23 results on '"Faucette S"'
Search Results
2. DIETHYLDITHIOCARBAMATE (DDC) INHIBITION OF CYP2B6 CATALYTIC ACTIVITY.
- Author
-
Faucette, S., Shifflett, S., LeCluyse, E., Hawke, R., and Lindley, C.
- Published
- 2000
3. ASSESSMENT OF CYP3A4(3A4) CONTRIBUTION TO BUPROPION (B) HYDROXYLATION IN HUMAN LIVER MICROSOMES (HLMs).
- Author
-
Faucette, S., Hawke, R., Shifflett, S., LeCluyse, E., and Lindley, C.
- Published
- 2000
4. TAK-659, AN INVESTIGATIONAL REVERSIBLE DUAL SYK/FLT-3 INHIBITOR, IN PATIENTS WITH LYMPHOMA: UPDATED RESULTS FROM DOSE-ESCALATION AND EXPANSION COHORTS OF a PHASE 1 STUDY
- Author
-
Kaplan, J., primary, Gordon, L., additional, Infante, J., additional, Popat, R., additional, Rambaldi, A., additional, Madan, S., additional, Patel, M.R., additional, Gritti, G., additional, El-Sharkawi, D., additional, Chau, I., additional, Radford, J., additional, Perez De Oteyza, J., additional, Zinzani, P., additional, Iyer, S., additional, Faucette, S., additional, Sheldon-Waniga, E., additional, Stumpo, K., additional, Shou, Y., additional, Carpio, C., additional, and Bosch, F., additional
- Published
- 2017
- Full Text
- View/download PDF
5. Relative Activation of Human Pregnane X Receptor versus Constitutive Androstane Receptor Defines Distinct Classes of CYP2B6 and CYP3A4 Inducers
- Author
-
Wang, H., Moore, R., Negishi, M., Omiecinski, C. J., Sueyoshi, T., Zhang, T.-C., LeCluyse, E. L., and Faucette, S. R.
- Abstract
Both the human pregnane X receptor (hPXR) and constitutive androstane receptor (hCAR) are capable of regulating CYP3A4 and CYP2B6 gene expression. However, the majority of currently identified CYP3A4 and CYP2B6 inducers are confirmed activators of hPXR but not hCAR. To compare these receptors with respect to their chemical selectivities, 16 drugs known to induce CYP3A4 and/or CYP2B expression were evaluated for relative activation of hPXR versus hCAR. Because of the high basal but low chemical-induced activation of hCAR in immortalized cells, alternative methods were used to evaluate hCAR activation potential. Thirteen of the 16 compounds were classified as moderate to strong hPXR activators. In contrast, carbamazepine (CMZ), efavirenz (EFV), and nevirapine (NVP) were classified as negligible or weak hPXR activators at concentrations associated with efficacious CYP2B6 reporter or endogenous gene induction in primary human hepatocytes, suggesting potential activation of hCAR. Subsequent experiments demonstrated that these three drugs efficiently induced nuclear accumulation of in vivo-transfected enhanced yellow fluorescent protein-hCAR and significantly increased expression of a CYP2B6 reporter gene when hCAR was expressed in CAR−/− mice. In addition, using a recently identified, chemically responsive splice variant of hCAR (hCAR3), the hCAR activation profiles of the 16 compounds were evaluated. By combining results from the hPXR- and hCAR3-based reporter gene assays, these inducers were classified as hPXR, hCAR, or hPXR/hCAR dual activators. Our results demonstrate that CMZ, EFV, and NVP induce CYP2B6 and CYP3A4 preferentially through hCAR and that hCAR3 represents a sensitive tool for in vitro prediction of chemical-mediated human CAR activation.
- Published
- 2006
- Full Text
- View/download PDF
6. First-in-human, multicenter, dose-escalation, phase I study of the investigational drug TAK-733, an oral MEK inhibitor, in patients (pts) with advanced nonhematologic malignancies and melanoma.
- Author
-
Sosman, J. A., primary, Adjei, A. A., additional, LoRusso, P., additional, Michael, S. A., additional, Dy, G. K., additional, Bowditch, A., additional, Chmielowski, B., additional, Lee, S., additional, Walker, R. M., additional, Faucette, S., additional, Izmailova, E. S., additional, Bozon, V., additional, and Ribas, A., additional
- Published
- 2011
- Full Text
- View/download PDF
7. 399 Pharmacokinetics and Pharmacodynamics of TAK-733, an Investigational, Oral MEK Inhibitor, in Patients with Advanced Nonhematologic Malignancies
- Author
-
Zhou, X., Faucette, S., Kaun, S., Gangolli, E., Bozon, V., and Venkatakrishnan, K.
- Published
- 2012
- Full Text
- View/download PDF
8. Measured versus estimated glomerular filtration rate in the Calvert equation: influence on carboplatin dosing.
- Author
-
Donahue, Angela, McCune, Jeannine S., Faucette, Stephanie, Gillenwater, Heidi H., Kowalski, Richard J., Socinski, Mark A., Lindley, Celeste, Donahue, A, McCune, J S, Faucette, S, Gillenwater, H H, Kowalski, R J, Socinski, M A, and Lindley, C
- Subjects
GLOMERULAR filtration rate ,DRUG dosage ,KIDNEY function tests ,KIDNEY glomerulus ,BLOOD plasma ,LUNG cancer - Abstract
Purpose: Carboplatin is frequently dosed to achieve a desired area under the plasma concentration-time curve (AUC) by using the Calvert or Chatelut equations to estimate carboplatin clearance. Accurate determination of glomerular filtration rate (GFR) is necessary to correctly calculate carboplatin clearance using the Calvert equation. In clinical practice, the Cockcroft-Gault formula is frequently used to estimate GFR, but this practice has been reported to under- and overestimate carboplatin clearance. The purpose of this trial was to compare determinations of carboplatin clearance using the Chatelut equation and four separate GFR determinations, including
99m Tc-DTPA, the Cockcroft-Gault formula, a 24-h urine collection and a 2-h urine collection. Methods: Carboplatin clearance was estimated in 21 previously untreated extensive-stage small-cell lung cancer patients. GFR was determined using99m Tc-DTPA, the Cockcroft-Gault formula, 24-h urine collection and 2-h urine collection. Serum and urine creatinine concentrations were measured using enzymatic assays. The carboplatin clearance was then calculated by individually adding 25 to the four GFR determinations based on the Calvert equation, which states that carboplatin clearance equals GFR+25 (nonrenal clearance). The carboplatin clearance was also estimated using the Chatelut equation. The five determinations of carboplatin clearance were compared using Friedman's test and post-hoc Wilcoxon signed rank tests. Precision and bias for each carboplatin clearance determination were calculated assuming that99m Tc-DTPA provided the most accurate measure of GFR. Results: A statistically significant difference was found between the five methods of estimating carboplatin clearance (P<0.001). No difference was found between carboplatin clearance calculated using99m Tc-DTPA and the Chatelut equation, the Cockcroft-Gault formula or the 2-h urine collection. The Chatelut equation provided more precision and less bias than the 2-h urine collection (median precision 20% and 30%, median bias –1% and –18%, respectively). Conclusion: Compared to99m Tc-DTPA, the Chatelut equation more accurately estimates carboplatin clearance than the Cockcroft-Gault formula, the 2-h urine collection and the 24-h urine collection. The greater negative bias found for the latter three estimates of carboplatin clearance could result in underdosing of carboplatin. [ABSTRACT FROM AUTHOR]- Published
- 2001
- Full Text
- View/download PDF
9. Evaluation of the contribution of cytochrome P450 3A4 to human liver microsomal bupropion hydroxylation.
- Author
-
R, Faucette S, L, Hawke R, S, Shord S, L, Lecluyse E, and M, Lindley C
- Abstract
The purpose of this investigation was to evaluate the role of cytochrome P450 (CYP) 3A4 in human liver microsomal bupropion (BUP) hydroxylation. Across the BUP concentration range of 0.075 to 12 mM, cDNA-expressed CYP3A4 demonstrated BUP hydroxylase activity only when incubated with concentrations > or =4 mM. When assayed at 12 mM BUP, cDNA-expressed CYP3A4 catalyzed BUP hydroxylation at a 30-fold lower rate than cDNA-expressed CYP2B6 (0.2 versus 7 pmol/min/pmol of P450). Among a panel of 16 human liver microsomes (HLMs), BUP hydroxylase activity varied 80-fold when assayed at 500 microM and did not strongly correlate with testosterone 6beta-hydroxylase activity when assayed at 250 microM testosterone (r(2) = 0.39), nor with CYP3A4 protein expression. A selective CYP3A4 inhibitor, troleandomycin (TAO), did not significantly alter rates of BUP hydroxylation when assayed in a moderate activity HLM at 10 to 2000 microM BUP, as reflected by a similarity in the kinetic parameters of BUP hydroxylation in the absence or presence of TAO. In addition, the same range of TAO concentrations (0.025-100 microM) that inhibited testosterone 6beta-hydroxylation in a concentration-dependent manner (46-81%) in pooled HLMs produced negligible inhibition (7%) of BUP hydroxylation when assayed at 500 microM BUP. These results suggest that CYP3A4 does not significantly catalyze BUP hydroxylation. Furthermore, these results complement recent data supporting selectivity of BUP hydroxylation for CYP2B6 at 500 microM BUP.
- Published
- 2001
10. Validation of bupropion hydroxylation as a selective marker of human cytochrome P450 2B6 catalytic activity.
- Author
-
R, Faucette S, L, Hawke R, L, Lecluyse E, S, Shord S, B, Yan, M, Laethem R, and M, Lindley C
- Abstract
The purpose of this study was to establish bupropion (BUP) hydroxylation as a selective in vitro marker of cytochrome P450 (CYP) 2B6 catalytic activity. Among a panel of 16 human liver microsomes (HLMs), BUP hydroxylase activity varied 80-fold when assayed at 500 microM substrate and significantly correlated with CYP2B6 blotting density (r(2) = 0.99) and S-mephenytoin N-demethylase activity (r(2) = 0.98). Kinetic analysis of BUP hydroxylation was performed in a subset of seven HLMs representative of the 80-fold range in activity. Sigmoidal kinetics suggestive of allosteric activation was observed in five HLMs exhibiting low or high activity; the mean apparent K(m) for BUP hydroxylation in these HLMs (130 microM) was similar to the K(m) for cDNA-expressed CYP2B6 (156 microM). Nonsaturable, biphasic kinetics was observed in two HLMs exhibiting low activity. Among a panel of cDNA-expressed P450 isoforms, CYP2B6 and CYP2E1 demonstrated the highest rates of BUP hydroxylation at 12 mM BUP (7.0 and 2.4 pmol/min/pmol of P450, respectively). The relative contributions of CYP2B6 and CYP2E1 to BUP hydroxylation were estimated by using immunoinhibitory monoclonal antibodies (MAB) to these enzymes. MAB-2B6 produced 88% maximum inhibition of BUP hydroxylation when assayed at 12 mM BUP in a high activity HLM, whereas MAB-2E1 produced 81% maximum inhibition in a low activity HLM. However, negligible inhibition by MAB-2E1 was observed when low and high activity HLMs were assayed at 500 microM BUP. These results demonstrate selectivity of BUP hydroxylation for CYP2B6 at 500 microM BUP, thereby validating its use as a diagnostic in vitro marker of CYP2B6 catalytic activity.
- Published
- 2000
11. Phase I trial of topotecan (T) carboplatin (C) and etoposide (E) for extensive stage small cell lung cancer (ES-SCLC)
- Author
-
Gillenwater, H. H., McCune, J. S., Donahue, A. E., Faucette, S. R., Shifflett, S., Lindley, C., and Socinski, M. A.
- Published
- 2000
- Full Text
- View/download PDF
12. Effect of hearing intervention on communicative function: A secondary analysis of the ACHIEVE randomized controlled trial.
- Author
-
Sanchez VA, Arnold ML, Garcia Morales EE, Reed NS, Faucette S, Burgard S, Calloway HN, Coresh J, Deal JA, Goman AM, Gravens-Mueller L, Hayden KM, Huang AR, Mitchell CM, Mosley TH Jr, Pankow JS, Pike JR, Schrack JA, Sherry L, Weycker JM, Lin FR, and Chisolm TH
- Subjects
- Humans, Aged, Male, Female, Aged, 80 and over, Communication, Cognitive Dysfunction prevention & control, Hearing Aids, Hearing Loss rehabilitation, Hearing Loss prevention & control
- Abstract
Background: The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) Study was designed to determine the effects of a best-practice hearing intervention on cognitive decline among community-dwelling older adults. Here, we conducted a secondary analysis of the ACHIEVE Study to investigate the effect of hearing intervention on self-reported communicative function., Methods: The ACHIEVE Study is a parallel-group, unmasked, randomized controlled trial of adults aged 70-84 years with untreated mild-to-moderate hearing loss and without substantial cognitive impairment. Participants were randomly assigned (1:1) to a hearing intervention (audiological counseling and provision of hearing aids) or a control intervention of health education (individual sessions with a health educator covering topics on chronic disease prevention) and followed semiannually for 3 years. Self-reported communicative function was measured with the Hearing Handicap Inventory-Elderly Screening version (HHIE-S, range 0-40, higher scores indicate greater impairment). Effect of hearing intervention versus control on HHIE-S was analyzed through an intention-to-treat model controlling for known covariates., Results: HHIE-S improved after 6-months with hearing intervention compared to control, and continued to be better through 3-year follow-up. We estimated a difference of -8.9 (95% CI: -10.4, -7.5) points between intervention and control groups in change in HHIE-S score from baseline to 6 months, -9.3 (95% CI: -10.8, -7.9) to Year 1, -8.4 (95% CI: -9.8, -6.9) to Year 2, and - 9.5 (95% CI: -11.0, -8.0) to Year 3. Other prespecified sensitivity analyses that varied analytical parameters did not change the observed results., Conclusions: Hearing intervention improved self-reported communicative function compared to a control intervention within 6 months and with effects sustained through 3 years. These findings suggest that clinical recommendations for older adults with hearing loss should encourage hearing intervention that could benefit communicative function and potentially have positive downstream effects on other aspects of health., (© 2024 The Author(s). Journal of the American Geriatrics Society published by Wiley Periodicals LLC on behalf of The American Geriatrics Society.)
- Published
- 2024
- Full Text
- View/download PDF
13. Recruitment and baseline data of the Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study: A randomized trial of a hearing loss intervention for reducing cognitive decline.
- Author
-
Reed NS, Gravens-Mueller L, Huang AR, Goman AM, Mitchell CM, Arnold ML, Bolton S, Burgard S, Chisolm TH, Couper D, Deal JA, Evans J, Faucette S, Glynn NW, Gmelin T, Hayden KM, Miller E, Minotti M, Mosley T, Naylor S, Pankow JS, Pike JR, Sanchez VA, Schrack JA, Coresh J, and Lin FR
- Abstract
Introduction: Hearing loss is highly prevalent among older adults and independently associated with cognitive decline. The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a multicenter randomized control trial (partially nested within the infrastructure of an observational cohort study, the Atherosclerosis Risk in Communities [ARIC] study) to determine the efficacy of best-practice hearing treatment to reduce cognitive decline over 3 years. The goal of this paper is to describe the recruitment process and baseline results., Methods: Multiple strategies were used to recruit community-dwelling 70-84-year-old participants with adult-onset hearing loss who were free of substantial cognitive impairment from the parent ARIC study and de novo from the surrounding communities into the trial. Participants completed telephone screening, an in-person hearing, vision, and cognitive screening, and a comprehensive hearing assessment to determine eligibility., Results: Over a 24-month period, 3004 telephone screenings resulted in 2344 in-person hearing, vision, and cognition screenings and 1294 comprehensive hearing screenings. Among 1102 eligible, 977 were randomized into the trial (median age = 76.4 years; 53.5% female; 87.8% White; 53.3% held a Bachelor's degree or higher). Participants recruited through the ARIC study were recruited much earlier and were less likely to report hearing loss interfered with their quality of life relative to participants recruited de novo from the community. Minor differences in baseline hearing or health characteristics were found by recruitment route (i.e., ARIC study or de novo) and by study site., Discussion: The ACHIEVE study successfully completed enrollment over 2 years that met originally projected rates of recruitment. Substantial operational and scientific efficiencies during study startup were achieved through embedding this trial within the infrastructure of a longstanding and well-established observational study., Highlights: The ACHIEVE study tests the effect of hearing intervention on cognitive decline.The study is partially nested within an existing cohort study.Over 2 years, 977 participants recruited and enrolled.Eligibility assessed by telephone and in-person for hearing, vision, and cognitive screening.The ACHIEVE study findings will have significant public health implications., Competing Interests: Dr. Reed reported serving on the scientific advisory boards of Neosensory. Dr. Lin reported being a consultant to Frequency Therapeutics and Apple and being the director of a research center funded in part by a philanthropic gift from Cochlear Ltd to the Johns Hopkins Bloomberg School of Public Health. Dr. Lin is also a board member of the nonprofit Access HEARS. Dr. Sanchez reported industry funding related to consulting or research support from Otonomy Inc., Autifony Therapeutics Ltd., Boehringer Ingelheim, Frequency Therapeutics Ltd., Pipeline Therapeutics, Aerin Medical, Oticon Medical, Helen of Troy Ltd., Sonova Holding AG, and Phonak USA. Theresa Gmelin reports funding by The National Institute on Aging, Epidemiology of Aging training grant at the University of Pittsburgh T32 AG000181. All other authors report no relevant disclosures. Author disclosures are available in the Supporting information, (© 2024 The Authors. Alzheimer's & Dementia: Translational Research & Clinical Interventions published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)
- Published
- 2024
- Full Text
- View/download PDF
14. Description of the Baseline Audiologic Characteristics of the Participants Enrolled in the Aging and Cognitive Health Evaluation in Elders Study.
- Author
-
Sanchez VA, Arnold ML, Betz JF, Reed NS, Faucette S, Anderson E, Burgard S, Coresh J, Deal JA, Eddins AC, Goman AM, Glynn NW, Gravens-Mueller L, Hampton J, Hayden KM, Huang AR, Liou K, Mitchell CM, Mosley TH Jr, Neil HN, Pankow JS, Pike JR, Schrack JA, Sherry L, Teece KH, Witherell K, Lin FR, and Chisolm TH
- Abstract
Purpose: The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a randomized clinical trial designed to determine the effects of a best-practice hearing intervention versus a successful aging health education control intervention on cognitive decline among community-dwelling older adults with untreated mild-to-moderate hearing loss. We describe the baseline audiologic characteristics of the ACHIEVE participants., Method: Participants aged 70-84 years ( N = 977; M = 76.8) were enrolled at four U.S. sites through two recruitment routes: (a) an ongoing longitudinal study and (b) de novo through the community. Participants underwent diagnostic evaluation including otoscopy, tympanometry, pure-tone and speech audiometry, speech-in-noise testing, and provided self-reported hearing abilities. Baseline characteristics are reported as frequencies (percentages) for categorical variables or medians (interquartiles, Q1-Q3) for continuous variables. Between-groups comparisons were conducted using chi-square tests for categorical variables or Kruskal-Wallis test for continuous variables. Spearman correlations assessed relationships between measured hearing function and self-reported hearing handicap.
age = 76.8) were enrolled at four U.S. sites through two recruitment routes: (a) an ongoing longitudinal study and (b) de novo through the community. Participants underwent diagnostic evaluation including otoscopy, tympanometry, pure-tone and speech audiometry, speech-in-noise testing, and provided self-reported hearing abilities. Baseline characteristics are reported as frequencies (percentages) for categorical variables or medians (interquartiles, Q1-Q3) for continuous variables. Between-groups comparisons were conducted using chi-square tests for categorical variables or Kruskal-Wallis test for continuous variables. Spearman correlations assessed relationships between measured hearing function and self-reported hearing handicap., Results: The median four-frequency pure-tone average of the better ear was 39 dB HL, and the median speech-in-noise performance was a 6-dB SNR loss, indicating mild speech-in-noise difficulty. No clinically meaningful differences were found across sites. Significant differences in subjective measures were found for recruitment route. Expected correlations between hearing measurements and self-reported handicap were found., Conclusions: The extensive baseline audiologic characteristics reported here will inform future analyses examining associations between hearing loss and cognitive decline. The final ACHIEVE data set will be publicly available for use among the scientific community., Supplemental Material: https://doi.org/10.23641/asha.24756948.- Published
- 2024
- Full Text
- View/download PDF
15. Development, assessment, and monitoring of audiologic treatment fidelity in the aging and cognitive health evaluation in elders (ACHIEVE) randomised controlled trial.
- Author
-
Arnold ML, Haley W, Lin FR, Faucette S, Sherry L, Higuchi K, Witherell K, Anderson E, Reed NS, Chisolm TH, and Sanchez VA
- Subjects
- Aged, Aging, Cognition, Humans, Audiology, Research Design
- Abstract
Objective: Studies investigating hearing interventions under-utilise and under-report treatment fidelity planning, implementation, and assessment. This represents a critical gap in the field that has the potential to impede advancements in the successful dissemination and implementation of interventions. Thus, our objective was to describe treatment fidelity planning and implementation for hearing intervention in the multi-site Ageing and Cognitive Health Evaluation in Elders (ACHIEVE) randomised controlled trial., Design: Our treatment fidelity plan was based on a framework defined by the National Institutes of Health Behaviour Change Consortium (NIH BCC), and included strategies to enhance study design, provider training, and treatment delivery, receipt, and enactment., Study Sample: To assess the fidelity of the ACHIEVE hearing intervention, we distributed a checklist containing criteria from each NIH BCC core treatment fidelity category to nine raters., Results: The ACHIEVE hearing intervention fidelity plan satisfied 96% of NIH BCC criteria. Our assessment suggested a need for including clear, objective definitions of provider characteristics and non-treatment aspects of intervention delivery in future fidelity plans., Conclusions: The ACHIEVE hearing intervention fidelity plan can serve as a framework for the application of NIH BCC fidelity strategies for future studies and enhance the ability of researchers to reliably implement evidence-based interventions.
- Published
- 2022
- Full Text
- View/download PDF
16. Reverse Translation of US Food and Drug Administration Reviews of Oncology New Molecular Entities Approved in 2011-2017: Lessons Learned for Anticancer Drug Development.
- Author
-
Faucette S, Wagh S, Trivedi A, Venkatakrishnan K, and Gupta N
- Subjects
- Antineoplastic Agents therapeutic use, Drug Interactions, Electrocardiography drug effects, Humans, Product Surveillance, Postmarketing, United States, United States Food and Drug Administration legislation & jurisprudence, Antineoplastic Agents pharmacology, Drug Approval, Drug Development methods, Neoplasms drug therapy, Translational Research, Biomedical methods
- Published
- 2018
- Full Text
- View/download PDF
17. A phase I dose-escalation study of TAK-733, an investigational oral MEK inhibitor, in patients with advanced solid tumors.
- Author
-
Adjei AA, LoRusso P, Ribas A, Sosman JA, Pavlick A, Dy GK, Zhou X, Gangolli E, Kneissl M, Faucette S, Neuwirth R, and Bózon V
- Subjects
- Adult, Aged, Colonic Neoplasms metabolism, Extracellular Signal-Regulated MAP Kinases blood, Female, Humans, MAP Kinase Kinase 1 antagonists & inhibitors, MAP Kinase Kinase 2 antagonists & inhibitors, Male, Maximum Tolerated Dose, Melanoma metabolism, Middle Aged, Phosphorylation drug effects, Skin Neoplasms metabolism, Treatment Outcome, Uveal Neoplasms metabolism, Young Adult, Antineoplastic Agents adverse effects, Antineoplastic Agents pharmacokinetics, Antineoplastic Agents pharmacology, Antineoplastic Agents therapeutic use, Colonic Neoplasms drug therapy, Melanoma drug therapy, Protein Kinase Inhibitors adverse effects, Protein Kinase Inhibitors pharmacokinetics, Protein Kinase Inhibitors pharmacology, Protein Kinase Inhibitors therapeutic use, Pyridones adverse effects, Pyridones pharmacokinetics, Pyridones pharmacology, Pyridones therapeutic use, Pyrimidinones adverse effects, Pyrimidinones pharmacokinetics, Pyrimidinones pharmacology, Pyrimidinones therapeutic use, Skin Neoplasms drug therapy, Uveal Neoplasms drug therapy
- Abstract
Purpose TAK-733, an investigational, selective, allosteric MEK1/2 inhibitor, has demonstrated antitumor effects against multiple cancer cell lines and xenograft models. This first-in-human study investigated TAK-733 in patients with solid tumors. Methods Patients received oral TAK-733 once daily on days 1-21 in 28-day treatment cycles. Adverse events (AEs) were graded using the Common Terminology Criteria for AEs version 3.0. Response was assessed using RECIST v1.1. Blood samples for TAK-733 pharmacokinetics and pharmacodynamics (inhibition of ERK phosphorylation) were collected during cycle 1. Results Fifty-one patients received TAK-733 0.2-22 mg. Primary diagnoses included uveal melanoma (24 %), colon cancer (22 %), and cutaneous melanoma (10 %). Four patients had dose-limiting toxicities of dermatitis acneiform, plus fatigue and pustular rash in one patient, and stomatitis in one patient. The maximum tolerated dose was 16 mg. Common drug-related AEs included dermatitis acneiform (51 %), diarrhea (29 %), and increased blood creatine phosphokinase (20 %); grade ≥ 3 AEs were reported in 27 (53 %) patients. Median T
max was 3 h; systemic exposure increased less than dose-proportionally over the dose range 0.2-22 mg. On day 21 maximum inhibition of ERK phosphorylation in peripheral blood mononuclear cells of 46-97 % was seen in patients receiving TAK-733 ≥ 8.4 mg. Among 41 response-evaluable patients, 2 (5 %) patients with cutaneous melanoma (one with BRAF L597R mutant melanoma) had partial responses. Conclusions TAK-733 had a generally manageable toxicity profile up to the maximum tolerated dose, and showed the anticipated pharmacodynamic effect of sustained inhibition of ERK phosphorylation. Limited antitumor activity was demonstrated. Further investigation is not currently planned., Competing Interests: Compliance with ethical standards Conflicts of interest AR has acted as a consultant for and has received honoraria from Amgen, Compugen, Flexus, GSK, Genentech, and Merck, and holds stock in Novartis and Kite Pharma. JAS has acted as a consultant for Millennium Pharmaceuticals, Inc., Merck, and Amgen, and has received honorarium from Millennium Pharmaceuticals, Inc. The institution of JAS has also received grants from Bristol-Myers Squibb, GSK, and Millennium Pharmaceuticals, Inc. XZ, SF, RN, MK, EG and VB were employees of Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited. AAA, PL, AP, and GKD have no conflicts of interest to disclose. Funding The work was supported by Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informed consent Informed consent was obtained from all individual participants included in the study.- Published
- 2017
- Full Text
- View/download PDF
18. A phase I trial defining the maximum tolerated systemic exposure of topotecan in combination with Carboplatin and Etoposide in extensive stage small cell lung cancer.
- Author
-
Gillenwater HH, McCune JS, Lindley C, Faucette S, Shord S, Donahue A, Socinski MA, Stewart CF, Zamboni WC, Kirstein MN, and Moore D
- Subjects
- Adult, Aged, Antineoplastic Agents administration & dosage, Antineoplastic Agents adverse effects, Antineoplastic Agents pharmacokinetics, Antineoplastic Combined Chemotherapy Protocols adverse effects, Area Under Curve, Carboplatin administration & dosage, Carboplatin adverse effects, Carboplatin pharmacokinetics, Carcinoma, Small Cell mortality, Drug Administration Schedule, Etoposide administration & dosage, Etoposide adverse effects, Etoposide pharmacokinetics, Female, Humans, Lung Neoplasms mortality, Male, Middle Aged, Survival, Topotecan administration & dosage, Topotecan adverse effects, Topotecan pharmacokinetics, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Carcinoma, Small Cell drug therapy, Lung Neoplasms drug therapy, Maximum Tolerated Dose
- Abstract
Purpose: Topotecan is active in relapsed small cell lung cancer; thus, its addition to the standard carboplatin-etoposide regimen may improve outcomes in extensive-stage small cell lung cancer (ES-SCLC) patients. Significant interpatient variability in the topotecan systemic exposure results when it is dosed based on body surface area (mg/m2). The purpose of this Phase I trial was to determine the maximally tolerated systemic exposure (MTSE) of topotecan in combination with carboplatin and etoposide., Methods: Thirty-four chemotherapy-naïve ES-SCLC patients received topotecan in combination with carboplatin AUC 5 mg/mL*min and oral etoposide 100 mg/m2/day. Topotecan was administered as a 30-minute infusion either on Days 1-5 or Days 1-3 and the dosage was individualized to attain a topotecan lactone AUC range (ng/mL*hr) in successive patient cohorts from 7 to 23; 24 to 36; 37 to 53; 54 to 66., Results: The majority (67 percent) of the measured topotecan AUCs were within target range. Overall, 8 of 34 patients experienced Cycle 1 dose-limiting toxicity (DLT), either neutropenia or thrombocytopenia. Carboplatin administration prior to topotecan resulted in 2 of 6 patients having Cycle 1 DLT. When the administration sequence was changed (topotecan, carboplatin, etoposide), Cycle 1 hematologic toxicity decreased; however, the maximum topotecan lactone AUC of 24-36 ng/mL*hr (median dose 0.82 mg/m2) had significant cumulative hematologic toxicity. The number of topotecan doses were reduced from 5 to 3, which resulted in a maximum topotecan lactone AUC of 37 to 53 ng/mL*hr with only 1 of 6 patients having Cycle 1 DLT. Overall response rate was 71 percent with median survival of 10.8 months., Conclusion: It is feasible to target topotecan lactone AUC in adult ES-SCLC patients. However, this triplet regimen resulted in considerable hematologic toxicity and has a median survival comparable to carboplatin-etoposide. Alternative, less toxic regimens should be investigated for improving survival in ES-SCLC.
- Published
- 2005
- Full Text
- View/download PDF
19. Human constitutive androstane receptor mediates induction of CYP2B6 gene expression by phenytoin.
- Author
-
Wang H, Faucette S, Moore R, Sueyoshi T, Negishi M, and LeCluyse E
- Subjects
- Animals, Aryl Hydrocarbon Hydroxylases genetics, Cells, Cultured, Constitutive Androstane Receptor, Cytochrome P-450 CYP2B6, Enhancer Elements, Genetic, Genes, Reporter, Hepatocytes cytology, Hepatocytes drug effects, Hepatocytes physiology, Humans, Mice, Mice, Knockout, Oxidoreductases, N-Demethylating genetics, Pregnane X Receptor, Promoter Regions, Genetic, Protein Transport physiology, Receptors, Cytoplasmic and Nuclear genetics, Receptors, Steroid genetics, Receptors, Steroid metabolism, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Transcription Factors genetics, Anticonvulsants pharmacology, Aryl Hydrocarbon Hydroxylases metabolism, Gene Expression Regulation drug effects, Oxidoreductases, N-Demethylating metabolism, Phenytoin pharmacology, Receptors, Cytoplasmic and Nuclear metabolism, Transcription Factors metabolism
- Abstract
Compared with its rodent orthologs, little is known about the chemical specificity of human constitutive androstane receptor (hCAR) and its regulation of hepatic enzyme expression. Phenytoin (PHY), a widely used antiepileptic drug, is a potent inducer of CYP2B6 in primary human hepatocytes, but does not activate human pregnane X receptor (PXR) significantly in cell-based transfection assays at the same concentrations associated with potent induction of CYP2B6. Based on this observation, we hypothesized that PHY may be a selective activator of hCAR. In primary human hepatocytes, expression of CYP2B6 reporter genes containing phenobarbital-responsive enhancer module (PBREM) or PBREM/xenobiotic-responsive enhancer module (XREM) response elements were activated up to 14- and 28-fold, respectively, by 50 microm PHY. By contrast, parallel experiments in HepG2 cell lines co-transfected with an hPXR expression vector did not show increased reporter activity. These results indicated that a PXR-independent pathway, which is retained in primary hepatocytes, is responsible for PHY induction of CYP2B6. Further experiments revealed that PHY effectively translocates hCAR from the cytoplasm into the nucleus in both primary human hepatocytes and CAR(-/-) mice. Compared with vehicle controls, PHY administration significantly increased CYP2B6 reporter gene expression, when this reporter construct was delivered together with hCAR expression vector into CAR(-/-) mice. However, PHY did not increase reporter gene expression in CAR(-/-) mice in the absence of hCAR vector, implying that CAR is essential for mediating PHY induction of CYP2B6 gene expression. Taken together, these observations demonstrate that, in contrast to most of the known CYP2B6 inducers, PHY is a selective activator of CAR in humans.
- Published
- 2004
- Full Text
- View/download PDF
20. A novel distal enhancer module regulated by pregnane X receptor/constitutive androstane receptor is essential for the maximal induction of CYP2B6 gene expression.
- Author
-
Wang H, Faucette S, Sueyoshi T, Moore R, Ferguson S, Negishi M, and LeCluyse EL
- Subjects
- Amino Acid Motifs, Animals, Blotting, Western, Cells, Cultured, Constitutive Androstane Receptor, Cyclophosphamide pharmacology, Cytochrome P-450 CYP2B6, Dimerization, Genes, Reporter, Hepatocytes metabolism, Humans, Ifosfamide pharmacology, Ligands, Liver metabolism, Luciferases metabolism, Mice, Microsomes, Liver metabolism, Mutagenesis, Site-Directed, Phenobarbital pharmacology, Plasmids metabolism, Pregnane X Receptor, Promoter Regions, Genetic, Protein Binding, Rifampin pharmacology, Transcription, Genetic, Transcriptional Activation, Transfection, Tumor Cells, Cultured, Xenobiotics pharmacology, Aryl Hydrocarbon Hydroxylases biosynthesis, Aryl Hydrocarbon Hydroxylases genetics, Gene Expression Regulation, Oxidoreductases, N-Demethylating biosynthesis, Oxidoreductases, N-Demethylating genetics, Receptors, Cytoplasmic and Nuclear metabolism, Receptors, Steroid metabolism, Transcription Factors metabolism
- Abstract
CYP2B6 plays an important role in the metabolism of a variety of structurally unrelated xenobiotics, including the anticancer drugs cyclophosphamide and ifosfamide. Previous studies have shown that the nuclear receptors constitutive androstane receptor (CAR) and pregnane X receptor (PXR) are involved in the transcriptional regulation of CYP2B genes through the phenobarbital-responsive enhancer module (PBREM). However, for human CYP2B6 the relatively weak response of the PBREM to PXR and CAR activation in transfection assays fails to describe the potent induction observed in primary human hepatocyte cultures. In this report, a novel nuclear receptor response module located -8.5 kilobases upstream from the CYP2B6 encoding region is described. Several potential PXR/CAR binding motifs were identified within the distal regulatory cluster. In electrophoretic mobility shift assays, one DR4 motif showed the strongest binding to both PXR and CAR. Transient transfection assays in HepG2 cells demonstrated that the novel distal response cluster could be activated by PXR and CAR. In primary human hepatocytes, both PBREM and the distal responsive element were activated individually by endogenous nuclear receptors upon exposure to prototypical inducers. However, in both HepG2 cells and primary human hepatocytes maximal reporter activation was observed in a construct containing both PBREM and the distal responsive element. In mouse tail-vein injection experiments, a construct containing both the distal responsive element and the proximal PBREM exhibited a strong synergistic expression in phenobarbital-treated mice. These results show that a novel xenobiotic-responsive enhancer module in the distal region of the CYP2B6 promoter (CYP2B6-XREM) together with the PBREM mediates optimal drug-induced expression of CYP2B6.
- Published
- 2003
- Full Text
- View/download PDF
21. The effect of cyclophosphamide with and without dexamethasone on cytochrome P450 3A4 and 2B6 in human hepatocytes.
- Author
-
Lindley C, Hamilton G, McCune JS, Faucette S, Shord SS, Hawke RL, Wang H, Gilbert D, Jolley S, Yan B, and LeCluyse EL
- Subjects
- Aryl Hydrocarbon Hydroxylases biosynthesis, Cells, Cultured, Cytochrome P-450 CYP2B6, Cytochrome P-450 CYP3A, Cytochrome P-450 Enzyme System biosynthesis, Dose-Response Relationship, Drug, Drug Combinations, Enzyme Activation drug effects, Enzyme Induction drug effects, Hepatocytes enzymology, Humans, Oxidoreductases, N-Demethylating biosynthesis, Aryl Hydrocarbon Hydroxylases metabolism, Cyclophosphamide pharmacology, Cytochrome P-450 Enzyme System metabolism, Dexamethasone pharmacology, Hepatocytes drug effects, Oxidoreductases, N-Demethylating metabolism
- Abstract
The purpose of this study was to characterize the concentration-response effects of cyclophosphamide (CPA) with and without dexamethasone (DEX; 10 microM) on the expression of CYP3A4 and CYP2B6 in cultured human hepatocytes at concentrations representative of standard- and high-dose CPA therapy (25 to 750 microM). CPA produced concentration-dependent increases in CYP3A4 and CYP2B6 activity and immunoreactive protein that peaked at 250 and 125 microM, respectively, and declined thereafter. The inductive effect of CPA alone and in combination with DEX was greater in magnitude for CYP2B6 compared with CYP3A4. To further examine the inductive effect of CPA on CYP3A4, CPA (250 microM) and DEX (10 microM) alone and in combination were examined in 10 hepatocyte preparations. The combination of CPA and DEX yielded higher rates of 6beta-hydroxytestosterone formation than either agent alone. However, the effect was less than additive in human hepatocyte cultures with relatively high baseline CYP3A4 activity and additive or synergistic in human hepatocyte cultures with relatively low baseline CYP3A4 activity. Induction index was highly correlated with CYP3A4 baseline activity for both CPA (r(2) = 0.75) and CPA plus DEX (r(2) = 0.85). To investigate the potential mechanism for CPA-induced increases in CYP3A4 activity, the ability of CPA alone and in combination with DEX to activate pregnane X receptor (PXR) was explored using transient transfection assays. CPA produced a dose-dependent increase in PXR activation that was maximal at the highest CPA concentration studied (500 microM). The addition of DEX to CPA resulted in a minor increase in PXR activation compared with CPA alone. These results indicate that CPA alone and in combination with DEX differentially induces the expression of CYP3A4 and 2B in a concentration-dependent manner, which may be mediated partially through activation of PXR. The impact of these effects on the efficacy and toxicity of CPA therapy warrants further investigation.
- Published
- 2002
- Full Text
- View/download PDF
22. Evaluation of the contribution of cytochrome P450 3A4 to human liver microsomal bupropion hydroxylation.
- Author
-
Faucette SR, Hawke RL, Shord SS, Lecluyse EL, and Lindley CM
- Subjects
- Cytochrome P-450 CYP3A, Cytochrome P-450 Enzyme Inhibitors, DNA biosynthesis, Humans, Hydroxylation, In Vitro Techniques, Kinetics, Mixed Function Oxygenases antagonists & inhibitors, Antidepressive Agents, Second-Generation metabolism, Bupropion metabolism, Cytochrome P-450 Enzyme System metabolism, Microsomes, Liver enzymology, Mixed Function Oxygenases metabolism
- Abstract
The purpose of this investigation was to evaluate the role of cytochrome P450 (CYP) 3A4 in human liver microsomal bupropion (BUP) hydroxylation. Across the BUP concentration range of 0.075 to 12 mM, cDNA-expressed CYP3A4 demonstrated BUP hydroxylase activity only when incubated with concentrations > or =4 mM. When assayed at 12 mM BUP, cDNA-expressed CYP3A4 catalyzed BUP hydroxylation at a 30-fold lower rate than cDNA-expressed CYP2B6 (0.2 versus 7 pmol/min/pmol of P450). Among a panel of 16 human liver microsomes (HLMs), BUP hydroxylase activity varied 80-fold when assayed at 500 microM and did not strongly correlate with testosterone 6beta-hydroxylase activity when assayed at 250 microM testosterone (r(2) = 0.39), nor with CYP3A4 protein expression. A selective CYP3A4 inhibitor, troleandomycin (TAO), did not significantly alter rates of BUP hydroxylation when assayed in a moderate activity HLM at 10 to 2000 microM BUP, as reflected by a similarity in the kinetic parameters of BUP hydroxylation in the absence or presence of TAO. In addition, the same range of TAO concentrations (0.025-100 microM) that inhibited testosterone 6beta-hydroxylation in a concentration-dependent manner (46-81%) in pooled HLMs produced negligible inhibition (7%) of BUP hydroxylation when assayed at 500 microM BUP. These results suggest that CYP3A4 does not significantly catalyze BUP hydroxylation. Furthermore, these results complement recent data supporting selectivity of BUP hydroxylation for CYP2B6 at 500 microM BUP.
- Published
- 2001
23. Validation of bupropion hydroxylation as a selective marker of human cytochrome P450 2B6 catalytic activity.
- Author
-
Faucette SR, Hawke RL, Lecluyse EL, Shord SS, Yan B, Laethem RM, and Lindley CM
- Subjects
- Animals, Antibodies, Monoclonal pharmacology, Biomarkers, Catalysis, Cell Line, Cytochrome P-450 CYP2B6, Cytochrome P-450 Enzyme System genetics, Cytochrome P-450 Enzyme System immunology, Dose-Response Relationship, Drug, Humans, Hydroxylation drug effects, Isoenzymes genetics, Isoenzymes immunology, Isoenzymes metabolism, Kinetics, Microsomes, Liver drug effects, Microsomes, Liver enzymology, Microsomes, Liver metabolism, Oxidoreductases, N-Demethylating genetics, Oxidoreductases, N-Demethylating immunology, Recombinant Proteins metabolism, Reproducibility of Results, Aryl Hydrocarbon Hydroxylases, Bupropion metabolism, Cytochrome P-450 Enzyme System metabolism, Oxidoreductases, N-Demethylating metabolism
- Abstract
The purpose of this study was to establish bupropion (BUP) hydroxylation as a selective in vitro marker of cytochrome P450 (CYP) 2B6 catalytic activity. Among a panel of 16 human liver microsomes (HLMs), BUP hydroxylase activity varied 80-fold when assayed at 500 microM substrate and significantly correlated with CYP2B6 blotting density (r(2) = 0.99) and S-mephenytoin N-demethylase activity (r(2) = 0.98). Kinetic analysis of BUP hydroxylation was performed in a subset of seven HLMs representative of the 80-fold range in activity. Sigmoidal kinetics suggestive of allosteric activation was observed in five HLMs exhibiting low or high activity; the mean apparent K(m) for BUP hydroxylation in these HLMs (130 microM) was similar to the K(m) for cDNA-expressed CYP2B6 (156 microM). Nonsaturable, biphasic kinetics was observed in two HLMs exhibiting low activity. Among a panel of cDNA-expressed P450 isoforms, CYP2B6 and CYP2E1 demonstrated the highest rates of BUP hydroxylation at 12 mM BUP (7.0 and 2.4 pmol/min/pmol of P450, respectively). The relative contributions of CYP2B6 and CYP2E1 to BUP hydroxylation were estimated by using immunoinhibitory monoclonal antibodies (MAB) to these enzymes. MAB-2B6 produced 88% maximum inhibition of BUP hydroxylation when assayed at 12 mM BUP in a high activity HLM, whereas MAB-2E1 produced 81% maximum inhibition in a low activity HLM. However, negligible inhibition by MAB-2E1 was observed when low and high activity HLMs were assayed at 500 microM BUP. These results demonstrate selectivity of BUP hydroxylation for CYP2B6 at 500 microM BUP, thereby validating its use as a diagnostic in vitro marker of CYP2B6 catalytic activity.
- Published
- 2000
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.