scholarly journals Comparison of Drug Resistance Scores for Tipranavir in Protease Inhibitor-Naïve Patients Infected with HIV-1 B and Non-B Subtypes

2011 ◽  
Vol 55 (11) ◽  
pp. 5362-5366 ◽  
Author(s):  
Martin Stürmer ◽  
Christoph Stephan ◽  
Peter Gute ◽  
Gaby Knecht ◽  
Markus Bickel ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Protease Inhibitor ◽  
Natural Resistance ◽  
Content Type ◽  
Prediction Algorithms ◽  
Resistance Prediction ◽  
Hiv 1

ABSTRACTGenotypes of samples from protease inhibitor-naïve patients in Frankfurt's HIV Cohort were analyzed with five tipranavir resistance prediction algorithms. Mean scores were higher in non-B than in B subtypes. The proportion of non-B subtypes increased with increasing scores, except in weighted algorithms. Virtual andin vitrophenotype analyses of samples with increased scores showed no reduced tipranavir susceptibility. Current algorithms appear suboptimal for interpretation of resistance to tipranavir in non-B subtypes; increased scores might reflect algorithm bias rather than “natural resistance.”

scholarly journals Efficient Identification of Human Immunodeficiency Virus Type 1 Mutants Resistant to a Protease Inhibitor by Using a Random Mutant Library

2011 ◽  
Vol 55 (11) ◽  
pp. 5090-5098 ◽  
Author(s):  
Sanggu Kim ◽  
Yun-Cheol Kim ◽  
Hangfei Qi ◽  
Kunkai Su ◽  
Sherie L. Morrison ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Drug Resistance ◽  
Protease Inhibitor ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Drug Resistant ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACTEmergence of drug-resistant mutant viruses during the course of antiretroviral therapy is a major hurdle that limits the success of chemotherapeutic treatment to suppress human immunodeficiency virus type 1 (HIV-1) replication and AIDS progression. Development of new drugs and careful patient management based on resistance genotyping data are important for enhancing therapeutic efficacy. However, identifying changes leading to drug resistance can take years of clinical studies, and conventionalin vitroassays are limited in generating reliable drug resistance data. Here we present an efficientin vitroscreening assay for selecting drug-resistant variants from a library of randomly mutated HIV-1 strains generated by transposon-directed base-exchange mutagenesis. As a test of principle, we screened a library of mutant HIV-1 strains containing random mutations in the protease gene by using a reporter T-cell line in the presence of the protease inhibitor (PI) nelfinavir (NFV). Analysis of replicating viruses from a single round of infection identified 50 amino acid substitutions at 35 HIV-1 protease residue positions. The selected mutant viruses showed specific resistance to NFV and included most of the known NFV resistance mutations. Therefore, the new assay is efficient for identifying changes leading to drug resistance. The data also provide insights into the molecular mechanisms underlying the development of drug resistance.

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.

In vitro susceptibility of clinical isolates of HIV-1 to XM323, a non-peptidyl HIV protease inhibitor

AIDS ◽  
1994 ◽  
Vol 8 (6) ◽  
pp. 753-756 ◽  
Author(s):  
Dean L. Winslow ◽  
Douglas Mayers ◽  
Helen Scarnati ◽  
James Lane ◽  
Arlene Bincsik ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Clinical Isolates ◽  
Hiv Protease ◽  
Hiv Protease Inhibitor ◽  
In Vitro Susceptibility ◽  
Hiv 1

scholarly journals Drug Susceptibility Profiling and Genetic Determinants of Drug Resistance inMycobacterium kansasii

2018 ◽  
Vol 62 (4) ◽  
pp. e01788-17 ◽  
Author(s):  
Zofia Bakuła ◽  
Magdalena Modrzejewska ◽  
Lian Pennings ◽  
Małgorzata Proboszcz ◽  
Aleksandra Safianowska ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Target Genes ◽  
Regulatory Region ◽  
Drug Susceptibility ◽  
Dilution Method ◽  
Broth Microdilution ◽  
Genetic Determinants ◽  
Content Type ◽  
Microdilution Method

ABSTRACTVery few studies have examined drug susceptibility ofMycobacterium kansasii, and they involve a limited number of strains. The purpose of this study was to determine drug susceptibility profiles ofM. kansasiiisolates representing a spectrum of species genotypes (subtypes) with two different methodologies, i.e., broth microdilution and Etest assays. To confirm drug resistance, drug target genes were sequenced. A collection of 85M. kansasiiisolates, including representatives of eight different subtypes (I to VI, I/II, and IIB) from eight countries, was used. Drug susceptibility against 13 and 8 antimycobacterial agents was tested by using broth microdilution and Etest, respectively. For drug-resistant or high-MIC isolates, eight structural genes (rrl,katG,inhA,embB,rrs,rpsL,gyrA, andgyrB) and one regulatory region (embCA) were PCR amplified and sequenced in the search for resistance-associated mutations. All isolates tested were susceptible to rifampin (RIF), amikacin (AMK), co-trimoxazole (SXT), rifabutin (RFB), moxifloxacin (MXF), and linezolid (LZD) according to the microdilution method. Resistance to ethambutol (EMB), ciprofloxacin (CIP), and clarithromycin (CLR) was found in 83 (97.7%), 17 (20%), and 1 (1.2%) isolate, respectively. The calculated concordance between the Etest and dilution method was 22.6% for AMK, 4.8% for streptomycin (STR), 3.2% for CLR, and 1.6% for RIF. For EMB, INH, and SXT, not even a single MIC value determined by one method equaled that by the second method. The only mutations disclosed were A2266C transversion at therrlgene (CLR-resistant strain) and A128G transition at therpsLgene (strain with STR MIC of >64 mg/liter). In conclusion, eight drugs, including RIF, CLR, AMK, SXT, RFB, MXF, LZD, and ethionamide (ETO), showed highin vitroactivity againstM. kansasiiisolates. Discrepancies of the results between the reference microdilution method and Etest preclude the use of the latter for drug susceptibility determination inM. kansasii. Drug resistance inM. kansasiimay have different genetic determinants than resistance to the same drugs inM. tuberculosis.

A C2 Symmetry-Based HIV Protease Inhibitor, A77003, Irreversibly Inhibits Infectivity of HIV-1 In Vitro

1994 ◽  
Vol 10 (6) ◽  
pp. 735-743 ◽  
Author(s):  
SEIJI KAGEYAMA ◽  
DAVID T. HOEKZEMA ◽  
YOHKO MURAKAWA ◽  
EIJI KOJIMA ◽  
TAKUMA SHIRASAKA ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Hiv Protease ◽  
Hiv Protease Inhibitor ◽  
Hiv 1

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 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 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.

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