Stochastic optimization of adaptive enrichment designs for two subpopulations.

abstract：:The Wilcoxon-Mann-Whitney (WMW) test is the most commonly used nonparametric method to compare two treatments when the underlying distribution of the outcome variable is not normally distributed. In the presence of stratum effects, the van Elteren (vE) test, a stratified WMW test, can be used to adjust for the stratum...

journal_title：Journal of biopharmaceutical statistics

authors： Qu Y,Zhao YD,Rahardja D

更新日期：2008-01-01 00:00:00

abstract：:During a clinical trial, balancing statistical and ethical considerations are important. Response-adaptive randomization methods use the information from past patients to increase the probability of the next patient receiving the better treatment while avoiding the statistical concern of selection bias. We compared th...

journal_title：Journal of biopharmaceutical statistics

authors： Piccorelli AV,Fraker SA

更新日期：2018-01-01 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：:In confidence interval estimation of the difference between two proportions with overdispersion due to positive correlations, the usual asymptotic normality-based method generally has lower coverage rates than desired, especially when sample size is moderate. Applying the concept of effective sample size to existing m...

journal_title：Journal of biopharmaceutical statistics

authors： Chen C,Li J,Zhou Z

更新日期：2004-05-01 00:00:00

abstract：:Clinical trials often use a binary "fold increase" endpoint defined according to the ratio of interval-censored measurement at end-of-study to that at baseline. We propose a simple yet principled analytic approach based on the linear mixed-effects model for interval-censored data for the analysis of such paired measur...

journal_title：Journal of biopharmaceutical statistics

authors： Xu Y,Lam KF,Ooi EE,Wilder-Smith A,Paton NI,Lee LS,Cheung YB

更新日期：2015-01-01 00:00:00

abstract：:For administrative convenience or cost efficiency, we may often employ a cluster randomized trial (CRT), in which randomized units are clusters of patients rather than individual patients. Furthermore, because of ethical reasons or patient's decision, it is not uncommon to encounter data in which there are patients no...

journal_title：Journal of biopharmaceutical statistics

authors： Lui KJ,Chang KC

更新日期：2011-01-01 00:00:00

abstract：:Classification measures play essential roles in the assessment and construction of classifiers. Hence, determining how to prevent these measures from being affected by individual observations has become an important problem. In this paper, we propose several indexes based on the influence function and the concept of l...

journal_title：Journal of biopharmaceutical statistics

authors： Ke BS,Chiang AJ,Chang YI

更新日期：2018-01-01 00:00:00

abstract：:A useful testing strategy is proposed for a confirmatory phase III clinical trial. It consists of a combined test of superiority and test of equivalence, and it is easy to apply. By introducing the strategy, we can perform a post hoc analysis in a confirmatory experiment. Thus a more flexible decision will be possible...

journal_title：Journal of biopharmaceutical statistics

authors： Morikawa T,Yoshida M

更新日期：1995-11-01 00:00:00

abstract：:According to ICH Q6A (1999), a specification is defined as a list of tests, references to analytical procedures, and appropriate acceptance criteria, which are numerical limits, ranges, or other criteria for the tests described. For drug products, specifications usually consist of test methods and acceptance criteria ...

journal_title：Journal of biopharmaceutical statistics

authors： Dong X,Tsong Y,Shen M

更新日期：2015-01-01 00:00:00

abstract：:In clinical trials, selection of appropriate study endpoints is critical for an accurate and reliable evaluation of safety and effectiveness of a test treatment under investigation. In practice, however, there are usually multiple endpoints available for measurement of disease status and/or therapeutic effect of the t...

journal_title：Journal of biopharmaceutical statistics

authors： Chow SC,Huang Z

更新日期：2019-01-01 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 the era of precision medicine, drugs are increasingly developed to target subgroups of patients with certain biomarkers. In large all-comer trials using a biomarker stratified design, the cost of treating and following patients for clinical outcomes may be prohibitive. With a fixed number of randomized patients, th...

journal_title：Journal of biopharmaceutical statistics

authors： Wang X,Zhou J,Wang T,George SL

更新日期：2018-01-01 00:00:00

abstract：:To confirm results obtained from local evaluation at investigational centers, many oncology studies utilize blinded independent central review (BICR) to make assessments of the primary endpoint, progression-free survival (PFS). The comparison of data often leads to large discordances between these observations, castin...

journal_title：Journal of biopharmaceutical statistics

authors： Mannino FV,Amit O,Lahiri S

更新日期：2013-01-01 00:00:00

abstract：:As more biologic products are going off patent protection, the development of follow-on biologic products (also known as biosimilars) has gained much attention from both the biotechnology industry and regulatory agencies. Unlike small molecules, the development of biologic products is not only more complicated but als...

journal_title：Journal of biopharmaceutical statistics

authors： Zhang N,Yang J,Chow SC,Chi E

更新日期：2014-01-01 00:00:00

abstract：:In randomized controlled trials, patients are recruited and randomly allocated to treatments. Patients are never randomly sampled from large population of patients on treatments under study. Therefore, it is important to consider the design and statistical analysis based on the randomization model. In this article, we...

journal_title：Journal of biopharmaceutical statistics

authors： Hasegawa T,Tango T

更新日期：2009-01-01 00:00:00

abstract：:The aim of this article is to propose a multilevel combined model for repeated, hierarchical, and overdispersed time-to-event outcomes, extending the so-called combined model proposed by Molenberghs et al. (2010), and using three different estimation strategies: full likelihood, pseudo-likelihood, and Bayesian estimat...

journal_title：Journal of biopharmaceutical statistics

authors： Efendi A,Molenberghs G

更新日期：2013-01-01 00:00:00

abstract：:ETRANK is a statistical software which uses nonparametric (randomization) technique to analyze incomplete repeated measures data, where the pattern of withdrawal is treatment related. This stand alone program is written in C, presently runs in MS-DOS, and a Windows version is in development. The program has been devel...

journal_title：Journal of biopharmaceutical statistics

authors： Entsuah R

更新日期：1996-11-01 00:00:00

abstract：:Rubinstein et al. presented a procedure for determining the required duration of accrual for a clinical trial comparing the survival distributions of two treatments using a classical hypothesis testing formulation. Here their testing procedure is modified in two ways. First, the asymptotic variances used in computatio...

journal_title：Journal of biopharmaceutical statistics

authors： Bristol DR

更新日期：1993-09-01 00:00:00

abstract：:For the assessment of biosimilarity of biosimilar products, the United States (US) Food and Drug Administration (FDA) proposed a stepwise approach for providing the totality-of-the-evidence of similarity between a proposed biosimilar product and a US-licensed (reference) product. The stepwise approach starts with the ...

journal_title：Journal of biopharmaceutical statistics

authors： Wang T,Chow SC

更新日期：2017-01-01 00:00:00

abstract：:Although asymptotically, the empirical covariance estimator is consistent and robust with respect to the selection of the working correlation matrix, when the sample size is small, its bias may not be negligible. This article proposes a small sample correction for the empirical covariance estimator in general Gaussian...

journal_title：Journal of biopharmaceutical statistics

authors： Fan C,Zhang D,Zhang CH

更新日期：2012-01-01 00:00:00

abstract：:We would like to estimate the parameters of a dose-response function with the greatest precision as possible. For a two-parameter model, this is equivalent to minimizing the area of the confidence ellipsoid, i.e., a D-optimal design. Previous work on this particular model has included minimal designs. These designs ar...

journal_title：Journal of biopharmaceutical statistics

authors： Lupinacci PJ,Raghavarao D

更新日期：2000-02-01 00:00:00

abstract：:The purpose of the research is to develop a statistical decision support algorithm for patients who may benefit from Adjuvant Cisplatin/Vinorelbine (ACT) and improve their survival rates. Genome-wide microarray data are used to identify feasible sets of genes and probe sets that constitute the gene signature. The data...

journal_title：Journal of biopharmaceutical statistics

authors： Moon H,Chao T,Ahn H

更新日期：2020-05-03 00:00:00

abstract：:We study the statistical efficiency for rising-dose designs in the context of first-in-human studies. Specifically, we identify a class of crossover designs that are appealing in terms of both subject safety and statistical efficiency and, for a three-period, two-panel design in such a class, we compare its A-efficien...

journal_title：Journal of biopharmaceutical statistics

authors： Yan Z,Hosmane B,Locke C

更新日期：2013-01-01 00:00:00

abstract：:Patient-reported outcomes are important for assessing the effectiveness of treatments in many disease areas. For this reason, many new instruments that capture patient-reported outcomes have been developed over the past several decades. With the development of each new instrument, there is the ensuing question of what...

journal_title：Journal of biopharmaceutical statistics

authors： Kirby S,Chuang-Stein C,Morris M

更新日期：2010-09-01 00:00:00

abstract：:One of the most critical decision points in clinical development is Go/No-Go decision-making after a proof-of-concept study. Traditional decision-making relies on a formal hypothesis testing with control of type I and type II error rates, which is limited by assessing the strength of efficacy evidence in a small isola...

journal_title：Journal of biopharmaceutical statistics

authors： Huang B,Talukder E,Han L,Kuan PF

更新日期：2019-01-01 00:00:00

abstract：:After a group sequential test, the naive confidence interval (CI) is usually biased in the sense that it does not cover the true parameter at the correct nominal level. Furthermore, when the stopping time is taken into account, the actual conditional confidence coverage probability can be much less accurate. In this a...

journal_title：Journal of biopharmaceutical statistics

authors： Fan X,DeMets DL

更新日期：2006-01-01 00:00:00

abstract：:Laboratory data with a lower quantification limit (censored data) are sometimes analyzed by replacing non-quantifiable values with a single value equal to or less than the quantification limit, yielding possibly biased point estimates and variance estimates that are too small. Motivated by a three-period, three-treatm...

journal_title：Journal of biopharmaceutical statistics

authors： Karon JM,Wiegand RE,van de Wijgert JH,Kilmarx PH

更新日期：2015-01-01 00:00:00

abstract：:We assess the QT effect using an exposure-response model in a "thorough QT/QTc study" with a four-period crossover design in which the treatments are placebo, positive control, higher dose of investigational drug, and therapeutic dose of investigational drug. In the study, QTc interval values and the drug concentratio...

journal_title：Journal of biopharmaceutical statistics

authors： Hosmane B,Locke C,Chiu YL

更新日期：2010-05-01 00:00:00

abstract：:For approval of generic drugs, the U.S. Food and Drug Administration (FDA) requires the evidence of bioequivalence in average bioavailability be provided. This is based on the Fundmental Bioequivalence Assumption from FDA that if two drug products are shown to be bioequivalent, it is assumed that they are therapeutica...

journal_title：Journal of biopharmaceutical statistics

authors： Lu Y,Zhang ZZ,Chow SC

更新日期：2014-01-01 00:00:00

abstract：:Due to the potential impact of ethnic factors on clinical outcomes, the global registration of a new treatment is challenging. China and Japan often require local trials in addition to a multiregional clinical trial (MRCT) to support the efficacy and safety claim of the treatment. The impact of ethnic factors on the t...

journal_title：Journal of biopharmaceutical statistics

authors： Huang Q,Chen G,Yuan Z,Lan KK

更新日期：2012-09-01 00:00:00