FDA draft guidance on adaptive design clinical trials: Pfizer's perspective.

abstract：:Failure to recognize the serious implications of heterogeneous correlations and disregard of the multiple test problem in interpreting the results from repeated measurements ANOVA of any single primary outcome measure can produce false-positive error rates that are more than five times the alpha level that is reported...

journal_title：Journal of biopharmaceutical statistics

authors： Overall JE,Doyle SR

更新日期：1996-03-01 00:00:00

abstract：:We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models...

journal_title：Journal of biopharmaceutical statistics

authors： Franchetti Y,Anderson SJ,Sampson AR

更新日期：2013-01-01 00:00:00

abstract：:Bowker's test, a generalization of McNemar's test, performs well under the hypothesis of symmetry, but the estimator of variance used in the test is biased when the table is asymmetric and this calls into question the test's performance in non-null situations. We seek an alternative to Bowker's test in search of metho...

journal_title：Journal of biopharmaceutical statistics

authors： May WL,Johnson WD

更新日期：2001-02-01 00:00:00

abstract：:This article deals with seven special issues related to the assumptions, applicability, and practical use of formulas for calculating power or sample size, respectively, for comparative clinical trials with time-to-event endpoints, with particular focus on the well-known Freedman and Schoenfeld methods. All problems a...

journal_title：Journal of biopharmaceutical statistics

authors： Abel UR,Jensen K,Karapanagiotou-Schenkel I,Kieser M

更新日期：2015-01-01 00:00:00

abstract：:A mathematical model is described for selecting combinations of chemotherapeutic drugs in order to maximize antitumor dose intensity subject to constraints on toxicity to normal organ systems. Determination of which drugs to combine and in what proportions to combine them offers combinatorially huge numbers of possibi...

journal_title：Journal of biopharmaceutical statistics

authors： Simon R,Korn EL

更新日期：1991-01-01 00:00:00

abstract：:In clinical trials of drug development, patients are often followed for a certain period of time, and the outcome variables are measured at scheduled time intervals. The main interest of the trial is the treatment efficacy at a prespecified time point, which is often the last visit. In such trials, patient dropout is ...

journal_title：Journal of biopharmaceutical statistics

authors： Kong F,Chen YF,Jin K

更新日期：2009-11-01 00:00:00

abstract：:Investigating the prevalence of a disease is an important topic in medical studies. Such investigations are usually based on the classification results of a group of subjects according to whether they have the disease. To classify subjects, screening tests that are inexpensive and nonintrusive to the test subjects are...

journal_title：Journal of biopharmaceutical statistics

authors： Tang ML,Qiu SF,Poon WY,Tang NS

更新日期：2012-01-01 00:00:00

abstract：:This article discusses the design of a clinical trial where a new treatment will be compared to a control. For a specific type of endpoint, there are a wide variety of test statistics that can be used. Also, the investigator must decide how many patients to accrue in each arm as well as the duration of the study. Afte...

journal_title：Journal of biopharmaceutical statistics

authors： Lawrence J

更新日期：2002-05-01 00:00:00

abstract：:This paper addresses the problem of analyzing multivariate response with the variates having different distributions. We use the generalized estimating equations proposed by Prentice and Zhao (1) to estimate mean and covariance parameters. Wald statistics are used to test hypotheses about the parameters. Data from a t...

journal_title：Journal of biopharmaceutical statistics

authors： May WL,Johnson WD

更新日期：1996-05-01 00:00:00

abstract：:The outcome selection of bioequivalence evaluations for abbreviated new drug applications results in bias towards unity of test-reference ratio estimates, and underestimation of intrasubject variability for the test drug product. In this study, the selection bias in the estimates of testreference ratio and intrasubjec...

journal_title：Journal of biopharmaceutical statistics

authors： Wang Y

更新日期：2000-08-01 00:00:00

abstract：:It is well known that there is strong relationship between HIV viral load and CD4 cell counts in AIDS studies. However, the relationship between them changes during the course of treatment and may vary among individuals. During treatments, some individuals may experience terminal events such as death. Because the term...

journal_title：Journal of biopharmaceutical statistics

authors： Lu T,Wang M,Liu G,Dong GH,Qian F

更新日期：2016-01-01 00:00:00

abstract：:The dose-response models for full agonists and for a particular type of partial agonist can be described by sigmoidal curves and bell-shaped curves, respectively. The methods currently used to evaluate the interaction of a full agonist and a partial agonist require a large number of experimental units and base their a...

journal_title：Journal of biopharmaceutical statistics

authors： Ghosh K,Shen ES,Arey BJ,López FJ

更新日期：1998-11-01 00:00:00

abstract：:During preclinical drug development, the immune system is specifically evaluated after prolonged treatment with drug candidates, because the immune system may be an important target system. The response of antibodies against a T-cell-dependent antigen is recommenced by the FDA and EMEA for the evaluation of immunosupp...

journal_title：Journal of biopharmaceutical statistics

authors： Shkedy Z,Straetemans R,Molenberghs G,Desmidt M,Vinken P,Goeminne N,Coussement W,Van Den Poel B,Bijnens L

更新日期：2005-01-01 00:00:00

abstract：:Four multidose animal carcinogenicity assay trend test procedures based on the chi-square, Hoel-Walburg, log-rank, and Peto procedures are compared under conditions of competing risks. A total of 42 different risk populations are simulated in which a simulated animal can contract one or more of five different tumor ty...

journal_title：Journal of biopharmaceutical statistics

authors： Graves TS

更新日期：1994-11-01 00:00:00

abstract：:We consider the problem of estimating a biomarker-based subgroup and testing for treatment effect in the overall population and in the subgroup after the trial. We define the best subgroup as the subgroup that maximizes the power for comparing the experimental treatment with the control. In the case of continuous outc...

journal_title：Journal of biopharmaceutical statistics

authors： Joshi N,Fine J,Chu R,Ivanova A

更新日期：2019-01-01 00:00:00

abstract：:We provide a set of formulas that allow the combination of separately performed analyses of population pharmacokinetic (PK) studies, without any further computational effort. More specifically, given the point estimates and uncertainties of two population PK analyses, the formulas provide the point estimates and uncer...

journal_title：Journal of biopharmaceutical statistics

authors： Dokoumetzidis A,Aarons L

更新日期：2008-01-01 00:00:00

abstract：:In this article, we show how to estimate a transition period for the evolvement of drug resistance to antiretroviral (ARV) drug or other related treatments in the framework of developing a Bayesian method for jointly analyzing time-to-event and longitudinal data. For HIV/AIDS longitudinal data, developmental trajector...

journal_title：Journal of biopharmaceutical statistics

authors： Dagne GA

更新日期：2018-01-01 00:00:00

abstract：:Stability testing is a procedure frequently used in the pharmaceutical industry to estimate the shelf life of a drug. Hereby, a standard problem of interest is whether or not to pool a given number of batches to assign a single shelf life for the combined batches. In this paper, we propose two modified methods for the...

journal_title：Journal of biopharmaceutical statistics

authors： Djira GD,Hothorn LA,Tsong Y

更新日期：2008-01-01 00:00:00

abstract：:We develop a Bayesian approach for estimating vaccine efficacy for susceptibility (VEs) and infectiousness (VEI) using outbreak size household data. Our method allows for heterogeneity in transmission probabilities due to factors that are related to individuals' characteristics, such as age, in addition to vaccination...

journal_title：Journal of biopharmaceutical statistics

authors： Davis XM,Waller LA,Haber M

更新日期：2006-01-01 00:00:00

abstract：:As more biologic products are going off patent protection, the development of follow-on biologics products has received much attention from both biotechnology industry and the regulatory agencies. Unlike small-molecule drug products, the development of biologic products is very different and variable via the manufactu...

journal_title：Journal of biopharmaceutical statistics

authors： Hsieh TC,Chow SC,Liu JP,Hsiao CF,Chi E

更新日期：2010-01-01 00:00:00

abstract：:Recently, two CPMP Points to Consider, one on adjustment for baseline covariates and the other on multiplicity issues in clinical trials, have included recommendations on the use of subgroup analysis for regulatory purposes. However, despite their regular use and regulatory attention, the validity and nature of subgro...

journal_title：Journal of biopharmaceutical statistics

authors： Grouin JM,Coste M,Lewis J

更新日期：2005-01-01 00:00:00

abstract：:The proportion ratio (PR) of a positive response between an experimental treatment and a standard treatment (or placebo) is often used to measure the relative treatment efficacy in a randomized clinical trial (RCT). For ethical reasons, it is almost inevitable to encounter some patients not complying with their assign...

journal_title：Journal of biopharmaceutical statistics

authors： Lui KJ,Chang KC

更新日期：2012-01-01 00:00:00

abstract：:The purpose of this paper is to describe, illustrate, and compare a number of different approaches to the analysis of repeated binary and categorical data. These approaches include empirical generalized least squares and generalized estimating equations, as well as traditional log-linear modeling methods. It is shown ...

journal_title：Journal of biopharmaceutical statistics

authors： Kenward MG,Jones B

更新日期：1992-01-01 00:00:00

abstract：:Some statistical methods applied to in vitro diagnostic tests for the three primary indications (screening, diagnosis, and monitoring) are discussed. Various examples with practical statistical applications are presented, including test for k by k ordered categorical matched-pair data for screening of cervical cancer,...

journal_title：Journal of biopharmaceutical statistics

authors： Lao CS

更新日期：1997-11-01 00:00:00

abstract：:The use of adaptive methods in clinical development has become very popular in recent years due to its flexibility in modifying trial procedures and/or statistical procedures of on-going clinical trials. Modifications to trial procedures are usually documented by protocol amendments. However, the actual patient popula...

journal_title：Journal of biopharmaceutical statistics

authors： Chow SC,Shao J

更新日期：2005-01-01 00:00:00

abstract：:This paper introduces exact permutation methods for use when there are independent clusters of data with arbitrary within-cluster correlation. To eliminate the problem of clustering, we randomly select a data point from each cluster and for this now independent data, and calculate our test statistic and the associated...

journal_title：Journal of biopharmaceutical statistics

authors： Follmann D,Fay M

更新日期：2010-07-01 00:00:00

abstract：:Administration of biological therapeutics can generate undesirable immune responses that may induce anti-drug antibodies (ADAs). Immunogenicity can negatively affect patients, ranging from mild reactive effect to hypersensitivity reactions or even serious autoimmune diseases. Assessment of immunogenicity is critical a...

journal_title：Journal of biopharmaceutical statistics

authors： Zhang J,Yu B,Zhang L,Roskos L,Richman L,Yang H

更新日期：2015-01-01 00:00:00

abstract：:Assessment of quality of life (QOL) in clinical trials becomes a challenging task from the viewpoint of clinical biostatistics. The responses of the items for measuring QOL indices usually vary widely from patient to patient and from time to time. Measurement errors might be present in the responses of the items, and ...

journal_title：Journal of biopharmaceutical statistics

authors： Siddiqui O,Ali MW

更新日期：1999-11-01 00:00:00

abstract：:In this paper, a propensity score-integrated composite likelihood (PSCL) approach is developed for cases in which the control arm of a two-arm randomized controlled trial (RCT) (treated vs control) is augmented with patients from real-world data (RWD) containing both clinical outcomes and covariates at the patient-lev...

journal_title：Journal of biopharmaceutical statistics

authors： Chen WC,Wang C,Li H,Lu N,Tiwari R,Xu Y,Yue LQ

更新日期：2020-05-03 00:00:00

abstract：:Dunnett's many-to-one test is used frequently today, especially in dose-finding studies. Using Dunnett's test, the Type I error level for the comparison between the raw mean of the control and the raw means of the study drug groups can be exactly calculated for the normal data. However, this computability depends on t...

journal_title：Journal of biopharmaceutical statistics

authors： Shun Z,Silverberg A,Chang CK,Ouyang P

更新日期：2003-02-01 00:00:00