The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Wolf Rüdiger Schäbitz - One of the best experts on this subject based on the ideXlab platform.
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Analysis of early Phase and Subsequent Phase III stroke studies of neuroprotectants: outcomes and predictors for success
Experimental & Translational Stroke Medicine, 2014Co-Authors: Jens Minnerup, Heike Wersching, Matthias Schilling, Wolf Rüdiger SchäbitzAbstract:Background Efficacy of neuroprotective treatments for ischemic stroke was not convincingly demonstrated in clinical Phase III trials so far, whereas some preceding early Phase studies found neuroprotection to be beneficial. We aimed to determine the frequency with which Phase III studies are preceded by positive early Phase studies, and to identify characteristics of early Phase studies that are associated with correct prediction of Phase III studies. Methods We identified Phase III studies and corresponding early Phase studies of neuroprotective treatments for stroke. Data on study characteristics of early Phase trials were extracted and compared between studies that were classified according to their results as “false positive” and “true neutral” using logistic regression analysis. Results Forty-six Phase III studies and 59 corresponding early Phase studies were identified. Only one Phase III study was positive and this study was followed by a larger negative study. Twenty-two (37.3%) early Phase studies were considered to be false positive and 37 (62.7%) to be true neutral. None of the early Phase study characteristics were significantly associated with correct prediction of Phase III studies. Conclusions More than one third of early Phase studies on neuroprotective stroke treatments are false positive. Neither the results nor specific study design characteristics of early Phase stroke studies reliably predict success in Phase III trials. Further efforts are needed to improve early Phase studies regarding its predictability and to identify those early studies that should be advanced to Phase III trials.
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Analysis of early Phase and Subsequent Phase III stroke studies of neuroprotectants: outcomes and predictors for success.
Experimental & translational stroke medicine, 2014Co-Authors: Jens Minnerup, Heike Wersching, Matthias Schilling, Wolf Rüdiger SchäbitzAbstract:Background Efficacy of neuroprotective treatments for ischemic stroke was not convincingly demonstrated in clinical Phase III trials so far, whereas some preceding early Phase studies found neuroprotection to be beneficial. We aimed to determine the frequency with which Phase III studies are preceded by positive early Phase studies, and to identify characteristics of early Phase studies that are associated with correct prediction of Phase III studies.
Richard Simon - One of the best experts on this subject based on the ideXlab platform.
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a model to select chemotherapy regimens for Phase iii trials for extensive stage small cell lung cancer
Journal of the National Cancer Institute, 2000Co-Authors: Timothy T Chen, John P Chute, Ellen Feigal, Bruce E Johnson, Richard SimonAbstract:BACKGROUND: Many more Phase II studies have favorable outcomes than the Subsequent Phase III trials. We used historical data from Phase II and Phase III studies for patients with extensive-stage small-cell lung cancer (SCLC) to generate a statistical model to provide assistance in selecting chemotherapy regimens from Phase II studies for Subsequent use in Phase III randomized studies. METHODS: Information from 21 Phase III trials for patients with extensive-stage SCLC initiated during the period from 1972 through 1990 was reviewed to identify those that were preceded by Phase II studies of the same regimen. We used data from all the trial pairs to develop a statistical model in which the number of patients, the median survival of patients, and the number of deaths observed in the Phase II trial are used to estimate the statistical power of the Subsequent Phase III trial. All statistical tests were two-sided. RESULTS: Nine Phase II studies were identified that preceded Phase III trials of the same regimen. The regimens from two Phase II studies with the greatest expected power in the Phase III trial (0. 62 and 0.58) both demonstrated significantly prolonged survival when compared with standard treatment in Subsequent Phase III trials (P<. 001 and P =.002, respectively). The regimens from six of the other Phase II studies, for which the median power expected in the Phase III trial was 0.28 (range, 0.19-0.52), showed no difference when compared with standard treatment in a Phase III trial. CONCLUSIONS: Phase II studies for particular regimens that have an expected power of greater than 0.55 provide a reasonable basis for proceeding with a Phase III trial.
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A Model to Select Chemotherapy Regimens for Phase III Trials for Extensive-Stage Small-Cell Lung Cancer
Journal of the National Cancer Institute, 2000Co-Authors: Timothy T Chen, John P Chute, Ellen Feigal, Bruce E Johnson, Richard SimonAbstract:BACKGROUND: Many more Phase II studies have favorable outcomes than the Subsequent Phase III trials. We used historical data from Phase II and Phase III studies for patients with extensive-stage small-cell lung cancer (SCLC) to generate a statistical model to provide assistance in selecting chemotherapy regimens from Phase II studies for Subsequent use in Phase III randomized studies. METHODS: Information from 21 Phase III trials for patients with extensive-stage SCLC initiated during the period from 1972 through 1990 was reviewed to identify those that were preceded by Phase II studies of the same regimen. We used data from all the trial pairs to develop a statistical model in which the number of patients, the median survival of patients, and the number of deaths observed in the Phase II trial are used to estimate the statistical power of the Subsequent Phase III trial. All statistical tests were two-sided. RESULTS: Nine Phase II studies were identified that preceded Phase III trials of the same regimen. The regimens from two Phase II studies with the greatest expected power in the Phase III trial (0. 62 and 0.58) both demonstrated significantly prolonged survival when compared with standard treatment in Subsequent Phase III trials (P
Dae Won Cho - One of the best experts on this subject based on the ideXlab platform.
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fine size regulation of nanocrystalline anatase tio2via sol gel synthesis and Subsequent Phase transformation by calcination
New Journal of Chemistry, 2013Co-Authors: Kyung-jun Hwang, Jae-wook Lee, Seung-joon Yoo, Sinyoung Jeong, Dae Hong Jeong, Wang Geun Shim, Dae Won ChoAbstract:Nanocrystalline TiO2 particles were prepared via the sol–gel process. The particle size and nanostructure of the TiO2 sol were controlled through the ageing process accompanied by hydrolysis–polycondensation. The resultant TiO2 particles were analysed by BET, HR-TEM, PSA, TGA, turbidity, XRD, and zeta potential analyses. The TiO2 size increased with increasing ageing time and reaction temperature. A Phase transformation from anatase to rutile occurred with heat treatment at 500 °C. The Phase transformation is strongly influenced by the primary particle sizes of TiO2, which were characterised via XRD and Raman spectroscopic analyses.
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Fine size-regulation of nanocrystalline anatase-TiO2via sol–gel synthesis and Subsequent Phase transformation by calcination
New Journal of Chemistry, 2013Co-Authors: Kyung-jun Hwang, Jae-wook Lee, Seung-joon Yoo, Sinyoung Jeong, Dae Hong Jeong, Wang Geun Shim, Dae Won ChoAbstract:Nanocrystalline TiO2 particles were prepared via the sol–gel process. The particle size and nanostructure of the TiO2 sol were controlled through the ageing process accompanied by hydrolysis–polycondensation. The resultant TiO2 particles were analysed by BET, HR-TEM, PSA, TGA, turbidity, XRD, and zeta potential analyses. The TiO2 size increased with increasing ageing time and reaction temperature. A Phase transformation from anatase to rutile occurred with heat treatment at 500 °C. The Phase transformation is strongly influenced by the primary particle sizes of TiO2, which were characterised via XRD and Raman spectroscopic analyses.
Jens Minnerup - One of the best experts on this subject based on the ideXlab platform.
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Analysis of early Phase and Subsequent Phase III stroke studies of neuroprotectants: outcomes and predictors for success
Experimental & Translational Stroke Medicine, 2014Co-Authors: Jens Minnerup, Heike Wersching, Matthias Schilling, Wolf Rüdiger SchäbitzAbstract:Background Efficacy of neuroprotective treatments for ischemic stroke was not convincingly demonstrated in clinical Phase III trials so far, whereas some preceding early Phase studies found neuroprotection to be beneficial. We aimed to determine the frequency with which Phase III studies are preceded by positive early Phase studies, and to identify characteristics of early Phase studies that are associated with correct prediction of Phase III studies. Methods We identified Phase III studies and corresponding early Phase studies of neuroprotective treatments for stroke. Data on study characteristics of early Phase trials were extracted and compared between studies that were classified according to their results as “false positive” and “true neutral” using logistic regression analysis. Results Forty-six Phase III studies and 59 corresponding early Phase studies were identified. Only one Phase III study was positive and this study was followed by a larger negative study. Twenty-two (37.3%) early Phase studies were considered to be false positive and 37 (62.7%) to be true neutral. None of the early Phase study characteristics were significantly associated with correct prediction of Phase III studies. Conclusions More than one third of early Phase studies on neuroprotective stroke treatments are false positive. Neither the results nor specific study design characteristics of early Phase stroke studies reliably predict success in Phase III trials. Further efforts are needed to improve early Phase studies regarding its predictability and to identify those early studies that should be advanced to Phase III trials.
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Analysis of early Phase and Subsequent Phase III stroke studies of neuroprotectants: outcomes and predictors for success.
Experimental & translational stroke medicine, 2014Co-Authors: Jens Minnerup, Heike Wersching, Matthias Schilling, Wolf Rüdiger SchäbitzAbstract:Background Efficacy of neuroprotective treatments for ischemic stroke was not convincingly demonstrated in clinical Phase III trials so far, whereas some preceding early Phase studies found neuroprotection to be beneficial. We aimed to determine the frequency with which Phase III studies are preceded by positive early Phase studies, and to identify characteristics of early Phase studies that are associated with correct prediction of Phase III studies.
Timothy T Chen - One of the best experts on this subject based on the ideXlab platform.
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a model to select chemotherapy regimens for Phase iii trials for extensive stage small cell lung cancer
Journal of the National Cancer Institute, 2000Co-Authors: Timothy T Chen, John P Chute, Ellen Feigal, Bruce E Johnson, Richard SimonAbstract:BACKGROUND: Many more Phase II studies have favorable outcomes than the Subsequent Phase III trials. We used historical data from Phase II and Phase III studies for patients with extensive-stage small-cell lung cancer (SCLC) to generate a statistical model to provide assistance in selecting chemotherapy regimens from Phase II studies for Subsequent use in Phase III randomized studies. METHODS: Information from 21 Phase III trials for patients with extensive-stage SCLC initiated during the period from 1972 through 1990 was reviewed to identify those that were preceded by Phase II studies of the same regimen. We used data from all the trial pairs to develop a statistical model in which the number of patients, the median survival of patients, and the number of deaths observed in the Phase II trial are used to estimate the statistical power of the Subsequent Phase III trial. All statistical tests were two-sided. RESULTS: Nine Phase II studies were identified that preceded Phase III trials of the same regimen. The regimens from two Phase II studies with the greatest expected power in the Phase III trial (0. 62 and 0.58) both demonstrated significantly prolonged survival when compared with standard treatment in Subsequent Phase III trials (P<. 001 and P =.002, respectively). The regimens from six of the other Phase II studies, for which the median power expected in the Phase III trial was 0.28 (range, 0.19-0.52), showed no difference when compared with standard treatment in a Phase III trial. CONCLUSIONS: Phase II studies for particular regimens that have an expected power of greater than 0.55 provide a reasonable basis for proceeding with a Phase III trial.
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A Model to Select Chemotherapy Regimens for Phase III Trials for Extensive-Stage Small-Cell Lung Cancer
Journal of the National Cancer Institute, 2000Co-Authors: Timothy T Chen, John P Chute, Ellen Feigal, Bruce E Johnson, Richard SimonAbstract:BACKGROUND: Many more Phase II studies have favorable outcomes than the Subsequent Phase III trials. We used historical data from Phase II and Phase III studies for patients with extensive-stage small-cell lung cancer (SCLC) to generate a statistical model to provide assistance in selecting chemotherapy regimens from Phase II studies for Subsequent use in Phase III randomized studies. METHODS: Information from 21 Phase III trials for patients with extensive-stage SCLC initiated during the period from 1972 through 1990 was reviewed to identify those that were preceded by Phase II studies of the same regimen. We used data from all the trial pairs to develop a statistical model in which the number of patients, the median survival of patients, and the number of deaths observed in the Phase II trial are used to estimate the statistical power of the Subsequent Phase III trial. All statistical tests were two-sided. RESULTS: Nine Phase II studies were identified that preceded Phase III trials of the same regimen. The regimens from two Phase II studies with the greatest expected power in the Phase III trial (0. 62 and 0.58) both demonstrated significantly prolonged survival when compared with standard treatment in Subsequent Phase III trials (P
