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Dive into the research topics where James Witek is active.

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Featured researches published by James Witek.


Hepatology | 2016

Simeprevir plus sofosbuvir in patients with chronic hepatitis C virus genotype 1 infection and cirrhosis: A phase 3 study (OPTIMIST-2).

Eric Lawitz; Gary Matusow; Edwin DeJesus; Eric M. Yoshida; Franco Felizarta; Reem Ghalib; Eliot Godofsky; Robert Herring; Gary Poleynard; Aasim M. Sheikh; Hillel Tobias; Marcelo Kugelmas; Ronald Kalmeijer; M Peeters; Oliver Lenz; Bart Fevery; Guy De La Rosa; Jane Scott; Rekha Sinha; James Witek

Hepatitis C virus (HCV)–infected patients with cirrhosis are historically a difficult‐to‐treat population and are at risk of hepatic decompensation. In the phase 2 COSMOS study that evaluated simeprevir (HCV NS3/4A protease inhibitor) + sofosbuvir (HCV nucleotide analogue NS5B polymerase inhibitor) ± ribavirin for 12 or 24 weeks in HCV genotype (GT)1–infected patients, high rates of sustained virologic response 12 weeks after planned end of treatment (SVR12) were achieved, including in patients with cirrhosis (METAVIR score F4). This phase 3, open‐label, single‐arm study (OPTIMIST‐2 [NCT02114151]) evaluated the efficacy and safety of 12 weeks of simeprevir + sofosbuvir in HCV GT1–infected treatment‐naive or treatment‐experienced patients with cirrhosis. Patients (aged 18‐70 years) with chronic HCV GT1 infection and documented presence of cirrhosis received oral simeprevir 150 mg once daily + sofosbuvir 400 mg once daily for 12 weeks. The primary efficacy endpoint of the study was the proportion of patients achieving SVR12 versus a composite historical control (SVR12 rate of 70%). Safety and patient‐reported outcomes were assessed. Overall, 103 patients received treatment. SVR12 with simeprevir + sofosbuvir (83%, 95% confidence interval 76%‐91%) met the primary objective of superiority versus the historical control (70%). SVR12 rates for treatment‐naive and treatment‐experienced patients were 88% (44/50) and 79% (42/53), respectively. Adverse events occurred in 72 (70%) patients, with most (64%) being grade 1 or 2. Serious adverse events (none considered related to study treatment) occurred in five (5%) patients, and three (3%) patients discontinued all study treatment due to adverse events. Patient‐reported outcomes improved from baseline to follow‐up week 12. Conclusion: Simeprevir + sofosbuvir for 12 weeks achieved superiority in SVR12 rates versus the historical control in treatment‐naive and treatment‐experienced HCV GT1‐infected patients with cirrhosis and was generally safe and well tolerated. (Hepatology 2016;64:360‐369)


Hepatology | 2016

Simeprevir plus sofosbuvir (12 and 8 weeks) in hepatitis C virus genotype 1-infected patients without cirrhosis: OPTIMIST-1, a phase 3, randomized study.

Paul Y. Kwo; Norman Gitlin; Ronald Nahass; David Bernstein; Kyle P. Etzkorn; Sergio Rojter; Eugene R. Schiff; Mitchell Davis; Peter Ruane; Ziad Younes; Ronald Kalmeijer; Rekha Sinha; M Peeters; Oliver Lenz; Bart Fevery; Guy De La Rosa; Jane Scott; James Witek

Effective antiviral therapy is essential for achieving sustained virological response (SVR) in hepatitis C virus (HCV)‐infected patients. The phase 2 COSMOS study reported high SVR rates in treatment‐naive and prior null‐responder HCV genotype (GT) 1‐infected patients receiving simeprevir+sofosbuvir±ribavirin for 12 or 24 weeks. OPTIMIST‐1 (NCT02114177) was a multicenter, randomized, open‐label study assessing the efficacy and safety of 12 and 8 weeks of simeprevir+sofosbuvir in HCV GT1‐infected treatment‐naive and treatment‐experienced patients without cirrhosis. Patients were randomly assigned (1:1; stratified by HCV GT/subtype and presence or absence of NS3 Q80K polymorphism [GT1b, GT1a with Q80K, GT1a without Q80K]), prior HCV treatment history, and IL28B GT [CC, non‐CC]) to simeprevir 150 mg once daily+sofosbuvir 400 mg once daily for 12 or 8 weeks. The primary efficacy endpoint was SVR rate 12 weeks after end of treatment (SVR12). Superiority in SVR12 was assessed for simeprevir+sofosbuvir at 12 and 8 weeks versus a composite historical control SVR rate. Enrolled were 310 patients, who were randomized and received treatment (n = 155 in each arm). SVR12 with simeprevir+sofosbuvir for 12 weeks (97% [150/155; 95% confidence interval 94%‐100%]) was superior to the historical control (87%). SVR12 with simeprevir+sofosbuvir for 8 weeks (83% [128/155; 95% confidence interval 76‐89%]) was not superior to the historical control (83%). The most frequent adverse events were nausea, headache, and fatigue (12‐week arm: 15% [23/155], 14% [22/155], and 12% [19/155]; 8‐week arm: 9% [14/155], 17% [26/155], and 15% [23/155], respectively). No patients discontinued treatment due to an adverse event. One (1%, 12‐week arm) and three (2%, 8‐week arm) patients experienced a serious adverse event (all unrelated to study treatment). Conclusion: Simeprevir+sofosbuvir for 12 weeks is highly effective in the treatment of HCV GT1‐infected patients without cirrhosis, including those with Q80K. (Hepatology 2016;64:370‐380)


Antiviral Therapy | 2010

Efficacy and safety of etravirine at week 96 in treatment-experienced HIV type-1-infected patients in the DUET-1 and DUET-2 trials.

Christine Katlama; Bonaventura Clotet; Anthony Mills; Benoit Trottier; Jean-Michel Molina; Beatriz Grinsztejn; William Towner; Richard Haubrich; Steven Nijs; Johan Vingerhoets; Brian Woodfall; James Witek

BACKGROUND Durable efficacy and long-term safety of antiretroviral therapy are important goals in the management of treatment-experienced patients. The 96-week efficacy and safety of the non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine were evaluated in the Phase III DUET trials. METHODS HIV type-1-infected treatment-experienced adults with viral loads >5,000 copies/ml and NNRTI and protease inhibitor resistance were randomized to receive etravirine 200 mg or placebo, each twice daily and in combination with a background regimen of darunavir/ritonavir twice daily, nucleoside/nucleotide reverse transcriptase inhibitors and optional enfuvirtide. The primary end point was the proportion of patients with viral load <50 copies/ml (intent-to-treat analysis, time-to-loss of virological response algorithm) at week 24. Results from both trials were combined in the pre-specified pooled 96-week analysis. RESULTS In total, 599 patients received etravirine and 604 received placebo. At week 96, 57% of patients in the etravirine group versus 36% in the placebo group had a viral load <50 copies/ml (P<0.0001); 91% and 88% of patients, respectively, had maintained this response from week 48. Mean increases in CD4(+) T-cell count from baseline at week 96 were 128 cells/mm(3) with etravirine versus 86 cells/mm(3) with placebo (P<0.0001). With the exception of rash, which was reported more frequently with etravirine than placebo (21% versus 12%, respectively; P<0.0001), the safety and tolerability profile of etravirine was similar to placebo over the treatment period. CONCLUSIONS Etravirine, in combination with an antiretroviral background regimen, provided durable virological and immunological responses with no new safety concerns in treatment-experienced patients over 96 weeks in the DUET trials.


Antiviral Research | 2015

Prevalence of the hepatitis C virus NS3 polymorphism Q80K in genotype 1 patients in the European region

Christoph Sarrazin; Erkki Lathouwers; M Peeters; Bjorn Daems; Annemie Buelens; James Witek; Yves Wyckmans; Bart Fevery; Thierry Verbinnen; Anne Ghys; Michael Schlag; Alessandra Baldini; Sandra De Meyer; Oliver Lenz

Hepatitis C virus (HCV) NS3 polymorphism Q80K is mainly found in patients with HCV genotype (G) 1a, and has been associated with a reduced treatment response to simeprevir with pegylated interferon (P) and ribavirin (R). Prevalence of Q80K among G1 patients may vary geographically. Q80K prevalence in the North-American G1 population in a recent study was 34%. We conducted a post hoc meta-analysis of Q80K polymorphism prevalence among HCV G1-infected patients enrolled in simeprevir and telaprevir Phase II/III studies. Baseline HCV NS3/4A protease sequences were analysed by population sequencing to determine Q80K prevalence. Overall, of 3349 patients from 25 countries in the European region analysed, 35.8%, 63.8% and 0.3% of patients had G1a, G1b and other/unknown HCV G1 subtypes, respectively. Q80K was detected at baseline in 7.5% of HCV G1 patients overall. Examination by subtype showed that 19.8%, 0.5% and 18.2% of patients with G1a, G1b and other/unknown HCV G1 subtypes had the Q80K polymorphism, respectively. Among countries in the European region with sequencing data available for either ⩾20 patients with G1a and/or ⩾40 G1 patients overall, the Q80K prevalence in G1 ranged from 0% in Bulgaria to 18.2% in the UK. Q80K prevalence also varied within G1a across different countries. HCV subtype 1a was correctly determined in 99% of patients by the LiPA v2 assay. A low overall prevalence of Q80K was observed in HCV G1-infected patients in the European region, compared with North America. However, the prevalence varied by country, due to differing ratios of G1a/G1b and differing Q80K prevalence within the G1a populations.


Gastroenterology | 2014

Telaprevir twice daily is noninferior to telaprevir every 8 hours for patients with chronic hepatitis C.

Maria Buti; Kosh Agarwal; Yves Horsmans; William Sievert; E. Janczewska; Stefan Zeuzem; Lisa M. Nyberg; Robert S. Brown; Christophe Hézode; Mario Rizzetto; Raymundo Paraná; Sandra De Meyer; Ralph J De Masi; D. Luo; Kirk Bertelsen; James Witek

BACKGROUND & AIMS We performed an open-label, multicenter, phase 3 study of the safety and efficacy of twice-daily telaprevir in treatment-naive patients with chronic hepatitis C virus (HCV) genotype 1 infection, including those with cirrhosis. METHODS Patients were randomly assigned to groups treated with telaprevir 1125 mg twice daily or 750 mg every 8 hours plus peginterferon alfa-2a and ribavirin for 12 weeks; patients were then treated with peginterferon alfa-2a and ribavirin alone for 12 weeks if their level of HCV RNA at week 4 was <25 IU/mL or for 36 weeks if their level was higher. The primary objective was to demonstrate noninferiority of telaprevir twice daily versus every 8 hours in producing a sustained virological response 12 weeks after the end of therapy (SVR12) (based on a -11% lower limit of the 95% lower confidence interval for the difference between groups). RESULTS At baseline, of 740 patients, 85% had levels of HCV RNA ≥800,000 IU/mL, 28% had fibrosis (F3-F4), 14% had cirrhosis (F4), 57% were infected with HCV genotype 1a, and 71% had the non-CC IL28B genotype. Of patients who were treated with telaprevir twice daily, 74.3% achieved SVR12 compared with 72.8% of patients who were treated with telaprevir every 8 hours (difference in response, 1.5%; 95% confidence interval, -4.9% to 12.0%), so telaprevir twice daily is noninferior to telaprevir every 8 hours. All subgroups of patients who were treated with telaprevir twice daily versus those who were treated every 8 hours had similar rates of SVR12. The most frequent adverse events (AEs) in the telaprevir phase were fatigue (47%), pruritus (43%), anemia (42%), nausea (37%), rash (35%), and headache (26%); serious AEs were reported in 9% of patients. Rates of AEs and serious AEs were similar or slightly higher among patients treated with telaprevir every 8 hours. CONCLUSIONS Based on a phase 3 trial, telaprevir twice daily is noninferior to every 8 hours in producing SVR12, with similar levels of safety and tolerability. These results support use of telaprevir twice daily in patients with chronic HCV genotype 1 infection, including those with cirrhosis. ClinicalTrials.gov, Number: NCT01241760.


Antiviral Therapy | 2010

Pharmacokinetics of once-daily etravirine without and with once-daily darunavir/ritonavir in antiretroviral-naive HIV type-1-infected adults.

Edwin DeJesus; Jacob Lalezari; Olayemi Osiyemi; Peter Ruane; Robert Ryan; Thomas N. Kakuda; James Witek

BACKGROUND A pharmacokinetic trial was conducted to evaluate the potential for once-daily etravirine in antiretroviral regimens without and with darunavir/ritonavir. METHODS 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. RESULTS 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. CONCLUSIONS 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.).


Antimicrobial Agents and Chemotherapy | 2013

Pharmacokinetic Interaction between Telaprevir and Methadone

Rolf van Heeswijk; Peter Verboven; Ann Vandevoorde; Petra Vinck; Jan Snoeys; Griet Boogaerts; Els De Paepe; Rodica Van Solingen-Ristea; James Witek; Varun Garg

ABSTRACT Hepatitis C virus (HCV) antibody is present in most patients enrolled in methadone maintenance programs. Therefore, interactions between the HCV protease inhibitor telaprevir and methadone were investigated. The pharmacokinetics of R- and S-methadone were measured after administration of methadone alone and after 7 days of telaprevir (750 mg every 8 h [q8h]) coadministration in HCV-negative subjects on stable, individualized methadone therapy. Unbound R-methadone was measured in predose plasma samples before and during telaprevir coadministration. Safety and symptoms of opioid withdrawal were evaluated throughout the study. In total, 18 subjects were enrolled; 2 discontinued prior to receiving telaprevir. The minimum plasma concentration in the dosing interval (Cmin), the maximum plasma concentration (Cmax), and the area under the plasma concentration-time curve from h 0 (time of administration) to 24 h postdose (AUC0–24) for R-methadone were reduced by 31%, 29%, and 29%, respectively, in the presence of telaprevir. The AUC0–24 ratio of S-methadone/R-methadone was not altered. The median unbound percentage of R-methadone increased by 26% in the presence of telaprevir. The R-methadone median (absolute) unbound Cmin values in the absence (10.63 ng/ml) and presence (10.45 ng/ml) of telaprevir were similar. There were no symptoms of opioid withdrawal and no discontinuations due to adverse events. In summary, exposure to total R-methadone was reduced by approximately 30% in the presence of telaprevir, while the exposure to unbound R-methadone was unchanged. No symptoms of opioid withdrawal were observed. These results suggest that dose adjustment of methadone is not required when initiating telaprevir treatment. (This study has been registered at ClinicalTrials.gov under registration no. NCT00933283.)


Journal of Acquired Immune Deficiency Syndromes | 2010

Efficacy, safety, and tolerability of etravirine with and without darunavir/ritonavir or raltegravir in treatment-experienced patients: analysis of the etravirine early access program in the United States.

William Towner; Jacob Lalezari; Michael Sension; Michael Wohlfeiler; Joseph Gathe; Jonathan S Appelbaum; Paul Bellman; Michael S. Gottlieb; Robert Ryan; Steven Nijs; Annemie Hoogstoel; Rodica Van Solingen-Ristea; James Witek

Background:Etravirine, a nonnucleoside reverse transcriptase inhibitor, was provided through an international early access program (EAP) prior to regulatory approval. Methods:The Phase III, nonrandomized, open-label EAP investigated etravirine 200 mg twice daily plus a background regimen (BR) in patients who had failed multiple antiretroviral regimens. Efficacy and safety are reported for HIV-infected adults from the United States through week 48, including subgroups receiving etravirine ± darunavir/ritonavir and/or raltegravir. Results:The intent-to-treat population included 2578 patients; 62.4% and 56.7% of patients received darunavir/ritonavir and raltegravir, respectively, in their BR. At week 48, 62.3% of patients achieved viral loads <75 copies per milliliter; responses across subgroups were similar. Median CD4+ count increase from baseline was >100 cells per cubic millimeter. No unexpected safety concerns emerged; serious AEs and deaths due to AEs, considered possibly related to etravirine, occurred in 2.0% and 0.3% of patients, respectively. Discontinuations due to AEs were low overall (4.4%) and comparable across subgroups. Conclusions:Etravirine combined with a BR, often including other new antiretrovirals, such as darunavir/ritonavir and/or raltegravir, provided an effective treatment option in treatment-experienced patients with HIV-1.


The Journal of Clinical Pharmacology | 2014

Pharmacokinetic interaction between etravirine or rilpivirine and telaprevir in healthy volunteers: A randomized, two‐way crossover trial

Thomas N. Kakuda; Lorant Leopold; Steven Nijs; Ann Vandevoorde; Herta Crauwels; Kirk Bertelsen; Marita Stevens; James Witek; Yvon van Delft; Frank Tomaka; Richard M. W. Hoetelmans

Coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) may require treatment with an HIV non‐nucleoside reverse transcriptase inhibitor (NNRTI), for example, rilpivirine or etravirine, and an HCV direct‐acting antiviral drug such as telaprevir. In a two‐panel, two‐way, crossover study, healthy volunteers were randomized to receive etravirine 200 mg twice daily ± telaprevir 750 mg every 8 hours or rilpivirine 25 mg once daily ± telaprevir 750 mg every 8 hours. Pharmacokinetic assessments were conducted for each drug at steady‐state when given alone and when coadministered; statistical analyses were least‐square means with 90% confidence intervals. Telaprevir minimum plasma concentration (Cmin), maximum plasma concentration (Cmax), and area under the concentration–time curve (AUC) decreased 25%, 10%, and 16%, respectively, when coadministered with etravirine and 11%, 3%, and 5%, respectively, when coadministered with rilpivirine. Telaprevir did not affect etravirine pharmacokinetics, but increased rilpivirine Cmin, Cmax, and AUC by 93%, 49%, and 78%, respectively. Both combinations were generally well tolerated. The small decrease in telaprevir exposure when coadministered with etravirine is unlikely to be clinically relevant. The interaction between telaprevir and rilpivirine is not likely to be clinically relevant under most circumstances. No dose adjustments are deemed necessary when they are coadministered.


Hepatology | 2013

Homeostasis model assessment of insulin resistance does not seem to predict response to telaprevir in chronic hepatitis C in the REALIZE trial.

Zobair M. Younossi; Francesco Negro; Lawrence Serfaty; Stanislas Pol; M. Diago; Stefan Zeuzem; Pietro Andreone; Eric Lawitz; Stuart K. Roberts; Roberto Focaccia; Graham R. Foster; Andrzej Horban; Isabelle Lonjon-Domanec; Bruce Coate; Ralph DeMasi; G. Picchio; James Witek

Baseline homeostasis model assessment‐estimated insulin resistance (HOMA‐IR), a marker for insulin resistance, has been associated with poor virologic response to peginterferon alpha/ribavirin (PR) in chronic hepatitis C. We evaluated the association between baseline HOMA‐IR and pretreatment factors on sustained virologic response (SVR) to telaprevir (TVR) in genotype 1 patients with hepatitis C and prior peginterferon/ribavirin (PR) treatment failure. Patients were randomized to 12 weeks of TVR (750 mg q8h) plus peginterferon (180 μg/week) and ribavirin (1,000‐1,200 mg/day) (with or without a 4‐week lead‐in) followed by PR, or PR alone (PR48), for 48 weeks. Univariate and multiple logistic regression analyses explored the prognostic significance of baseline HOMA‐IR alone and adjusted for other pretreatment factors and SVR. The TVR arms were pooled for the purposes of this analysis. In all, 662 patients were randomized; 578 had baseline HOMA‐IR and other prognostic data and were included in this analysis. Median baseline HOMA‐IR was 2.6 (interquartile range [IQR] 1.7‐4.3); 207 (36%), 206 (36%), and 165 (29%) patients had baseline HOMA‐IR <2, 2 to <4, and ≥4, respectively. Male gender, higher body mass index, triglycerides, gamma‐glutamyl transpeptidase, maximum alanine aminotransferase/aspartate aminotransferase, and fibrosis stage were associated with higher baseline HOMA‐IR. Baseline HOMA‐IR was associated with SVR in univariate analysis, but not after adjustment for other baseline prognostic factors (TVR: OR = 0.95, 95% confidence interval [CI]: 0.71,1.29; PR48: 0.60; 95% CI: 0.25,1.43). Conclusion: In patients with prior PR treatment failure, baseline HOMA‐IR correlated with SVR in univariate but not multivariate analyses, suggesting other factors have a more direct causal relationship with virologic response to TVR‐based therapy than HOMA‐IR. (Hepatology 2013; 58:1897–1906)

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Stefan Zeuzem

Goethe University Frankfurt

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D. Luo

Janssen Pharmaceutica

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Kosh Agarwal

University of Cambridge

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Maria Buti

Instituto de Salud Carlos III

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M Peeters

Janssen Pharmaceutica

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