Pharmacokinetics of once-daily etravirine without and with once-daily darunavir/ritonavir in antiretroviral-naive HIV type-1-infected adults
ABSTRACT A pharmacokinetic trial was conducted to evaluate the potential for once-daily etravirine in antiretroviral regimens without and with darunavir/ritonavir.
During this multicentre, open-label, Phase IIa trial, treatment-naive patients aged > or =18 years with HIV type-1 (HIV-1) received etravirine 400 mg once daily with tenofovir disoproxil fumarate/emtricitabine 300/200 mg once daily from days 1-14; on days 15-28, darunavir/ritonavir 800/100 mg once daily was added. On day 29, etravirine was discontinued and patients continued with the other medications to day 42. Serial blood sampling for etravirine pharmacokinetics was performed over 24 h on day 14 and 28; patients fasted for > or =10 h prior to these visits.
Of 23 enrolled patients (male 87%, Caucasian 39%), pharmacokinetic profiles for etravirine were available for 21 and 20 patients on day 14 and 28, respectively. The plasma concentration-time profile and pharmacokinetics for etravirine were unchanged with or without darunavir/ritonavir. The mean maximum plasma concentration (C(max)) was reached 4 h after administration and was 790 and 801 ng/ml on day 14 and 28, respectively; mean area under the plasma concentration-time curve (AUC) from before administration to 24 h after administration was 10,410 ng*h/ml on day 14 and 10,720 ng*h/ml on day 28. In a post-hoc analysis, etravirine C(max) was higher, minimum plasma concentration was lower and AUC was similar when compared with etravirine 200 mg twice daily.
Addition of darunavir/ritonavir to etravirine, all dosed once daily, did not have a clinically significant effect on the pharmacokinetics of etravirine. Findings support further investigation of etravirine 400 mg once daily in HIV-1-infected patients. (Trial registration number NCT00534352.).
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ABSTRACT: 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.Antiviral therapy 01/2010; 15(6):817-29. DOI:10.3851/IMP1652 · 3.02 Impact Factor
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ABSTRACT: Current HIV treatment guidelines emphasize the importance of using an active antiretroviral therapy regimen that produces full virologic suppression and immunologic competence, while at the same time providing patients with a favorable safety profile and limited risk for development of drug resistance. Etravirine (TMC125), a recently approved, non-nucleoside reverse transcriptase inhibitor (NNRTI), has shown durable, superior virologic efficacy over placebo in the Phase III, randomized, double-blind DUET trials in 1,203 treatment-experienced, NNRTI-resistant, HIV-1-infected patients. Statistical significance of responses with etravirine over placebo was maintained through Week 24, 48 and 96, regardless of baseline demographics, baseline disease characteristics or the background regimen used. Etravirine has demonstrated a favorable safety and tolerability profile; the incidence of treatment-emergent adverse events was comparable with placebo in the DUET trials, with the exception of rash. The tolerability profile of etravirine also appears to be favorable in terms of neuropsychiatric and hepatic side effects. The pharmacokinetic profile of twice-daily etravirine minimizes the potential for clinically relevant drug-drug interactions and allows for its use in combination with a wide range of other agents. In addition, etravirine has a high genetic barrier to the development of resistance, further enhancing potential benefit in patients infected with NNRTI-resistant virus. The clinical efficacy and favorable safety profile of etravirine, together with its pharmacokinetic profile and high genetic barrier to resistance, make it a valuable treatment option for a wide range of treatment-experienced HIV-1-infected patients.Current HIV research 10/2010; 8(7):564-76. DOI:10.2174/157016210793499196 · 1.76 Impact Factor
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ABSTRACT: successful long-term treatment of HIV is hindered by development of resistance and providing active regimens for treatment-experienced patients remains challenging. Development of antiretrovirals active against resistant virus, such as the diarylpyrimidine non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine, is important to broaden treatment options to patients who have few available. we summarise pharmacology, pharmacokinetics, drug-drug interactions and clinical data of etravirine based on a PubMed search between 01 January 2003 and 01 September 2010 as well as relevant information from conference proceedings and the latest Summary of Product Characteristics and US Prescribing Information. the reader will gain a comprehensive overview of etravirine clinical pharmacology, drug-drug interactions and mechanism of action. Information regarding efficacy, safety and tolerability in specific patients groups is provided to allow the reader to form an opinion regarding the role of etravirine in clinical practice. etravirine, along with other new antiretrovirals, has widened treatment options for patients with multi-drug resistance. Etravirine is well tolerated with the majority of drug-drug interactions manageable and is effective in triple-class experienced patients. Clinical studies investigating etravirine in treatment-naive patients are ongoing to further clarify its safety and resistance profile.Expert Opinion on Drug Metabolism & Toxicology 12/2010; 6(12):1575-85. DOI:10.1517/17425255.2010.535811 · 2.83 Impact Factor