy by enhancing accumulation of drug particle depots at endosomal sites of progeny virion maturation. 2:30 pm– 4:00 pm ART: Recent Perspectives 544 24-Weeks Virologic Efficacy of Fozivudine in ART-Naïve Patients From Africa Arne Kroidl 1 ;Tessa Lennemann 1 ; Frederic Ello 2 ; Jimson Mgaya 3 ; Raoul Moh 2 ; Lucas Maganga 3 ; Serge P. Eholié 2 ; Pierre-Marie Girard 4 ; Friedrich von Massow 5 ; Christine Danel 6 1 Medical Center of the University of Munich (LMU), Munich, Germany; 2 CHU de Treichville, Abidjan, Côte d’Ivoire; 3 NIMR–Mbeya Medical Research Center, Mbeya, United Republic of Tanzania; 4 University Hospital Saint-Antoine, Paris, France; 5 Institute for Life Sciences and Environment GmbH, Heidelberg, Germany; 6 Programme PAC-CI, ANRS, Abidjan, Côte d’Ivoire Background: Zidovudine (ZDV) is a frequently used NRTI in resources constraint settings but limited by toxicity. Fozivudine (FZD) is a ZDV pro-drug with a linked lipid domain and is bio-activated intracellularly to ZVD-monophosphate by outer membrane enzymes NPP1/3 preferentially expressed on mononuclear cells but not on bone marrow cells. FZD promises improved myelotoxicity profiles and once daily dosing. Methods: FATI-1 was a multicentre, randomized, open label phase II proof of concept and dose finding trial investigating three different FZD doses (800mg QD, 600mg BID, 1200mg QD) versus ZDV (300mg BID) plus 3TC and EFV in HIV infected, ART naïve patients from Tanzania and Côte d’Ivoire. The primary objective was to demonstrate virological efficacy after 24 weeks, secondary endpoints included toxicity and pharmacokinetic outcome. Endpoints were based on per protocol (PP) and intent-to treat (ITT) analysis, the latter including patients with treatment modifications due to toxicity or virologic failure only. Results: Treatment started in 119 participants (78% females, mean age 38 years, CD4 238 cells/ m l, HIV-RNA Log 10 4.99); characteristics did not differ between arms. Overall 105 (88.2%) participants were included in the PP and 110 (92.4%) in the ITT analysis. Reasons for early treatment modification were severe rash (1), elevated liver enzymes (1), severe anemia (2) and virologic failure (1). Week 24 outcome showed HIV-RNA <50 copies/ml in PP 83.8% (ITT 80.0%), <400 copies/ml in PP 91.4% (ITT 87.3%) with a mean PP CD4 increase of 127 cells/ m l. Outcome did not differ between study arms. Virologic failure >1000 copies/ml confirmed by two measurements was seen in 4 cases, no drug resistance TUESDAY, FEBRUARY 24, 2015 Session P-J1 Poster Session Poster Hall

Poster Abstracts

351

CROI 2015