ABSTRACT: Lersivirine is a nonnucleoside reverse transcriptase inhibitor undergoing clinical development for the treatment of HIV-1.
The goal of this study was to investigate the safety and tolerability of multiple oral doses of lersivirine administered to healthy male subjects to assist in the planning of longer term studies.
This was a randomized, double-blind, double-dummy, placebo-controlled, parallel-group, multicenter, Phase I clinical study in fasting, healthy male volunteers. Subjects were randomly assigned in a ratio of 7:7:4:4 to receive lersivirine 500 mg BID, lersivirine 750 mg once daily, efavirenz 600 mg once daily, or placebo once daily for 28 days. Safety and tolerability were assessed throughout the study by continuous collection of adverse events (AEs), including adverse drug reactions, illnesses with onset during the study, exacerbation of previous illnesses, and clinically significant changes in physical examination findings. Vital sign measurements and ECGs were performed at screening; on day 1 (predose and 2, 3, and 4 hours postdose); on days 7, 14, 21, and 28 (predose); at discharge; and at follow-up. Safety laboratory tests (including hematology, chemistry, and urinalysis) were performed at screening; days 0, 7, 14, 21, and 27; and at follow-up.
Of the 66 healthy male subjects enrolled (age range, 21-51 years; body mass index, 18.1-29.9 kg/m(2)), 40 were white, 22 were Asian, 3 were black, and 1 was of mixed race. There were no clinically significant laboratory abnormalities, including changes in lipid profile, liver or renal function test results, or ECG findings. Overall, 86% (18/21) of subjects in the lersivirine 500-mg BID group, 81% (17/21) in the lersivirine 750-mg once-daily group, 92% (11/12) in the efavirenz 600-mg once-daily group, and 92% (11/12) in the placebo group experienced at least one treatment-related AE. Eight subjects were permanently discontinued from the study; 4 subjects in the efavirenz group (3 of whom participated in the trial at the Brussels study center) were permanently discontinued due to AEs considered to be treatment related. No subjects receiving lersivirine permanently discontinued the study due to treatment-related AEs, although one subject temporarily discontinued treatment. In addition, 4 subjects withdrew consent (2 subjects [1 of whom was at the Brussels study center] receiving lersivirine 750 mg once daily and 2 subjects [1 of whom was at the Brussels study center] receiving efavirenz). There were no deaths or serious AEs in any of the study groups.
Lersivirine appeared to be well tolerated after 28 days of continuous dosing in this small, selected group of young, healthy male volunteers.
Clinical Therapeutics 10/2010; 32(11):1889-95. · 2.32 Impact Factor
ABSTRACT: The MERIT (Maraviroc versus Efavirenz in Treatment-Naive Patients) study compared maraviroc and efavirenz, both with zidovudine-lamivudine, in antiretroviral-naive patients with R5 human immunodeficiency virus type 1 (HIV-1) infection.
Patients screened for R5 HIV-1 were randomized to receive efavirenz (600 mg once daily) or maraviroc (300 mg once or twice daily) with zidovudine-lamivudine. Coprimary end points were proportions of patients with a viral load <400 and <50 copies/mL at week 48; the noninferiority of maraviroc was assessed.
The once-daily maraviroc arm was discontinued for not meeting prespecified noninferiority criteria. In the primary 48-week analysis (n = 721), maraviroc was noninferior for <400 copies/mL (70.6% for maraviroc vs 73.1% for efavirenz) but not for <50 copies/mL (65.3% vs 69.3%) at a threshold of -10%. More maraviroc patients discontinued for lack of efficacy (11.9% vs 4.2%), but fewer discontinued for adverse events (4.2% vs 13.6%). In a post hoc reanalysis excluding 107 patients (15%) with non-R5 screening virus by the current, more sensitive tropism assay, the lower bound of the 1-sided 97.5% confidence interval for the difference between treatment groups was above -10% for each end point.
Twice-daily maraviroc was not noninferior to efavirenz at <50 copies/mL in the primary analysis. However, 15% of patients would have been ineligible for inclusion by a more sensitive screening assay. Their retrospective exclusion resulted in similar response rates in both arms Trial registration. ClinicalTrials.gov identifier: (NCT00098293) .
The Journal of Infectious Diseases 02/2010; 201(6):803-13. · 6.41 Impact Factor
ABSTRACT: To investigate the effects on viral load and assess dose-response relationships, pharmacokinetics, safety and tolerability of lersivirine (UK-453,061), a next-generation nonnucleoside reverse transcriptase inhibitor, in asymptomatic HIV-1-infected patients.
Randomized, double-blind, placebo-controlled, parallel group, multicenter phase IIa clinical study.
Forty-eight HIV-1-infected patients were enrolled for the study of once-daily or twice-daily lersivirine at total daily doses ranging from 20 to 1000 mg. The primary endpoint was the change in log10 plasma HIV-1 RNA viral load from baseline to day 8. Secondary endpoints related to pharmacokinetics, safety and tolerability and potential development of viral resistance and genotyping patterns.
Patients treated with lersivirine achieved day 8 mean viral load reductions of 0.3, 0.8, 1.3 and 1.6 log10 after receiving 10, 30, 100 and 500 mg twice daily, respectively, and 0.9, 1.7 and 1.8 log10 after receiving 100, 500 and 750 mg once daily, respectively. Mean changes from baseline to day 8 were small in patients receiving placebo. For all dose regimens, plasma exposure increased approximately in line with lersivirine dose. Median plasma concentrations of lersivirine at steady state were above the IC90 for lersivirine at once-daily doses of at least 500 mg and twice-daily doses of at least 100 mg. The most commonly reported treatment-emergent adverse events were headache, fatigue and nausea.
Seven-day monotherapy with lersivirine achieved mean viral load reductions up to 1.8 log10. Lersivirine was safe and well tolerated. Further studies of lersivirine in combination with other antiretroviral drugs to assess long-term durability of antiviral response, safety and tolerability are warranted.
AIDS (London, England) 09/2009; 23(16):2115-22. · 4.91 Impact Factor
ABSTRACT: To assess the effect of a single dose of maraviroc on the QTc interval in healthy subjects and to evaluate the QTc interval-concentration relationship.
A single-dose, placebo- and active-controlled, five-way crossover study was conducted to investigate the effects of maraviroc (100, 300, 900 mg) on QTc in healthy subjects. Moxifloxacin (400 mg) was used as the active comparator. The study was double-blind with respect to maraviroc/placebo and open label for moxifloxacin. There was a 7-day wash-out period between each dose. QT interval measurements obtained directly from the electrocardiogram (ECG) recorder were corrected for heart rate using Fridericia's correction (QTcF). A placebo run-in day was conducted before period 3, when ECGs were collected at intervals while subjects were resting or during exercise. These ECGs plus other predose ECGs were used to evaluate the QT/RR relationship for each subject to enable calculation of an individual's heart rate correction for their QT measurements (QTcI). ECGs were taken at various intervals pre- and postdose in each study period. Pharmacokinetic parameters were determined for each maraviroc dose. The end-points that were evaluated were QTcF at median time to maximum concentration (T(max)) based on the machine readings and QTcI at median T(max) based on manual over-reads of the QT/RR data. A separate analysis of variance was used for each of the pair-wise comparisons for each end-point. The relationship between QTc interval and plasma concentration was also investigated using a mixed-effects modelling approach, as implemented by the NONMEM software system. A one-stage model was employed in which the relationship between QT and RR and the effects of maraviroc plasma concentration on QT were estimated simultaneously.
The mean difference from placebo in machine-read QTcF at median T(max) for maraviroc 900 mg was 3.6 ms [90% confidence interval (CI) 1.5, 5.8]. For the active comparator, moxifloxacin, the mean difference from placebo in machine-read QTcF was 13.7 ms. The changes from placebo for each of the end-points were similar for men and women. No subjects receiving maraviroc or placebo had a QTcF > or = 450 ms (men) or QTcF > or = 470 ms (women), nor did any subject experience a QTcF increase > or = 60 ms from baseline at any time point. Analysis based on the QTcI data obtained from the manual over-readings of the ECGs gave numerically very similar results. The QT:RR relationship was similar pre- and postdose and was not related to maraviroc concentration. The population estimate of the QT:RR correction factor was 0.324 (95% CI 0.309, 0.338). The population estimate of the slope describing the QT-concentration relationship was 0.97 micros ml ng(-1) (95% CI -0.571, 2.48), equivalent to an increase of 0.97 ms in QT per 1000 ng maraviroc plasma concentration. Most adverse events were mild to moderate in severity.
Single doses of maraviroc, up to and including 900 mg, had no clinically relevant effect on QTcF or QTcI. At all maraviroc doses and for both end-points, the mean difference from placebo for QTc was < 4 ms. There was no apparent relationship between QT interval and maraviroc plasma concentration up to 2363 ng ml(-1). This conclusion held in both male and female subjects, and there was no evidence of a change in the QT/RR relationship with concentration.
British Journal of Clinical Pharmacology 04/2008; 65 Suppl 1:68-75. · 2.96 Impact Factor