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Dive into the research topics where Margaret Tawadrous is active.

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Featured researches published by Margaret Tawadrous.


The New England Journal of Medicine | 2008

Subgroup analyses of maraviroc in previously treated R5 HIV-1 infection.

Gerd Fätkenheuer; Mark Nelson; Adriano Lazzarin; Irina Konourina; Andy I. M. Hoepelman; Harry Lampiris; Bernard Hirschel; Pablo Tebas; François Raffi; Benoit Trottier; Nicholaos C. Bellos; Michael S. Saag; David A. Cooper; Mike Westby; Margaret Tawadrous; John F. Sullivan; Caroline E. Ridgway; Michael W. Dunne; Steve Felstead; Howard Mayer; Elna van der Ryst

BACKGROUND We conducted subanalyses of the combined results of the Maraviroc versus Optimized Therapy in Viremic Antiretroviral Treatment-Experienced Patients (MOTIVATE) 1 and MOTIVATE 2 studies to better characterize the efficacy and safety of maraviroc in key subgroups of patients. METHODS We analyzed pooled data from week 48 from the two studies according to sex, race or ethnic group, clade, CC chemokine receptor 5 (CCR5) delta32 genotype, viral load at the time of screening, the use or nonuse of enfuvirtide in optimized background therapy (OBT), the baseline CD4 cell count, the number of active antiretroviral drugs coadministered, the first use of selected background agents, and tropism at baseline. Changes in viral tropism and the CD4 count at treatment failure were evaluated. Data on aminotransferase levels in patients coinfected with hepatitis B virus (HBV) or hepatitis C virus (HCV) were also analyzed. RESULTS A treatment benefit of maraviroc plus OBT over placebo plus OBT was shown in all subgroups, including patients with a low CD4 cell count at baseline, those with a high viral load at screening, and those who had not received active agents in OBT. Analyses of the virologic response according to the first use of selected background drugs showed the additional benefit of adding a potent new drug to maraviroc at the initiation of maraviroc therapy. More patients in whom maraviroc failed had a virus binding to the CXC chemokine receptor 4 (CXCR4) at failure, but there was no evidence of a decrease in the CD4 cell count at failure in such patients as compared with those in whom placebo failed. Subanalyses involving patients coinfected with HBV or HCV revealed no evidence of excess hepatotoxic effects as compared with baseline. CONCLUSIONS Subanalyses of pooled data from week 48 indicate that maraviroc provides a valuable treatment option for a wide spectrum of patients with R5 HIV-1 infection who have been treated previously. (ClinicalTrials.gov numbers, NCT00098306 and NCT00098722.)


The Journal of Infectious Diseases | 2010

Maraviroc versus Efavirenz, Both in Combination with Zidovudine-Lamivudine, for the Treatment of Antiretroviral-Naive Subjects with CCR5-tropic HIV-1 Infection

David A. Cooper; Jayvant Heera; James Goodrich; Margaret Tawadrous; Michael S. Saag; Edwin DeJesus; Nathan Clumeck; Sharon Walmsley; Naitee Ting; Eoin Coakley; Jacqueline D. Reeves; Gustavo Reyes-Terán; Mike Westby; Elna van der Ryst; Prudence Ive; Lerato Mohapi; Horacio Mingrone; Andrzej Horban; Frances Hackman; John F. Sullivan; Howard Mayer

BACKGROUND 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. METHODS 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. RESULTS 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. CONCLUSIONS 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) .


Otolaryngology-Head and Neck Surgery | 2005

Efficacy and Safety of a Novel, Single-dose Azithromycin Microsphere Formulation Versus 10 Days of Levofloxacin for the Treatment of Acute Bacterial Sinusitis in Adults

John J. Murray; Paz Emparanza; Eugenijus Lesinskas; Margaret Tawadrous; Jeanne D. Breen

Objective To compare the efficacy and safety of a single 2.0-g dose of a novel azithromycin microsphere formulation with that of 10 days of levofloxacin, 500 mg/d, when used to treat adults with uncomplicated acute bacterial maxillary sinusitis (ABS). Study Design and Setting An international, multicenter, randomized, double-blind, double-dummy trial. Eligible outpatients ≥18 years of age with clinical and radiographic evidence of ABS underwent maxillary sinus aspiration before randomization. Primary endpoint was clinical efficacy at the test-of-cure visit (day 17-24). Results Clinical success rates were 94.5% (242/256) in azithromycin-microspheres-treated patients and 92.8% (233/251) in the levofloxacin group. In patients with documented Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis, clinical cure rates were 97.3% (36/37), 96.3% (26/27), and 100% (8/8), respectively, for the azithromycin group and 92.3% (36/39), 100% (30/30), and 90.9% (10/11), respectively, for the levofloxacin group. Conclusions Single-dose azithromycin microspheres provided clinical and bacteriologic efficacy and safety comparable to 10 days of levofloxacin. Significance A novel microsphere formulation of azithromycin given as a single dose was safe and effective for the treatment of ABS.


Health and Quality of Life Outcomes | 2013

Responsiveness of the MOS-HIV and EQ-5D in HIV-infected adults receiving antiretroviral therapies

Albert W. Wu; Kristin A Hanson; Gale Harding; Seema Haider; Margaret Tawadrous; Alexandra Khachatryan; Chris L. Pashos; Kit N. Simpson

BackgroundSelection of an appropriate patient-reported outcome (PRO) instrument for a clinical trial requires knowledge of the instrument’s responsiveness to detecting treatment effects. The purpose of this study was to examine the responsiveness of two health-related quality of life (HRQL) instruments used in clinical trials involving HIV-infected adults: the HIV-targeted Medical Outcomes Study HIV Health Survey (MOS-HIV), and a generic measure, the EuroQol-5D (EQ-5D).MethodsA systematic review identified clinical trials using the MOS-HIV or EQ-5D to assess outcomes for HIV-infected adults. Data abstracted from each study included study type, treatment regimen(s), PRO results, and effect size (either reported or calculated). Effect size was calculated as the difference between baseline and follow-up mean scores divided by the baseline standard deviation. Magnitude was categorized as small (d=0.20), medium (d=0.50), and large (d=0.80).ResultsBetween 2005 and 2010, the MOS-HIV was administered in 12 trials. Significant differences were observed between groups and over time in physical health summary (PHS) and mental health summary (MHS) scores (P<0.05) in subjects switching therapy after experiencing Grade-2 adverse events. Effect sizes were medium (0.55 and 0.49 for PHS and MHS, respectively) among treatment-naïve adults beginning therapy (two studies), but negligible among treatment-experienced adults (0.04 and 0.13 for PHS and MHS, respectively; three studies). The EQ-5D was used in five trials between 2001 and 2010. It was responsive to occurrences of adverse events and opportunistic infections, with small-to-medium effect sizes (range 0.30–0.50) in each of its five dimensions.ConclusionsA systematic review of PRO study results showed both the MOS-HIV and EQ-5D were responsive to changes between groups and/or over time in treatment-naïve HIV-infected patients. These instruments may be used either individually or together in clinical trials to measure changes in HRQL.


Health and Quality of Life Outcomes | 2013

Patient reported outcome instruments used in clinical trials of HIV-infected adults on NNRTI-based therapy: a 10-year review

Kit N. Simpson; Kristin A Hanson; Gale Harding; Seema Haider; Margaret Tawadrous; Alexandra Khachatryan; Chris L. Pashos; Albert W. Wu

BackgroundPatient-reported outcomes (PROs) may provide valuable information to clinicians and patients when choosing initial antiretroviral therapy.ObjectiveTo identify and classify PRO instruments used to measure treatment effects in clinical trials evaluating NNRTIs.MethodsWe conducted a structured literature review using PubMed to identify NNRTI trials published from March 2003 to February 2013. Studies identified--based on disease, instrument, PRO, and NNRTI medication terms were reviewed--to identify PRO instruments. Domains measured within each instrument were recorded to understand key areas of interest in NNRTIs.ResultsOf 189 articles reviewed, 27 validated instruments were administered in 26 unique trials, with a mean of 1.9 instruments (median: 1; range: 1–7) per trial. The Medical Outcomes Study HIV Health Survey (MOS-HIV) was the most commonly used instrument (n = 8 trials). Seventeen trials (65%) included at least one multidimensional health-related quality of life (HRQL) instrument (HIV-targeted, n = 11; general, n = 8). Other validated instruments measured sleep (n = 5), depression (n = 5), anxiety (n = 4), psychiatric symptoms (n = 2), beliefs about HIV medications (n = 2), HIV symptoms (n = 1), and stress (n = 1).ConclusionsAlthough review of recent NNRTI trials suggests a lack of consensus on the optimal PRO instruments, a typical battery is comprised of a multidimensional HRQL measure coupled with one or more symptom measures. Further work is needed to clarify advantages and disadvantages of using specific PRO instruments to measure relevant constructs and to identify the most useful batteries of instruments for NNRTI trials.


Drug and Alcohol Dependence | 2012

Effect of lersivirine co-administration on pharmacokinetics of methadone in healthy volunteers

Manoli Vourvahis; Rong Wang; Daniel Mark Gruener; R. Douglas Bruce; Seema Haider; Margaret Tawadrous

BACKGROUND Lersivirine is a next-generation non-nucleoside reverse transcriptase inhibitor under development for the treatment of HIV-1 infection. HIV-1-infected patients receiving methadone may have a limited choice of antiretroviral agents due to drug-drug interactions. As methadone is metabolized by CYP3A4 and lersivirine is a weak CYP3A4 inducer, it is possible that lersivirine may decrease methadone concentrations. This study evaluated the effect of lersivirine on the pharmacokinetics (PK) of R- and S-methadone enantiomers. METHODS An open-label, single-sequence study was performed in 13 HIV-negative volunteers receiving stable methadone maintenance therapy (MMT) (50-150 mg QD) for ≥3 months. Healthy volunteers received their methadone to steady-state on day 1 and lersivirine (1000 mg QD) plus their same methadone dose on Days 2-11. Assessments included PK, safety, short opiate withdrawal scale (SOWS), desires for drugs questionnaire (DDQ) and pupillary diameter measurements (PDMs). RESULTS Following administration of methadone alone or in combination with lersivirine, R- and S-methadone concentrations did not appear different (ratios of adjusted geometric means for PK parameters: 95-104%). Following co-administration of lersivirine and methadone, adverse events (AEs) were generally mild to moderate in severity. One patient discontinued due to nausea. An examination of objective (vital signs, AEs, PDM), subjective (SOWS and DDQ scores) and PK data suggested that subjects did not experience opioid withdrawal during the study. CONCLUSIONS Co-administration of lersivirine (1000 mg QD) with methadone did not result in clinically relevant changes in R-/S-methadone concentrations or opioid withdrawal symptoms. No methadone dose adjustment is required when lersivirine is administered alongside MMT.


Clinical Therapeutics | 2010

Safety and tolerability of lersivirine, a nonnucleoside reverse transcriptase inhibitor, during a 28-day, randomized, placebo-controlled, Phase I clinical study in healthy male volunteers.

John Davis; Frances Hackman; Marie-Noella Ndongo; HengWee Choo; Drew Lewis; Margaret Tawadrous; James Goodrich; Grant Langdon

BACKGROUND Lersivirine is a nonnucleoside reverse transcriptase inhibitor undergoing clinical development for the treatment of HIV-1. OBJECTIVE 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. METHODS 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. RESULTS 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. CONCLUSION Lersivirine appeared to be well tolerated after 28 days of continuous dosing in this small, selected group of young, healthy male volunteers.


Hiv Medicine | 2014

Costs of adverse events among patients with HIV infection treated with nonnucleoside reverse transcriptase inhibitors.

Kit N. Simpson; Chen Sy; Albert W. Wu; Boulanger L; Richard Chambers; Katherine Nedrow; Margaret Tawadrous; Pashos Cl; Seema Haider

The aim of the study was to assess the incidence and costs of adverse events (AEs) among patients with HIV infection treated with nonnucleoside reverse transcriptase inhibitors (NNRTIs) from the health care system perspective.


Antimicrobial Agents and Chemotherapy | 2012

No Effect of a Single Supratherapeutic Dose of Lersivirine, a Next-Generation Nonnucleoside Reverse Transcriptase Inhibitor, on Corrected QT Interval in Healthy Subjects

Manoli Vourvahis; Rong Wang; Marie-Noella Ndongo; Melissa O'Gorman; Margaret Tawadrous

ABSTRACT The objective of this study was to investigate the effect of a supratherapeutic dose of lersivirine (LRV) on corrected QT (QTc) interval using Fridericias equation (QTcF) in healthy subjects. In this randomized, single-dose, placebo- and active-controlled 3-way crossover study, healthy adult males (n = 48) were randomized to receive LRV (2,400 mg), moxifloxacin (400 mg), or placebo for each treatment period. Triplicate 12-lead electrocardiogram measurements were performed, PK samples were collected, and vital signs were measured. Adverse event monitoring and safety laboratory testing were performed. All subjects were white (mean age, 39 years; body mass index [BMI], 25.6 kg/m2) and completed the study. Following LRV administration, the upper bound of the 90% confidence interval (CI) for time-matched adjusted mean differences to placebo QTcF at each time point postdose was below the regulatory threshold of 10 ms, satisfying the criteria for a negative thorough QT/QTc study. The highest upper bound of QTcF 90% CI occurred at 6 h for LRV (3.32 ms; 90% CI, 1.47 to 5.17 ms). The study was deemed adequately sensitive as the lower bound of the 90% CI for the adjusted mean QTcF differences between moxifloxacin and placebo at the moxifloxacin historical Tmax of 3 h was >5 ms (15.29 ms; 90% CI, 13.44 to 17.14 ms). There was no statistically significant relationship between LRV exposure and placebo-adjusted change from baseline QTcF or clinically significant changes in QRS complex, pulse rate (PR) interval, heart rate, or blood pressure. LRV (2,400 mg) did not prolong the QTcF interval, and no clinically relevant electrocardiogram or vital sign changes were observed in healthy subjects.


Antimicrobial Agents and Chemotherapy | 2012

Effect of Rifampin and Rifabutin on the Pharmacokinetics of Lersivirine and Effect of Lersivirine on the Pharmacokinetics of Rifabutin and 25-O-Desacetyl-Rifabutin in Healthy Subjects

Manoli Vourvahis; John Davis; Rong Wang; Gary Layton; Heng Wee Choo; Chew Lan Chong; Margaret Tawadrous

ABSTRACT Lersivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) with a unique resistance profile exhibiting potent antiviral activity against wild-type HIV and several clinically relevant NNRTI-resistant strains. Lersivirine, a weak inducer of the cytochrome P450 (CYP) enzyme CYP3A4, is metabolized by CYP3A4 and UDP glucuronosyltransferase 2B7 (UGT2B7). Two open, randomized, two-way (study 1; study A5271008) or three-way (study 2; study A5271043) crossover phase I studies were carried out under steady-state conditions in healthy subjects. Study 1 (n = 17) investigated the effect of oral rifampin on the pharmacokinetics (PKs) of lersivirine. Study 2 (n = 18) investigated the effect of oral rifabutin on the PKs of lersivirine and the effect of lersivirine on the PKs of rifabutin and its active metabolite, 25-O-desacetyl-rifabutin. Coadministration with rifampin decreased the profile of the lersivirine area under the plasma concentration-time curve from time zero to 24 h postdose (AUC24), maximum plasma concentration (Cmax), and plasma concentration observed at 24 h postdose (C24) by 85% (90% confidence interval [CI], 83, 87), 83% (90% CI, 79, 85), and 92% (90% CI, 89, 94), respectively, versus the values for lersivirine alone. Coadministration with rifabutin decreased the lersivirine AUC24, Cmax, and C24 by 34% (90% CI, 29, 39), 25% (90% CI, 16, 33), and 58% (90% CI, 52, 64), respectively, compared with the values for lersivirine alone. Neither the rifabutin concentration profile nor overall exposure was affected following coadministration with lersivirine. Lersivirine and rifabutin reduced the 25-O-desacetyl-rifabutin AUC24 by 27% (90% CI, 21, 32) and Cmax by 27% (90% CI, 19, 34). Lersivirine should not be coadministered with rifampin, which is a potent inducer of CYP3A4, UGT2B7, and P-glycoprotein activity and thus substantially lowers lersivirine exposure. No dose adjustment of rifabutin is necessary in the presence of lersivirine; an upward dose adjustment of lersivirine may be warranted when it is coadministered with rifabutin.

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Kit N. Simpson

Medical University of South Carolina

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Albert W. Wu

Johns Hopkins University

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