Novel targets for anti-retroviral therapy

bTherapy for hepatitis C virus (HCV) infection has advanced with the recent approval of direct-acting antivirals in combination with peginterferon and ribavirin. New antivirals with novel targets are still needed to further improve the treatment of hepatitis C. Previously reported screening methods for HCV inhibitors either are limited to a virus-specific function or apply a screening method at a single dose, which usually leads to high false-positive or -negative rates. We developed a quantitative high-throughput screening (qHTS) assay platform with a cell-based HCV infection system. This highly sensitive assay can be miniaturized to a 1,536-well format for screening of large chemical libraries. All candidates are screened over a 7-concentration dose range to give EC 50 s (compound concentrations at 50% efficacy) and dose-response curves. Using this assay format, we screened a library of pharmacologically active compounds (LOPAC). Based on the profile of dose-dependent curves of HCV inhibition and cytotoxicity, 22 compounds with adequate curves and EC 50 s of <10 M were selected for validation. In two additional independent assays, 17 of them demonstrated specific inhibition of HCV infection. Ten potential candidates with efficacies of >70% and CC 50 s (compound concentrations at 50% cytotoxicity) of <30 M from these validated hits were characterized for their target stages in the HCV replication cycle. In this screen, we identified both known and novel hits with diverse structural and functional features targeting various stages of the HCV replication cycle. The pilot screen demonstrates that this assay system is highly robust and effective in identifying novel HCV inhibitors and that it can be readily applied to large-scale screening of small-molecule libraries.

Section: H Epatitis C Virus (Hcv) Infection Affects Approximately 200mentioning

confidence: 99%

Novel Cell-Based Hepatitis C Virus Infection Assay for Quantitative High-Throughput Screening of Anti-Hepatitis C Virus Compounds

Lan

et al. 2014

“…Plasma samples for analysis of ATV and RTV were obtained predose and at 1,2,3,4,6,8,12, and 24 h postdose on days 15 and 25. Physical examinations, measurement of vital signs, 12-lead electrocardiograms (ECGs), and clinical laboratory evaluations were performed at selected times throughout the study, and subjects were closely monitored for AEs and SAEs throughout the study.…”

Section: Methodsmentioning

confidence: 99%

“…here is an ongoing need for new classes of antiretroviral agents that can provide potent and durable activity against HIV-1, primarily due to the development of resistance to existing compounds and the need for improved safety and tolerability profiles compared with those of current treatments (1,2). Some HIV-positive patients, particularly treatment-experienced patients, may have limited treatment options owing to the presence of viral mutations causing reduced antiretroviral drug susceptibility, the emergence of drug toxicities from long-term antiretroviral therapy, and contraindications from the need to manage concurrent infections.…”

mentioning

confidence: 99%

Pharmacokinetic Interactions between BMS-626529, the Active Moiety of the HIV-1 Attachment Inhibitor Prodrug BMS-663068, and Ritonavir or Ritonavir-Boosted Atazanavir in Healthy Subjects

Zhu

Hruska

Hwang

et al. 2015

BMS-663068 is a prodrug of BMS-626529, a first-in-class attachment inhibitor that binds directly to HIV-1 gp120, preventing initial viral attachment and entry into host CD4 ؉ T cells. This open-label, multiple-dose, four-sequence, crossover study addressed potential two-way drug-drug interactions following coadministration of BMS-663068 (BMS-626529 is a CYP3A4 substrate), atazanavir (ATV), and ritonavir (RTV) (ATV and RTV are CYP3A4 inhibitors). Thirty-six healthy subjects were randomized 1:1:1:1 to receive one of four treatment sequences with three consecutive treatments: BMS-663068 at 600 mg twice daily (BID), BMS-663068 at 600 mg BID plus RTV at 100 mg once daily (QD), ATV at 300 mg QD plus RTV at 100 mg QD (

“…ue to their high rates of mutation, drug-resistant human immunodeficiency virus type 1 (HIV-1) strains arise constantly, necessitating the development of drugs with new distinct structures or possessing different mechanisms of action that can be used in the treatment of HIV-1 infections and patients presenting with AIDS (1). Oligonucleotides represent a category of anti-HIV-1 drug candidates, including small interfering RNA (siRNA) and antisense oligonucleotides that specifically interact with target genes via complementary base pairing (2)(3)(4)(5).…”

mentioning

confidence: 99%

DNA Duplexes with Hydrophobic Modifications Inhibit Fusion between HIV-1 and Cell Membranes

Xu¹,

Cai²,

Chen

et al. 2013

Discovery of new drugs for the treatment of AIDS typically possessing unique structures associated with novel mechanisms of action has been of great importance due to the quick drug-resistant mutations of HIV-1 strains. The work presented in this report describes a novel class of DNA duplex-based HIV-1 fusion inhibitors. Hydrophobic groups were introduced into a DNA duplex skeleton either at one end, at both ends, or in the middle. These modified DNA duplexes inhibited fusion between HIV-1 and human cell membranes at micro-or submicromolar concentrations. Respective inhibitors adopted an aptamer pattern instead of a base-pairing interaction pattern. Structure-activity relationship studies of the respective DNA duplexes showed that the rigid and negatively charged DNA skeletons, in addition to the presence of hydrophobic groups, were crucial to the anti-HIV-1 activity of these compounds. A fluorescent resonance energy transfer (FRET)-based inhibitory assay showed that these duplex inhibitors interacted with the primary pocket in the gp41 N-terminal heptad repeat (NHR) instead of interacting with the lipid bilayers.