scholarly journals Anti-Human Immunodeficiency Virus Interactions of SCH-C (SCH 351125), a CCR5 Antagonist, with Other Antiretroviral Agents In Vitro

2002 ◽  
Vol 46 (5) ◽  
pp. 1336-1339 ◽  
Author(s):  
Cécile L. Tremblay ◽  
Françoise Giguel ◽  
Christopher Kollmann ◽  
Yongbiao Guan ◽  
Ting-Chao Chou ◽  
...  

ABSTRACT SCH-C (SCH 351125) is a small-molecule antagonist of the human immunodeficiency virus type 1(HIV-1) coreceptor CCR5. It has in vitro activity against R5 viruses with 50% inhibitory concentrations ranging from 1.0 to 30.9 nM. We have studied anti-HIV-1 interactions of SCH-C with other antiretroviral agents in vitro. Synergistic interactions were seen with nucleoside reverse transcriptase inhibitors (zidovudine and lamivudine), nonnucleoside reverse transcriptase inhibitors (efavirenz), and protease inhibitors (indinavir) at all inhibitory concentrations evaluated. We have also studied antiviral interactions between the HIV-1 fusion inhibitor T-20 and SCH-C against a panel of R5 HIV-1 isolates. We found synergistic interactions against all the viruses tested, some of which harbored resistance mutations to reverse transcriptase and protease inhibitors. Anti-HIV-1 synergy was also observed between SCH-C and another R5 virus inhibitor, aminooxypentane-RANTES. These findings suggest that SCH-C may be a useful anti-HIV drug in combination regimens and that a combination of chemokine coreceptor/fusion inhibitors may be useful in the treatment of multidrug-resistant viruses.

1998 ◽  
Vol 9 (5) ◽  
pp. 412-421 ◽  
Author(s):  
C Chamorro ◽  
M-J Camarasa ◽  
M-J Pérez-Pérez ◽  
E de Clercq ◽  
J Balzarini ◽  
...  

Novel derivatives of the potent human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitor TSAO-T have been designed, synthesized and tested for their in vitro antiretro-viral activity against HIV. These TSAO-T derivatives have been designed as potential bidentate inhibitors of HIV-1 RT, which combine in their structure the functionality of a non-nucleoside RT inhibitor (TSAO-T) and a bivalent ion-chelating moiety (a β-diketone moiety) linked through an appropriate spacer to the N-3 of thymine of TSAO-T . Some of the new compounds have an anti-HIV-1 activity comparable to that of the parent compound TSAO-T, but display a markedly increased antiviral selectivity. There was a clear relationship between antiviral activity and the length of the spacer group that links the TSAO molecule with the chelating moiety. A shorter spacer invariably resulted in increased antiviral potency. None of the TSAO-T derivatives were endowed with anti-HIV-2 activity.


2007 ◽  
Vol 51 (9) ◽  
pp. 3147-3154 ◽  
Author(s):  
Richard Hazen ◽  
Robert Harvey ◽  
Robert Ferris ◽  
Charles Craig ◽  
Phillip Yates ◽  
...  

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.


1998 ◽  
Vol 42 (3) ◽  
pp. 618-623 ◽  
Author(s):  
M. Witvrouw ◽  
M. E. Arranz ◽  
C. Pannecouque ◽  
R. Declercq ◽  
H. Jonckheere ◽  
...  

ABSTRACT We report the development of a new group of nonnucleoside reverse transcriptase inhibitors (NNRTIs). One of the most active congeners of this series of 1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazine (TTD) derivatives, i.e., 2-(3-fluorobenzyl)-4-cyanomethylen-1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazine) (QM96639) was found to inhibit human immunodeficiency virus (HIV) type 1 [HIV-1 (IIIB)] replication in MT-4 cells at a concentration of 0.09 μM. This compound was toxic for the host cells only at a 1,400-fold higher concentration. The TTD derivatives proved effective against a variety of HIV-1 strains, including those that are resistant to 3′-azido-3′-deoxythymidine (AZT), but not against HIV-2 (ROD) or simian immunodeficiency virus (SIV/MAC251). HIV-1 strains containing the L100I, K103N, V106A, E138K, Y181C, or Y188H mutations in their reverse transcriptase (RT) displayed reduced sensitivity to the compounds. Their cross-resistance patterns correlated with that of nevirapine. 2-Benzyl-4-cyanomethylen-1,1,3-trioxo-2H,4H-thieno[3,4-e][1,2,4]thiadiazine (QM96521) enhanced the anti-HIV-1 activity of AZT and didanosine in a subsynergistic manner. HIV-1-resistant virus containing the V179D mutation in the RT was selected after approximately six passages of HIV-1 (IIIB) in CEM cells in the presence of different concentrations of QM96521. From structure-activity relationship analysis of a wide variety of TTD derivatives, a number of restrictions appeared as to the chemical modifications that were compatible with anti-HIV activity. Modelling studies suggest that in contrast to most other NNRTIs, but akin to nevirapine, QM96521 does not act as a hydrogen bond donor in the RT-drug complex.


1997 ◽  
Vol 8 (3) ◽  
pp. 197-204 ◽  
Author(s):  
J Balzarini ◽  
E De Clercq

The thiocarboxanilides represent a structural class of potent and selective human immunodeficiency virus type 1 (HIV-1)-specific reverse transcriptase (RT) inhibitors. Combinations of the clinical candidate thiocarboxanilides UC-10 (oxime ether derivative) and UC-781 (pentenyloxy ether derivative) with a variety of nucleoside RT inhibitors (NRTIs) and non-nucleoside RT inhibitors (NNRTIs), two HIV protease inhibitors and one fusion/uncoating inhibitor were evaluated for their inhibitory effects on HIV-1 RT activity and HIV-1 replication in CEM cell cultures. The inhibitory activity of the NNRTIs including UC-10, UC-781, nevirapine, BHAR α-APA, 8-chloro-TIBO, MKC-442 and the quinoxaline HBY 097 against HIV-1 RT was highly dependent on the nature of the template/primer used in the HIV-1 RT reaction. However, fractionary inhibitory concentration (FIC) indexes for all drug concentrations evaluated in the combination experiments of UC-781 and the other NNRTIs fell within the range 0.5–1.5. This points to a predominantly additive effect of the thiocarboxanilides and other NNRTIs in the inhibition of HIV-1 RT. Similar FIC indexes were observed for the combination of UC-781 with the NRTI triphosphates AZT-TP, d4T-TP, ddCTP, ddATP and 3TC-TP and the NRTI diphosphate PMEApp against HIV-1 RT. All these drug combinations showed similar additive inhibitory effects on HIV-1 replication in cell culture. Also, the combinations of UC-10 or UC-781 with the protease inhibitors Ro31–8959/008 and ABT 84538.0 and the fusion/uncoating inhibitor bicyclam JM 3100 showed an additive effect (FIC within the 0.5–1.5 range). Thus, irrespective of the nature of the drugs, their combination with the thiocarboxanilides proved merely additive. In no case were antagonistic anti-HIV activity or increased cytotoxicity observed. In conclusion, thiocarboxanilides combined with a variety of clinically used anti-HIV agents result in additive anti-HIV activity.


1998 ◽  
Vol 42 (12) ◽  
pp. 3123-3129 ◽  
Author(s):  
Veronica Miller ◽  
Marie-Pierre de Béthune ◽  
Astrid Kober ◽  
Martin Stürmer ◽  
Kurt Hertogs ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) strains resistant to nonnucleoside reverse transcriptase inhibitors (NNRTIs) may easily be selected for in vitro and in vivo under a suboptimal therapy regimen. Although cross-resistance is extensive within this class of compounds, newer NNRTIs were reported to retain activity against laboratory strains containing defined resistance-associated mutations. We have characterized HIV-1 resistance to loviride and the extent of cross-resistance to nevirapine, delavirdine, efavirenz, HBY-097, and tivirapine in a set of 24 clinical samples from patients treated with long-term loviride monotherapy by using a recombinant virus assay. Genotypic changes associated with resistance were analyzed by population sequencing. Overall, phenotypic resistance to loviride ranged from 0.04 to 3.47 log10-fold. Resistance was observed in samples from patients who had discontinued loviride for up to 27 months. Cross-resistance to the other compounds was extensive; however, fold resistance to efavirenz was significantly lower than fold resistance to nevirapine. No genotypic changes were detected in three samples; these were sensitive to all of the NNRTIs tested. The most common genotypic change was the K103N substitution. The range of phenotypic resistance in samples containing the K103N substitution could not be predicted from a genotypic analysis of known NNRTI resistance-associated mutations. The Y181C substitution was detected in one isolate which was resistant to loviride and delavirdine but sensitive to efavirenz, HBY-097, and tivirapine. Our data indicate that the available newer NNRTIs which retain activity against some HIV-1 strains selected by other compounds of this class in vitro may have compromised clinical efficacy in some patients pretreated with NNRTI.


2003 ◽  
Vol 47 (11) ◽  
pp. 3644-3646 ◽  
Author(s):  
Cécile L. Tremblay ◽  
Danielle L. Poulin ◽  
Jennifer L. Hicks ◽  
Subajini Selliah ◽  
Annie Chamberland ◽  
...  

ABSTRACT We evaluated the in vitro anti-human immunodeficiency virus type 1 (HIV-1) interactions between 1- β-d-2,6-diaminopurine dioxolane (DAPD) and enfuvirtide (T-20) against clinical isolates sensitive and resistant to reverse transcriptase and protease inhibitors. Interactions between T-20 and DAPD were synergistic to nearly additive, with combination index values ranging from 0.53 to 1.06 at 95% inhibitory concentrations. These studies suggest that a combination of T-20 and DAPD might be useful in the treatment of antiretroviral drug-experienced patients.


2008 ◽  
Vol 52 (6) ◽  
pp. 2111-2119 ◽  
Author(s):  
Hirotomo Nakata ◽  
Seth M. Steinberg ◽  
Yasuhiro Koh ◽  
Kenji Maeda ◽  
Yoshikazu Takaoka ◽  
...  

ABSTRACT Aplaviroc (AVC), an experimental CCR5 inhibitor, potently blocks in vitro the infection of R5-tropic human immunodeficiency virus type 1 (R5-HIV-1) at subnanomolar 50% inhibitory concentrations. Although maraviroc is presently clinically available, further studies are required to determine the role of CCR5 inhibitors in combinations with other drugs. Here we determined anti-HIV-1 activity using combinations of AVC with various anti-HIV-1 agents, including four U.S. Food and Drug Administration-approved drugs, two CCR5 inhibitors (TAK779 and SCH-C) and two CXCR4 inhibitors (AMD3100 and TE14011). Combination effects were defined as synergistic or antagonistic when the activity of drug A combined with B was statistically greater or less, respectively, than the additive effects of drugs A and A combined and drugs B and B combined by using the Combo method, described in this paper, which provides (i) a flexible choice of interaction models and (ii) the use of nonparametric statistical methods. Synergistic effects against R5-HIV-1Ba-L and a 50:50 mixture of R5-HIV-1Ba-L and X4-HIV-1ERS104pre (HIV-1Ba-L/104pre) were seen when AVC was combined with zidovudine, nevirapine, indinavir, or enfuvirtide. Mild synergism and additivity were observed when AVC was combined with TAK779 and SCH-C, respectively. We also observed more potent synergism against HIV-1Ba-L/104pre when AVC was combined with AMD3100 or TE14011. The data demonstrate a tendency toward greater synergism with AVC plus either of the two CXCR4 inhibitors compared to the synergism obtained with combinations of AVC and other drugs, suggesting that the development of effective CXCR4 inhibitors may be important for increasing the efficacies of CCR5 inhibitors.


1999 ◽  
Vol 43 (10) ◽  
pp. 2376-2382 ◽  
Author(s):  
Zhengxian Gu ◽  
Mark A. Wainberg ◽  
Nghe Nguyen-Ba ◽  
Lucille L’Heureux ◽  
Jean-Marc de Muys ◽  
...  

ABSTRACT (−)-β-d-1′,3′-Dioxolane guanosine (DXG) and 2,6-diaminopurine (DAPD) dioxolanyl nucleoside analogues have been reported to be potent inhibitors of human immunodeficiency virus type 1 (HIV-1). We have recently conducted experiments to more fully characterize their in vitro anti-HIV-1 profiles. Antiviral assays performed in cell culture systems determined that DXG had 50% effective concentrations of 0.046 and 0.085 μM when evaluated against HIV-1IIIB in cord blood mononuclear cells and MT-2 cells, respectively. These values indicate that DXG is approximately equipotent to 2′,3′-dideoxy-3′-thiacytidine (3TC) but 5- to 10-fold less potent than 3′-azido-2′,3′-dideoxythymidine (AZT) in the two cell systems tested. At the same time, DAPD was approximately 5- to 20-fold less active than DXG in the anti-HIV-1 assays. When recombinant or clinical variants of HIV-1 were used to assess the efficacy of the purine nucleoside analogues against drug-resistant HIV-1, it was observed that AZT-resistant virus remained sensitive to DXG and DAPD. Virus harboring a mutation(s) which conferred decreased sensitivity to 3TC, 2′,3′-dideoxyinosine, and 2′,3′-dideoxycytidine, such as a 65R, 74V, or 184V mutation in the viral reverse transcriptase (RT), exhibited a two- to fivefold-decreased susceptibility to DXG or DAPD. When nonnucleoside RT inhibitor-resistant and protease inhibitor-resistant viruses were tested, no change in virus sensitivity to DXG or DAPD was observed. In vitro drug combination assays indicated that DXG had synergistic antiviral effects when used in combination with AZT, 3TC, or nevirapine. In cellular toxicity analyses, DXG and DAPD had 50% cytotoxic concentrations of greater than 500 μM when tested in peripheral blood mononuclear cells and a variety of human tumor and normal cell lines. The triphosphate form of DXG competed with the natural nucleotide substrates and acted as a chain terminator of the nascent DNA. These data suggest that DXG triphosphate may be the active intracellular metabolite, consistent with the mechanism by which other nucleoside analogues inhibit HIV-1 replication. Our results suggest that the use of DXG and DAPD as therapeutic agents for HIV-1 infection should be explored.


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