scholarly journals Circulating Metabolites of the Human Immunodeficiency Virus Protease Inhibitor Nelfinavir in Humans: Structural Identification, Levels in Plasma, and Antiviral Activities

2001 ◽  
Vol 45 (4) ◽  
pp. 1086-1093 ◽  
Author(s):  
Kanyin E. Zhang ◽  
Ellen Wu ◽  
Amy K. Patick ◽  
Bradley Kerr ◽  
Mark Zorbas ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Protease Inhibitor ◽  
Active Metabolite ◽  
Parent Drug ◽  
Hiv Reverse Transcriptase ◽  
Immunodeficiency Virus ◽  
Antiviral Activities ◽  
Hiv 1

ABSTRACT Nelfinavir mesylate (Viracept, formally AG1343) is a potent and orally bioavailable human immunodeficiency virus (HIV) type 1 (HIV-1) protease inhibitor (K i = 2 nM) and is being widely prescribed in combination with HIV reverse transcriptase inhibitors for the treatment of HIV infection. The current studies evaluated the presence of metabolites circulating in plasma following the oral administration of nelfinavir to healthy volunteers and HIV-infected patients, as well as the levels in plasma and antiviral activities of these metabolites. The results showed that the parent drug was the major circulating chemical species, followed in decreasing abundance by its hydroxy-t-butylamide metabolite (M8) and 3′-methoxy-4′-hydroxynelfinavir (M1). Antiviral assays with HIV-1 strain RF-infected CEM-SS cells showed that the 50% effective concentrations (EC50) of nelfinavir, M8, and M1 were 30, 34, and 151 nM, respectively, and that the corresponding EC50 against another HIV-1 strain, IIIB, in MT-2 cells were 60, 86, and 653 nM. Therefore, apparently similar in vitro antiviral activities were demonstrated for nelfinavir and M8, whereas an approximately 5- to 11-fold-lower level of antiviral activity was observed for M1. The active metabolite, M8, showed a degree of binding to human plasma proteins similar to that of nelfinavir (ca. 98%). Concentrations in plasma of nelfinavir and its metabolites in 10 HIV-positive patients receiving nelfinavir therapy (750 mg three times per day) were determined by a liquid chromatography tandem mass spectrometry assay. At steady state (day 28), the mean plasma nelfinavir concentrations ranged from 1.73 to 4.96 μM and the M8 concentrations ranged from 0.55 to 1.96 μM, whereas the M1 concentrations were low and ranged from 0.09 to 0.19 μM. In conclusion, the findings from the current studies suggest that, in humans, nelfinavir forms an active metabolite circulating at appreciable levels in plasma. The active metabolite M8 may account for some of the antiviral activity associated with nelfinavir in the treatment of HIV disease.

scholarly journals In Vitro Antiviral Activity of the Novel, Tyrosyl-Based Human Immunodeficiency Virus (HIV) Type 1 Protease Inhibitor Brecanavir (GW640385) in Combination with Other Antiretrovirals and against a Panel of Protease Inhibitor-Resistant HIV

2007 ◽  
Vol 51 (9) ◽  
pp. 3147-3154 ◽  
Author(s):  
Richard Hazen ◽  
Robert Harvey ◽  
Robert Ferris ◽  
Charles Craig ◽  
Phillip Yates ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Protease Inhibitor ◽  
Reverse Transcriptase ◽  
In Vitro Assays ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT Brecanavir, a novel tyrosyl-based arylsulfonamide, high-affinity, human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI), has been evaluated for anti-HIV activity in several in vitro assays. Preclinical assessment of brecanavir indicated that this compound potently inhibited HIV-1 in cell culture assays with 50% effective concentrations (EC50s) of 0.2 to 0.53 nM and was equally active against HIV strains utilizing either the CXCR4 or CCR5 coreceptor, as was found with other PIs. The presence of up to 40% human serum decreased the anti-HIV-1 activity of brecanavir by 5.2-fold, but under these conditions the compound retained single-digit nanomolar EC50s. When brecanavir was tested in combination with nucleoside reverse transcriptase inhibitors, the antiviral activity of brecanavir was synergistic with the effects of stavudine and additive to the effects of zidovudine, tenofovir, dideoxycytidine, didanosine, adefovir, abacavir, lamivudine, and emtricitabine. Brecanavir was synergistic with the nonnucleoside reverse transcriptase inhibitor nevirapine or delavirdine and was additive to the effects of efavirenz. In combination with other PIs, brecanavir was additive to the activities of indinavir, lopinavir, nelfinavir, ritonavir, amprenavir, saquinavir, and atazanavir. Clinical HIV isolates from PI-experienced patients were evaluated for sensitivity to brecanavir and other PIs in a recombinant virus assay. Brecanavir had a <5-fold increase in EC50s against 80% of patient isolates tested and had a greater mean in vitro potency than amprenavir, indinavir, lopinavir, atazanavir, tipranavir, and darunavir. Brecanavir is by a substantial margin the most potent and broadly active antiviral agent among the PIs tested in vitro.

scholarly journals In Vitro Antiviral Activity and Cross-Resistance Profile of PL-100, a Novel Protease Inhibitor of Human Immunodeficiency Virus Type 1

2007 ◽  
Vol 51 (11) ◽  
pp. 4036-4043 ◽  
Author(s):  
Serge Dandache ◽  
Guy Sévigny ◽  
Jocelyn Yelle ◽  
Brent R. Stranix ◽  
Neil Parkin ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Highly Active Antiretroviral Therapy ◽  
Cross Resistance ◽  
Drug Resistant ◽  
Resistance Profile ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Despite the success of highly active antiretroviral therapy, the current emergence and spread of drug-resistant variants of human immunodeficiency virus (HIV) stress the need for new inhibitors with distinct properties. We designed, produced, and screened a library of compounds based on an original l-lysine scaffold for their potentials as HIV type 1 (HIV-1) protease inhibitors (PI). One candidate compound, PL-100, emerged as a specific and noncytotoxic PI that exhibited potent inhibition of HIV-1 protease and viral replication in vitro (Ki , ∼36 pM, and 50% effective concentration [EC50], ∼16 nM, respectively). To confirm that PL-100 possessed a favorable resistance profile, we performed a cross-resistance study using a panel of 63 viral strains from PI-experienced patients selected for the presence of primary PI mutations known to confer resistance to multiple PIs now in clinical use. The results showed that PL-100 retained excellent antiviral activity against almost all of these PI-resistant viruses and that its performance in this regard was superior to those of atazanavir, amprenavir, indinavir, lopinavir, nelfinavir, and saquinavir. In almost every case, the increase in the EC50 for PL-100 observed with viruses containing multiple mutations in protease was far less than that obtained with the other drugs tested. These data underscore the potential for PL-100 to be used in the treatment of drug-resistant HIV disease and argue for its further development.

scholarly journals Novel bis-Tetrahydrofuranylurethane-Containing Nonpeptidic Protease Inhibitor (PI) UIC-94017 (TMC114) with Potent Activity against Multi-PI-Resistant Human Immunodeficiency Virus In Vitro

2003 ◽  
Vol 47 (10) ◽  
pp. 3123-3129 ◽  
Author(s):  
Yasuhiro Koh ◽  
Hirotomo Nakata ◽  
Kenji Maeda ◽  
Hiromi Ogata ◽  
Geoffrey Bilcer ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Therapeutic Agent ◽  
Close Contact ◽  
Wide Spectrum ◽  
Antiviral Agents ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We designed, synthesized, and identified UIC-94017 (TMC114), a novel nonpeptidic human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) containing a 3(R),3a(S),6a(R)-bis-tetrahydrofuranylurethane (bis-THF) and a sulfonamide isostere which is extremely potent against laboratory HIV-1 strains and primary clinical isolates (50% inhibitory concentration [IC50], ∼0.003 μM; IC90, ∼0.009 μM) with minimal cytotoxicity (50% cytotoxic concentration for CD4+ MT-2 cells, 74 μM). UIC-94017 blocked the infectivity and replication of each of HIV-1NL4-3 variants exposed to and selected for resistance to saquinavir, indinavir, nelfinavir, or ritonavir at concentrations up to 5 μM (IC50s, 0.003 to 0.029 μM), although it was less active against HIV-1NL4-3 variants selected for resistance to amprenavir (IC50, 0.22 μM). UIC-94017 was also potent against multi-PI-resistant clinical HIV-1 variants isolated from patients who had no response to existing antiviral regimens after having received a variety of antiviral agents. Structural analyses revealed that the close contact of UIC-94017 with the main chains of the protease active-site amino acids (Asp-29 and Asp-30) is important for its potency and wide spectrum of activity against multi-PI-resistant HIV-1 variants. Considering the favorable pharmacokinetics of UIC-94017 when administered with ritonavir, the present data warrant that UIC-94017 be further developed as a potential therapeutic agent for the treatment of primary and multi-PI-resistant HIV-1 infections.

scholarly journals TMC310911, a Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, ShowsIn Vitroan Improved Resistance Profile and Higher Genetic Barrier to Resistance Compared with Current Protease Inhibitors

2011 ◽  
Vol 55 (12) ◽  
pp. 5723-5731 ◽  
Author(s):  
Inge Dierynck ◽  
Herwig Van Marck ◽  
Marcia Van Ginderen ◽  
Tim H. M. Jonckers ◽  
Madhavi N. L. Nalam ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Clinical Isolates ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Selection Of

ABSTRACTTMC310911 is a novel human immunodeficiency virus type 1 (HIV-1) protease inhibitor (PI) structurally closely related to darunavir (DRV) but with improved virological characteristics. TMC310911 has potent activity against wild-type (WT) HIV-1 (median 50% effective concentration [EC50], 14 nM) and a wide spectrum of recombinant HIV-1 clinical isolates, including multiple-PI-resistant strains with decreased susceptibility to currently approved PIs (fold change [FC] in EC50, >10). For a panel of 2,011 recombinant clinical isolates with decreased susceptibility to at least one of the currently approved PIs, the FC in TMC310911 EC50was ≤4 for 82% of isolates and ≤10 for 96% of isolates. The FC in TMC310911 EC50was ≤4 and ≤10 for 72% and 94% of isolates with decreased susceptibility to DRV, respectively.In vitroresistance selection (IVRS) experiments with WT virus and TMC310911 selected for mutations R41G or R41E, but selection of resistant virus required a longer time than IVRS performed with WT virus and DRV. IVRS performed with r13025, a multiple-PI-resistant recombinant clinical isolate, and TMC310911 selected for mutations L10F, I47V, and L90M (FC in TMC310911 EC50= 16). IVRS performed with r13025 in the presence of DRV required less time and resulted in more PI resistance-associated mutations (V32I, I50V, G73S, L76V, and V82I; FC in DRV EC50= 258). The activity against a comprehensive panel of PI-resistant mutants and the limitedin vitroselection of resistant viruses under drug pressure suggest that TMC310911 represents a potential drug candidate for the management of HIV-1 infection for a broad range of patients, including those with multiple PI resistance.

scholarly journals Safety and Pharmacokinetics of Brecanavir, a Novel Human Immunodeficiency Virus Type 1 Protease Inhibitor, following Repeat Administration with and without Ritonavir in Healthy Adult Subjects

2007 ◽  
Vol 51 (4) ◽  
pp. 1202-1208 ◽  
Author(s):  
Y. Sunila Reddy ◽  
Susan L. Ford ◽  
Maggie T. Anderson ◽  
Sharon C. Murray ◽  
Judith Ng-Cashin ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Geometric Mean ◽  
Repeat Dose ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Immunodeficiency Virus ◽  
Potent Protease Inhibitor ◽  
Hiv 1

ABSTRACT Brecanavir (BCV) is a novel, potent protease inhibitor in development for the treatment of human immunodeficiency virus (HIV-1) infection with low nM in vitro 50% inhibitory concentrations (IC50s) against many multiprotease inhibitor resistant viruses. This study was a double-blind, randomized, placebo-controlled repeat-dose escalation to evaluate the safety, tolerability, and pharmacokinetics of BCV, with or without ritonavir (RTV), in 68 healthy subjects. Seven sequential cohorts (n = 10) received BCV (50 to 600 mg) in combination with 100 mg RTV (every 12 h [q12h] or q24h) or alone at 800 mg q12h for 15 days. BCV alone or in combination with RTV was well tolerated, with no serious adverse events reported. The most common drug-related adverse event was headache. BCV was readily absorbed with median time to maximum concentration of drug in serum values ranging from 2.5 to 5.0 h postdose following single- and repeat-dose administration of BCV alone and BCV with RTV 100 mg. Geometric mean BCV accumulation ratios ranged from 1.4 to 1.56 following BCV-RTV q24h regimens and from 1.84 to 4.93 following BCV q12h regimens. BCV steady state was generally achieved by day 13 in all groups. All day 15 BCV-RTV trough concentration values in q12h regimens reached or surpassed the estimated protein-binding corrected in vitro IC50 target BCV concentration of 28 ng/ml for highly resistant isolates. The pharmacokinetic and safety profile of BCV-RTV supports continued investigation in HIV-1-infected subjects.

scholarly journals Structural and Kinetic Analyses of the Protease from an Amprenavir-Resistant Human Immunodeficiency Virus Type 1 Mutant Rendered Resistant to Saquinavir and Resensitized to Amprenavir

2000 ◽  
Vol 74 (16) ◽  
pp. 7636-7641 ◽  
Author(s):  
W. Markland ◽  
B. G. Rao ◽  
J. D. Parsons ◽  
J. Black ◽  
L. Zuchowski ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Structural Basis ◽  
Term Therapy ◽  
Triple Mutant ◽  
New Variant ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Recent drug regimens have had much success in the treatment of human immunodeficiency virus (HIV)-infected individuals; however, the incidence of resistance to such drugs has become a problem that is likely to increase in importance with long-term therapy of this chronic illness. An analysis and understanding of the molecular interactions between the drug(s) and the mutated viral target(s) is crucial for further progress in the field of AIDS therapy. The protease inhibitor amprenavir (APV) generates a signature set of HIV type 1 (HIV-1) protease mutations associated with in vitro resistance (M46I/L, I47V, and I50V [triple mutant]). Passage of the triple-mutant APV-resistant HIV-1 strain in MT4 cells, in the presence of increasing concentrations of saquinavir (SQV), gave rise to a new variant containing M46I, G48V, I50V, and I84L mutations in the protease and a resulting phenotype that was resistant to SQV and, unexpectedly, resensitized to APV. This phenotype was consistent with a subsequent kinetic analysis of the mutant protease, together with X-ray crystallographic analysis and computational modeling which elucidated the structural basis of these observations. The switch in protease inhibitor sensitivities resulted from (i) the I50V mutation, which reduced the area of contact with APV and SQV; (ii) the compensating I84L mutation, which improved hydrophobic packing with APV; and (iii) the G-to-V mutation at residue 48, which introduced steric repulsion with the P3 group of SQV. This analysis establishes the fine detail necessary for understanding the loss of protease binding for SQV in the quadruple mutant and gain in binding for APV, demonstrating the powerful combination of virology, molecular biology, enzymology, and protein structural and modeling studies in the elucidation and understanding of viral drug resistance.

scholarly journals Estimate of the Frequency of Human Immunodeficiency Virus Type 1 Protease Inhibitor Resistance within Unselected Virus Populations In Vitro

1998 ◽  
Vol 42 (2) ◽  
pp. 478-480 ◽  
Author(s):  
Simon P. Tucker ◽  
Thomas R. Stiebel ◽  
Karen E. Potts ◽  
Mary L. Smidt ◽  
Martin L. Bryant
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Resistant Variant ◽  
Immunodeficiency Virus ◽  
Inhibitor Resistance ◽  
Hiv 1

ABSTRACT The frequency of drug-resistant human immunodeficiency virus type 1 (HIV-1) variants in virus populations not previously exposed to drug was determined in vitro by using HIV-1RF and the protease inhibitor SC-55389A. Two variants with single mutations responsible for drug resistance (V82A and N88S) were quantifiably isolated after only one round of replication, yielding a crude frequency estimate of at least 1 SC-55389A-resistant variant per 3.5 × 105wild-type infectious units.

scholarly journals Selective Intracellular Activation of a Novel Prodrug of the Human Immunodeficiency Virus Reverse Transcriptase Inhibitor Tenofovir Leads to Preferential Distribution and Accumulation in Lymphatic Tissue

2005 ◽  
Vol 49 (5) ◽  
pp. 1898-1906 ◽  
Author(s):  
William A. Lee ◽  
Gong-Xin He ◽  
Eugene Eisenberg ◽  
Tomas Cihlar ◽  
Swami Swaminathan ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Half Life ◽  
Mononuclear Cells ◽  
Parent Drug ◽  
Transcriptase Inhibitor ◽  
Peripheral Blood Mononuclear ◽  
Cell Extracts ◽  
Immunodeficiency Virus

ABSTRACT An isopropylalaninyl monoamidate phenyl monoester prodrug of tenofovir (GS 7340) was prepared, and its in vitro antiviral activity, metabolism, and pharmacokinetics in dogs were determined. The 50% effective concentration (EC50) of GS 7340 against human immunodeficiency virus type 1 in MT-2 cells was 0.005 μM compared to an EC50 of 5 μM for the parent drug, tenofovir. The (L)-alaninyl analog (GS 7340) was >1,000-fold more active than the (D)-alaninyl analog. GS 7340 has a half-life of 90 min in human plasma at 37°C and a half-life of 28.3 min in an MT-2 cell extract at 37°C. The antiviral activity (>10× the EC50) and the metabolic stability in MT-2 cell extracts (>35×) and plasma (>2.5×) were also sensitive to the stereochemistry at the phosphorus. After a single oral dose of GS 7340 (10 mg-eq/kg tenofovir) to male beagle dogs, the plasma bioavailability of tenofovir compared to an intravenous dose of tenofovir was 17%. The total intracellular concentration of all tenofovir species in isolated peripheral blood mononuclear cells at 24 h was 63 μg-eq/ml compared to 0.2 μg-eq/ml in plasma. A radiolabeled distribution study with dogs resulted in an increased distribution of tenofovir to tissues of lymphatic origin compared to the commercially available prodrug tenofovir DF (Viread).

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