Combination Therapy with Zidovudine Prevents Selection of Human Immunodeficiency Virus Type 1 Variants Expressing High-Level Resistance to L-697,661, a Nonnucleoside Reverse Transcriptase Inhibitor

1995 ◽  
Vol 171 (5) ◽  
pp. 1159-1165 ◽  
Author(s):  
S. Staszewski ◽  
F. E. Massari ◽  
A. Kober ◽  
R. Gohler ◽  
S. Durr ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Combination Therapy ◽  
Transcriptase Inhibitor ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
High Level ◽  
Reverse Transcriptase Inhibitor ◽  
Level Resistance ◽  
Selection Of

scholarly journals In Vitro Microbicidal Activity of the Nonnucleoside Reverse Transcriptase Inhibitor (NNRTI) UC781 against NNRTI-Resistant Human Immunodeficiency Virus Type 1

2006 ◽  
Vol 80 (9) ◽  
pp. 4440-4446 ◽  
Author(s):  
Mohammad M. Hossain ◽  
Michael A. Parniak
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Resistant Virus ◽  
Microbicidal Activity ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT The nonnucleoside reverse transcriptase inhibitor (NNRTI) UC781 is under development as a microbicide to prevent sexual transmission of the human immunodeficiency virus type 1 (HIV-1). However, NNRTI-resistant HIV-1 is increasingly prevalent in the infected population, and one of the concerns for NNRTI-based microbicides is that they will be ineffective against drug-resistant virus and may in fact selectively transmit NNRTI-resistant virus. We evaluated the microbicidal activity of UC781 against UC781-resistant (UCR), efavirenz-resistant (EFVR), and nevirapine-resistant (NVPR) strains in a variety of microbicide-relevant tests, including inactivation of cell-free virus, inhibition of cell-to-cell HIV-1 transmission, and the ability of UC781 pretreatment to protect cells from subsequent infection in the absence of exogenous drug. UC781 was 10- to 100-fold less effective against NNRTI-resistant HIV-1 compared to wild-type (wt) virus in each of these tests, with UC781 microbicidal activity against the various virus strains being wt ≥ NVPR > UCR ≥ EFVR. Breakthrough experiments using UC781-pretreated cells and mixtures of wt and NNRTI-resistant HIV-1 showed that UC781-pretreatment selected for NNRTI-resistant HIV-1. However, the efficacy of UC781 was dose dependent, and 25 μM UC781 provided essentially equivalent microbicidal activity against NNRTI-resistant and wt virus. The amount of UC781 in topical microbicide formulations under current development is approximately 100-fold greater than this concentration, so transmission of NNRTI-resistant virus may not be an issue at these microbicide formulation levels of UC781. Nonetheless, the reduced microbicidal activity of UC781 against NNRTI-resistant HIV-1 suggests that additional antiviral agents should be included in NNRTI-based microbicide formulations.

scholarly journals Single-Dose Escalation and Multiple-Dose Safety, Tolerability, and Pharmacokinetics of IDX899, a Candidate Human Immunodeficiency Virus Type 1 Nonnucleoside Reverse Transcriptase Inhibitor, in Healthy Subjects

2009 ◽  
Vol 53 (5) ◽  
pp. 1739-1746 ◽  
Author(s):  
Xiao-Jian Zhou ◽  
Keith Pietropaolo ◽  
David Damphousse ◽  
Bruce Belanger ◽  
Jie Chen ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Single Dose ◽  
Adverse Events ◽  
Transcriptase Inhibitor ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT IDX899 is a novel nonnucleoside reverse transcriptase inhibitor (NNRTI) with potent in vitro activity against wild-type and NNRTI-resistant strains of human immunodeficiency virus type 1 (HIV-1) and with a high genetic barrier to resistance. Single rising doses of 50 and 100 (given by use of a 50-mg capsule) and 200, 400, 800, and 1,200 mg (given by use of a 200-mg capsule) of IDX899 or matching placebo were administered sequentially to cohorts of healthy male subjects, followed by the administration of multiple doses of 800 mg once daily (QD) or 400 mg twice daily (BID) for 7 days. A single dose of 400 mg was also administered to a cohort of females. IDX899 was administered orally under fasted (50- to 400-mg doses) and then fed (≥200-mg doses) conditions. Exposure to IDX899 was dose proportional and comparable in males and females. With a different drug-to-excipient ratio, the 50-mg capsule led to a higher exposure but a shorter mean terminal half-life (t 1/2) of 6.2 to 6.8 h. The 200-mg capsule resulted in a more sustained exposure with a longer mean t 1/2 of 7.9 to 14.6 h. Food enhanced absorption by approximately twofold, while it delayed the time to the maximum concentration. The mean concentration at 24 h following the administration of a single 200-mg dose under fed conditions exceeded the in vitro protein binding-adjusted 90% inhibitory concentration by fourfold. The levels of plasma exposure were similar between the single dosing and the repeat dosing with 800 mg QD and was approximately twofold higher with 400 mg BID. Mean steady-state trough levels were 0.9 μg/ml (range, 0.2 to 2.5 μg/ml) and 2.1 μg/ml (range, 0.5 to 4.5 μg/ml) for the 800-mg QD and 400-mg BID regimens, respectively. The level of excretion of unchanged drug in urine was negligible. IDX899 was well tolerated; and no serious adverse events, dose-dependent adverse events, or laboratory abnormalities were detected. These favorable safety and pharmacokinetic results support further clinical studies with patients with HIV-1 infection by the use of a QD regimen.

scholarly journals Inhibition of Human Immunodeficiency Virus Type 1 Infection by the Candidate Microbicide Dapivirine, a Nonnucleoside Reverse Transcriptase Inhibitor

2008 ◽  
Vol 53 (2) ◽  
pp. 487-495 ◽  
Author(s):  
P. Fletcher ◽  
S. Harman ◽  
H. Azijn ◽  
N. Armanasco ◽  
P. Manlow ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Transcriptase Inhibitor ◽  
Heterosexual Transmission ◽  
Inhibitory Effects ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Wide Range ◽  
Immunodeficiency Virus ◽  
Reverse Transcriptase Inhibitor

ABSTRACT Heterosexual transmission of human immunodeficiency virus (HIV) remains the major route of infection worldwide; thus, there is an urgent need for additional prevention strategies, particularly strategies that could be controlled by women, such as topical microbicides. Potential microbicide candidates must be both safe and effective. Using cellular and tissue explant models, we have evaluated the activity of the nonnucleoside reverse transcriptase inhibitor (NNRTI) dapivirine as a vaginal microbicide. In tissue compatibility studies, dapivirine was well tolerated by epithelial cells, T cells, macrophages, and cervical tissue explants. Dapivirine demonstrated potent dose-dependent inhibitory effects against a broad panel of HIV type 1 isolates from different clades. Furthermore, dapivirine demonstrated potent activity against a wide range of NNRTI-resistant isolates. In human cervical explant cultures, dapivirine was able not only to inhibit direct infection of mucosal tissue but also to prevent the dissemination of the virus by migratory cells. Activity was retained in the presence of semen or a cervical mucus simulant. Furthermore, dapivirine demonstrated prolonged inhibitory effects: it was able to prevent both localized and disseminated infection for as long as 6 days posttreatment. The prolonged protection observed following pretreatment of genital tissue and the lack of observable toxicity suggest that dapivirine has considerable promise as a potential microbicide candidate.

scholarly journals Safety Assessment, In Vitro and In Vivo, and Pharmacokinetics of Emivirine, a Potent and Selective Nonnucleoside Reverse Transcriptase Inhibitor of Human Immunodeficiency Virus Type 1

2000 ◽  
Vol 44 (1) ◽  
pp. 123-130 ◽  
Author(s):  
G. M. Szczech ◽  
P. Furman ◽  
G. R. Painter ◽  
D. W. Barry ◽  
K. Borroto-Esoda ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Dose ◽  
Transcriptase Inhibitor ◽  
Nonnucleoside Reverse Transcriptase Inhibitor ◽  
Immunodeficiency Virus ◽  
Reverse Transcriptase Inhibitor ◽  
Hiv 1

ABSTRACT Emivirine (EMV), formerly known as MKC-442, is 6-benzyl-1-(ethoxymethyl)-5-isopropyl-uracil, a novel nonnucleoside reverse transcriptase inhibitor that displays potent and selective anti-human immunodeficiency virus type 1 (HIV-1) activity in vivo. EMV showed little or no toxicity towards human mitochondria or human bone marrow progenitor cells. Pharmacokinetics were linear for both rats and monkeys, and oral absorption was 68% in rats. Whole-body autoradiography showed widespread distribution in tissue 30 min after rats were given an oral dose of [14C]EMV at 10 mg/kg of body weight. In rats given an oral dose of 250 mg/kg, there were equal levels of EMV in the plasma and the brain. In vitro experiments using liver microsomes demonstrated that the metabolism of EMV by human microsomes is approximately a third of that encountered with rat and monkey microsomes. In 1-month, 3-month, and chronic toxicology experiments (6 months with rats and 1 year with cynomolgus monkeys), toxicity was limited to readily reversible effects on the kidney consisting of vacuolation of kidney tubular epithelial cells and mild increases in blood urea nitrogen. Liver weights increased at the higher doses in rats and monkeys and were attributed to the induction of drug-metabolizing enzymes. EMV tested negative for genotoxic activity, and except for decreased feed consumption at the high dose (160 mg/kg/day), with resultant decreases in maternal and fetal body weights, EMV produced no adverse effects in a complete range of reproductive toxicology experiments performed on rats and rabbits. These results support the clinical development of EMV as a treatment for HIV-1 infection in adult and pediatric patient populations.

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