de Bethune M.-P.,Tibotec BVBA
Antiviral Research | Year: 2010
It is almost 20 years since NNRTIs were identified as a new class of antiretroviral drugs for the treatment of HIV-1 infection. Although they belong to different and diverse chemical families, they share a common and unique mechanism of action: their interaction with HIV-1 reverse transcriptase induces conformational changes that inhibit the catalytic activities of the enzyme. They are characterized by their specificity for HIV-1, which makes them very selective inhibitors of the virus. First generation NNRTIs nevirapine and efavirenz, in combination with other antiretroviral drugs, have become a cornerstone for the treatment of HIV-1 infection, in patients initiating antiretroviral therapy. Further research has led to the discovery and development of next generation NNRTIs with an increased genetic barrier to the development of resistance. Etravirine is the first NNRTI to show sustained virologic efficacy in patients with NNRTI resistant HIV-1. This review covers the NNRTI class of anti-HIV-1 drugs, from the initial discovery of the class in 1990 to the current compounds in clinical development, i.e. around 20 years of research and development efforts. It describes the characteristics of the NNRTIs, their mechanisms of action, HIV-1 resistance to the inhibitors, and the drugs that have been approved for the treatment of HIV-1 infection, or are currently in clinical development. The role of NNRTIs in prevention of HIV transmission is also addressed. This article forms part of a special issue of Antiviral Research marking the 25th anniversary of antiretroviral drug discovery and development, vol. 85, issue 1, 2010. © 2009 Elsevier B.V. All rights reserved.
Zhang T.,Johns Hopkins University |
Zhang T.,CAS Guangzhou Institute of Biomedicine and Health |
Li S.-Y.,Johns Hopkins University |
Williams K.N.,Johns Hopkins University |
And 2 more authors.
American Journal of Respiratory and Critical Care Medicine | Year: 2011
Rationale: Multidrug-resistant and extensively drug-resistant tuberculosis (MDR/XDR-TB) is an emerging global health threat. Proper management of close contacts of infectious patients is increasingly important. However, no evidence-based recommendations for treating latent TB infection (LTBI) after MDR/XDR-TB exposure (DR-LTBI) exist. An ultrashort regimen for LTBI caused by drug-susceptible strains (DS-LTBI) is also desirable. TMC207 has bactericidal and sterilizing activity in animal models of TB and improves the activity of current MDR-TB therapy in patients. Objectives: The objective of this study was to determine whether TMC207 might enable short-course treatment of DR-LTBI and ultra-short treatment of DS-LTBI. Methods: Using an established experimental model of LTBI chemotherapy in which mice are aerosol-immunized with a recombinant bacillus Calmette-Guérin vaccine before low-dose aerosol infection with Mycobacterium tuberculosis, the efficacy of TMC207 alone and in combination with rifapentine was compared with currently recommended control regimens as well as once-weekly rifapentine 1 isoniazid and daily rifapentine 6 isoniazid. Measurements: Outcomes included monthly lung colony-forming unit counts and relapse rates. Main Results: Lung colony-forming unit counts were stable at about 3.75 log 10 for up to 7.5 months postinfection in untreated mice. Rifamycin-containing regimens were superior to isoniazid monotherapy. TMC207 exhibited sterilizing activity at least as strong as that of rifampin alone and similar to that of rifampin 1 isoniazid, but daily rifapentine 1/2 isoniazid was superior to TMC207. Addition of TMC207 to rifapentine did not improve the sterilizing activity of rifapentine in this model. Conclusions: TMC207 has substantial sterilizing activity and may enable treatment of DR-LTBI in 3-4 months.
Rimsky L.,Tibotec BVBA |
Vingerhoets J.,Tibotec BVBA |
Van Eygen V.,Tibotec BVBA |
Eron J.,University of North Carolina at Chapel Hill |
And 4 more authors.
Journal of Acquired Immune Deficiency Syndromes | Year: 2012
Genotypic and phenotypic characterization was performed of HIV-1 isolates from treatment-naive HIV-1-infected patients experiencing virologic failure (VF) during treatment with the nonnucleoside reverse transcriptase inhibitor (NNRTIs) rilpivirine or efavirenz in the pooled phase 3 studies ECHO and THRIVE. Among 686 patients receiving rilpivirine, 72 (10%) experienced VF versus 39 of 682 (6%) receiving efavirenz. In patients with low baseline viral load (VL) ≤100,000 copies per milliliter, the proportions of rilpivirine VFs (19 of 368) and efavirenz VFs (16 of 330) were the same (5%). In patients with high baseline VL >100,000 copies per milliliter, the proportion of VFs was higher with rilpivirine (53 of 318; 17%) than efavirenz (23 of 352; 7%). The rate of rilpivirine VF was comparable between HIV-1 subtype B-infected (11%) and nonsubtype B-infected (8%) patients. The absolute number of VFs with treatment-emergent NNRTI resistance-associated mutations (RAMs) was higher for rilpivirine (most commonly E138K or K101E) than efavirenz (most commonly K103N), but relative proportions were similar [63% (39 of 62) vs. 54% (15 of 28), respectively]. More rilpivirine VFs had treatment-emergent nucleoside/nucleotide reverse transcriptase inhibitor RAMs than efavirenz VFs [68% (42 of 62) versus 32% (9 of 28), respectively], most commonly M184I and M184V. The proportion of rilpivirine VFs with RAMs in patients with low baseline VL was lower than in those with high baseline VL [38% (6 of 16) versus 72% (33 of 46) for NNRTI RAMs and 44% (7 of 16) versus 76% (35 of 46) for nucleoside/nucleotide reverse transcriptase inhibitor RAMs, respectively]. In summary, VF and treatment-emergent reverse transcriptase RAMs were similar at low baseline VL but more frequent at high baseline VL in rilpivirine-treated than in efavirenz-treated patients. The frequent emergence of E138K, especially in combination with M184I, in rilpivirine VFs is a unique finding of these trials.
Kakuda T.N.,Tibotec Inc. |
Scholler-Gyure M.,Tibotec BVBA |
Hoetelmans R.M.W.,Tibotec BVBA
Clinical Pharmacokinetics | Year: 2011
Etravirine (formerly TMC125) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) with activity against wild-type and NNRTI-resistant strains of HIV-1. Etravirine has been approved in several countries for use as part of highly active antiretroviral therapy in treatment-experienced patients.In vivo, etravirine is a substrate for, and weak inducer of, the hepatic cytochrome P450 (CYP) isoenzyme 3A4 and a substrate and weak inhibitor of CYP2C9 and CYP2C19. Etravirine is also a weak inhibitor of P-glycoprotein. An extensive drug-drug interaction programme in HIV-negative subjects has been carried out to assess the potential for pharmacokinetic interactions between etravirine and a variety of non-antiretroviral drugs.Effects of atorvastatin, clarithromycin, methadone, omeprazole, oral contraceptives, paroxetine, ranitidine and sildenafil on the pharmacokinetic disposition of etravirine were of no clinical relevance. Likewise, etravirine had no clinically significant effect on the pharmacokinetics of fluconazole, methadone, oral contraceptives, paroxetine or voriconazole. No clinically relevant interactions are expected between etravirine and azithromycin or ribavirin, therefore, etravirine can be combined with these agents without dose adjustment.Fluconazole and voriconazole increased etravirine exposure 1.9- and 1.4-fold, respectively, in healthy subjects, however, no increase in the incidence of adverse effects was observed in patients receiving etravirine and fluconazole during clinical trials, therefore, etravirine can be combined with these antifungals although caution is advised.Digoxin plasma exposure was slightly increased when co-administered with etravirine. No dose adjustments of digoxin are needed when used in combination with etravirine, however, it is recommended that digoxin levels should be monitored. Caution should be exercised in combining rifabutin with etravirine in the presence of certain boosted HIV protease inhibitors due to the risk of decreased exposure to etravirine. Although adjustments to the dose of clarithromycin are unnecessary for the treatment of most infections, the use of an alternative macrolide (e.g. azithromycin) is recommended for the treatment of Mycobacterium avium complex infection since the overall activity of clarithromycin against this pathogen may be altered when co-administered with etravirine. Dosage adjustments based on clinical response are recommended for clopidogrel, HMG-CoA reductase inhibitors (e.g. atorvastatin) and for phosphodiesterase type-5 inhibitors (e.g. sildenafil) because changes in the exposure of these medications in the presence of co-administered etravirine may occur.When co-administered with etravirine, a dose reduction or alternative to diazepam is recommended. When combining etravirine with warfarin, the international normalized ratio (INR) should be monitored. Systemic dexamethasone should be co-administered with caution, or an alternative to dexamethasone be found as dexamethasone induces CYP3A4. Caution is also warranted when co-administering etravirine with some antiarrhythmics, calcineurin inhibitors (e.g. ciclosporin) and antidepressants (e.g. citalopram). Co-administration of etravirine with some antiepileptics (e.g. carbamazepine and phenytoin), rifampicin (rifampin), rifapentine or preparations containing St Johns wort (Hypericum perforatum) is currently not recommended as these are potent inducers of CYP3A andor CYP2C and may potentially decrease etravirine exposure. Antiepileptics that are less likely to interact based on their known pharmacological properties include gabapentin, lamotrigine, levetiracetam and pregabalin.Overall, pharmacokinetic and clinical data show etravirine to be well tolerated and generally safe when given in combination with non-antiretroviral agents, with minimal clinically significant drug interactions and no need for dosage adjustments of etravirine in any of the cases, or of the non-antiretroviral agent in the majority of cases studied. © 2011 Adis Data Information BV. All rights reserved.
Andries K.,Tibotec BVBA |
Gevers T.,Tibotec BVBA |
Lounis N.,Tibotec BVBA
Antimicrobial Agents and Chemotherapy | Year: 2010
TMC207, rifapentine, and moxifloxacin are in clinical testing for the treatment of tuberculosis. Five experimental regimens with various combinations of TMC207, rifapentine, moxifloxacin, and pyrazinamide were tested for their bactericidal and sterilizing potencies in Swiss mice intravenously inoculated with Mycobacterium tuberculosis bacilli. TMC207 had the strongest bactericidal efficacy, while rifapentine was the strongest contributor to sterilizing efficacy. The rank order of sterilizing potencies was different from the rank order of bactericidal potencies, underlining the importance of prioritizing new regimens designed to shorten the treatment duration by their sterilizing potencies rather than by their bactericidal potencies. Both 3 months of treatment with a regimen combining TMC207, pyrazinamide, and rifapentine and 5 months of treatment with a regimen combining TMC207, pyrazinamide, and moxifloxacin resulted in relapse rates similar to the rate obtained by 6 months of treatment with rifampin-isoniazid-pyrazinamide. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Kakuda T.N.,Tibotec Inc. |
Scholler-Gyure M.,Tibotec BVBA |
Hoetelmans R.M.W.,Tibotec BVBA
Antiviral Therapy | Year: 2010
Etravirine is an effective and well-tolerated recently approved non-nucleoside reverse transcriptase inhibitor (NNRTI) for HIV type-1-infected patients with previous antiretroviral treatment experience. Considering the importance of combining antiretrovirals for their optimal use in treating HIV, a number of drug-drug interactions with etravirine and other antiretrovirals have been evaluated. Etravirine is a weak inducer of cytochrome P450 (CYP)3A and a weak inhibitor of CYP2C9/CYP2C19 and P-glycoprotein, and although etravirine is metabolized by the CYP enzyme system, the extent of clinically relevant interactions with other antiretrovirals is limited. Etravirine can be combined with all currently available nucleoside/nucleotide reverse transcriptase inhibitors without dose adjustments, but not with other NNRTIs. Available data indicate that etravirine can be coadministered with most of the currently available ritonavir-boosted HIV protease inhibitors. Coadministration with tipranavir/ritonavir or unboosted HIV protease inhibitors is not recommended because of clinically relevant changes in exposure to etravirine or the coadministered HIV protease inhibitor, respectively. Etravirine can be coadministered with the integrase inhibitors elvitegravir/ritonavir or raltegravir, and with the fusion inhibitor enfuvirtide, without dose adjustments. Dose adjustment of the C-C chemokine receptor type-5 antagonist maraviroc is required, with the type of adjustment depending on whether a boosted HIV protease inhibitor is included in the regimen. In conclusion, etravirine can be combined with most antiretrovirals, with no clinically meaningful effect on drug exposure or safety/tolerability profiles. ©2010 International Medical Press.
Garg V.,Vertex Pharmaceuticals |
van Heeswijk R.,Tibotec BVBA |
Eun Lee J.,Vertex Pharmaceuticals |
Alves K.,Vertex Pharmaceuticals |
And 2 more authors.
Hepatology | Year: 2011
The hepatitis C virus protease inhibitor telaprevir is an inhibitor of the enzyme cytochrome P450 3A, responsible for the metabolism of both cyclosporine and tacrolimus. This Phase I, open-label, nonrandomized, single-sequence study assessed the effect of telaprevir coadministration on the pharmacokinetics of a single dose of either cyclosporine or tacrolimus in two separate panels of 10 healthy volunteers each. In Part A, cyclosporine was administered alone as a single 100-mg oral dose, followed by a minimum 8-day washout period, and subsequent coadministration of a single 10-mg oral dose of cyclosporine with either a single dose of telaprevir (750 mg) or with steady-state telaprevir (750 mg every 8 hours [q8h]). In Part B, tacrolimus was administered alone as a single 2-mg oral dose, followed by a minimum 14-day washout period, and subsequent coadministration of a single 0.5-mg dose of tacrolimus with steady-state telaprevir (750 mg q8h). Coadministration with steady-state telaprevir increased cyclosporine dose-normalized (DN) exposure (DN-AUC 0-∞) by approximately 4.6-fold and increased tacrolimus DN-AUC 0-∞ by approximately 70-fold. Coadministration with telaprevir increased the terminal elimination half-life (t 1/2) of cyclosporine from a mean (standard deviation [SD]) of 12 (1.67) hours to 42.1 (11.3) hours and t 1/2 of tacrolimus from a mean (SD) of 40.7 (5.85) hours to 196 (159) hours. Conclusion: In this study, telaprevir increased the blood concentrations of both cyclosporine and tacrolimus significantly, which could lead to serious or life-threatening adverse events. Telaprevir has not been studied in organ transplant patients; its use in these patients is not recommended because the required studies have not been completed to understand appropriate dose adjustments needed for safe coadministration of telaprevir with cyclosporine or tacrolimus, and regulatory approval has not been obtained. © 2011 American Association for the Study of Liver Diseases.
Tambuyzer L.,Tibotec BVBA |
Nijs S.,Tibotec BVBA |
Daems B.,Tibotec BVBA |
Picchio G.,Tibotec Inc. |
Vingerhoets J.,Tibotec BVBA
Journal of Acquired Immune Deficiency Syndromes | Year: 2011
The contribution of E138 mutations to etravirine resistance was investigated. Amino acids at position E138 after failure with etravirine in DUET were A (n = 1), G (n = 5), K (n = 3), P (n = 1), Q (n = 5), and V (n = 2). At baseline, only E138A and Q were found at 3.0% and 2.5%, respectively. Virologic response (less than 50 copies/mL) was observed in six of 12 and eight of 10 patients with E138A and E138Q, respectively. Site-directed mutants harboring E138A/G/K/Q/R or S showed etravirine fold change values of 2.9, 2.4, 2.6, 3.0, 3.6, and 2.8, respectively. E138G, K, and Q were added to the existing etravirine-weighted genotypic score including 17 etravirine resistance- associated mutations. Copyright © 2011 Lippincott Williams & Wilkins.
Moors S.L.C.,Catholic University of Leuven |
Vos A.M.,Tibotec BVBA |
Cummings M.D.,Johnson and Johnson Pharmaceutical Research and Development |
Van Vlijmen H.,Tibotec BVBA |
Ceulemans A.,Catholic University of Leuven
Journal of Medicinal Chemistry | Year: 2011
Realistic representation of protein flexibility in biomolecular simulations remains an unsolved fundamental problem and is an active area of research. The high flexibility of the cytochrome P450 2D6 (CYP2D6) active site represents a challenge for accurate prediction of the preferred binding mode and site of metabolism (SOM) for compounds metabolized by this important enzyme. To account for this flexibility, we generated a large ensemble of unbiased CYP2D6 conformations, to which small molecule substrates were docked to predict their experimentally observed SOM. SOM predictivity was investigated as a function of the number of protein structures, the scoring function, the SOM-heme cutoff distance used to distinguish metabolic sites, and intrinsic reactivity. Good SOM predictions for CYP2D6 require information from the protein. A critical parameter is the distance between the heme iron and the candidate site of metabolism. The best predictions were achieved with cutoff distances consistent with the chemistry relevant to CYP2D6 metabolism. Combination of the new ensemble-based docking method with estimated intrinsic reactivities of substrate sites considerably improved the predictivity of the model. Testing on an independent set of substrates yielded area under curve values as high as 0.93, validating our new approach. © 2011 American Chemical Society.
de rijck J.,Laboratory for Molecular Virology and Gene Therapy |
Bartholomeeusen K.,Laboratory for Molecular Virology and Gene Therapy |
Ceulemans H.,Tibotec BVBA |
Debyser Z.,Laboratory for Molecular Virology and Gene Therapy |
Gijsbers R.,Laboratory for Molecular Virology and Gene Therapy
Nucleic Acids Research | Year: 2010
Lens epithelium-derived growth factor/p75 (LEDGF/p75) is a transcriptional coactivator involved in stress response, autoimmune disease, cancer and HIV replication. A fusion between the nuclear pore protein NUP98 and LEDGF/p75 has been found in human acute and chronic myeloid leukemia and association of LEDGF/p75 with mixed-lineage leukemia (MLL)/menin is critical for leukemic transformation. During lentiviral replication, LEDGF/p75 tethers the pre-integration complex to the host chromatin resulting in a bias of integration into active transcription units (TUs). The consensus function of LEDGF/p75 is tethering of cargos to chromatin. In this regard, we determined the LEDGF/p75 chromatin binding profile. To this purpose, we used DamID technology and focused on the highly annotated ENCODE (Encyclopedia of DNA Elements) regions. LEDGF/p75 primarily binds downstream of the transcription start site of active TUs in agreement with the enrichment of HIV-1 integration sites at these locations. We show that LEDGF/p75 binding is not restricted to stress response elements in the genome, and correlation analysis with more than 200 genomic features revealed an association with active chromatin markers, such as H3 and H4 acetylation, H3K4 monomethylation and RNA polymerase II binding. Interestingly, some associations did not correlate with HIV-1 integration indicating that not all LEDGF/p75 complexes on the chromosome are amenable to HIV-1 integration. © The Author(s) 2010. Published by Oxford University Press.