abstract：:In preclinical tumor xenograft experiments, the antitumor activity of the tested agents is often assessed by endpoints such as tumor doubling time, tumor growth delay (TGD), and log10 cell kill (LCK). In tumor xenograft literature, the values of these endpoints are presented without any statistical inference, which ig...

journal_title：Journal of biopharmaceutical statistics

authors： Wu J

更新日期：2011-05-01 00:00:00

abstract：:In many clinical trials for chronic conditions a run-in period is used prior to randomization. Often, only those participants who meet certain criteria during the run-in phase go on to get randomized. The others, along with the information that they might have provided, are excluded from the study. This exclusion of t...

journal_title：Journal of biopharmaceutical statistics

authors： Berger VW,Vali B

更新日期：2011-03-01 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：:The Log-odds ratio for 2 × 2 contingency tables is often approximated by a normal distribution with an approximated variance. Hwang and Biswas (2008) illustrated that the standard expression for the variance should be modified in the presence of correlation. They also provided an adjustment to this variance expression...

journal_title：Journal of biopharmaceutical statistics

authors： Biswas A,Hwang JS

更新日期：2011-01-01 00:00:00

abstract：:The Food and Drug Administration of the United States issued a draft guidance on adaptive design clinical trials in February 2010. This draft guidance has attracted a lot of attention because of the increasing interest in adaptive trials by the pharmaceutical industry in recent years. In this paper, we report on highl...

journal_title：Journal of biopharmaceutical statistics

authors： Chuang-Stein C,Beltangady M

更新日期：2010-11-01 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：: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：: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：:Drug-related side effects are one of the leading causes of death and illness in the developed world. Finding genes that modify drug response has the potential to significantly improve drug delivery, by identifying both individuals that can benefit from therapy and those at increased risk of harm. We present a simple a...

journal_title：Journal of biopharmaceutical statistics

authors： He M,Allen A

更新日期：2010-03-01 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：: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：:The adverse events data of randomized clinical trials are often analyzed based on either crude incidence rates or exposure-adjusted incidence rates. These rates do not adequately account for an individual patient's profile of adverse events over the study period when an individual may remain in the trial after experie...

journal_title：Journal of biopharmaceutical statistics

authors： Siddiqui O

更新日期：2009-09-01 00:00:00

abstract：:The study of drug combinations has become important in drug development due to its potential for efficacy at lower, less toxic doses and the need to move new therapies rapidly into clinical trials. The goal is to identify which combinations are additive, synergistic, or antagonistic. Although there exists statistical ...

journal_title：Journal of biopharmaceutical statistics

authors： Fang HB,Tian GL,Li W,Tan M

更新日期：2009-07-01 00:00:00

abstract：:Multiple testing problems in regulatory applications are often more challenging than the problems of handling a set of mathematical symbols representing multiple null hypotheses under testing. In the union-intersection setting, it is important to define a family of null hypotheses relevant to the clinical questions at...

journal_title：Journal of biopharmaceutical statistics

authors： Hung HM,Wang SJ

更新日期：2009-01-01 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：:In this paper I consider a problem of identifying all effective and superior drug combinations. I formulate this problem in terms of a family of hypotheses and propose a two-stage method to solve it. The first stage uses individual p-values obtained via the Min tests, whereas Holm's approach is employed in the second ...

journal_title：Journal of biopharmaceutical statistics

authors： Soulakova JN

更新日期：2009-01-01 00:00:00

abstract：:A new two-stage design is proposed that is suitable for early detection of the anticancer activity of experimental therapies in Phase II oncology trials. The endpoints of interest are response rate and early progression rate. The anticancer activity is defined by a positive signal in one endpoint and a non-negative si...

journal_title：Journal of biopharmaceutical statistics

authors： Sun LZ,Chen C,Patel K

更新日期：2009-01-01 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：:Gene expression profiling has played an important role in cancer risk classification and has shown promising results. Since gene expression profiling often involves determination of a set of top rank genes for analysis, it is important to evaluate how modeling performance varies with the number of selected top ranked ...

journal_title：Journal of biopharmaceutical statistics

authors： Chen DT,Schell MJ,Chen JJ,Fulp WJ,Eschrich S,Yeatman T

更新日期：2008-01-01 00:00:00

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：: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：:Highly clustered count data are commonly seen in medical device clinical studies such as cardiac rhythm management. For instance, anti-arrhythmia shocks delivered from an implantable cardioverter-defibrillator (ICD) often occur as "storms", i.e., multiple shocks within a short period of time. There are unique challeng...

journal_title：Journal of biopharmaceutical statistics

authors： Wang ZJ

更新日期：2008-01-01 00:00:00

abstract：:The ICH E14 guidance (ICH, 2005) recommend that a concurrent positive control should be included in a thorough QTc clinical trial to validate the study. The ICH E14 guidance (ICH, 2005) state that "The positive control should have an effect on the mean QTc interval of about 5 ms (i.e., an effect that is close to the Q...

journal_title：Journal of biopharmaceutical statistics

authors： Zhang J

更新日期：2008-01-01 00:00:00

abstract：:Receptor occupancy (RO) PET is a non-invasive way to determine drug on target. Given the complexity of procedures, long acquisition times, and high cost, ligand displacement imaging trials often have a limited size and produce sparse RO results over the time course of the blocking drug. To take the best advantage of t...

journal_title：Journal of biopharmaceutical statistics

authors： Vandenhende F,Renard D,Nie Y,Kumar A,Miller J,Tauscher J,Witcher J,Zhou Y,Wong DF

更新日期：2008-01-01 00:00:00

abstract：:The United States Pharmacopeia (USP) content uniformity sampling acceptance plan consisting of a two-stage sampling plan with criteria on sample mean and number of out-of-range tablets is the standard for compendium. It is, however, often used mistakenly for lot quality assurance. In comparison to the Japan Phamacopei...

journal_title：Journal of biopharmaceutical statistics

authors： Tsong Y,Shen M

更新日期：2007-01-01 00:00:00

abstract：:Bayesian decision procedures have already been proposed for and implemented in Phase I dose-escalation studies in healthy volunteers. The procedures have been based on pharmacokinetic responses reflecting the concentration of the drug in blood plasma and are conducted to learn about the dose-response relationship whil...

journal_title：Journal of biopharmaceutical statistics

authors： Whitehead J,Zhou Y,Hampson L,Ledent E,Pereira A

更新日期：2007-01-01 00:00:00

abstract：:Testing for noninferiority and equivalence between an experimental therapy and a standard therapy in terms of the ratio of binomial proportions is considered. New tests based on the Fieller-Hinkley distribution of the ratio of random variables are proposed. Restricted maximum likelihood estimates of the null variances...

journal_title：Journal of biopharmaceutical statistics

authors： Koti KM

更新日期：2007-01-01 00:00:00

abstract：:To ensure that a drug product will meet standards for identity, strength and stability as specified in the United States Pharmacopedia and National Formulary (USP/NF), it needs to pass a number of tests such as the content uniformity test and dissolution test at various stages of the manufacturing process. The sponsor...

journal_title：Journal of biopharmaceutical statistics

authors： Wang H

更新日期：2007-01-01 00:00:00

abstract：:In method comparison and reliability studies, it is often important to assess agreement between multiple measurements made by different methods, devices, laboratories, observers, or instruments. For continuous data, the concordance correlation coefficient (CCC) is a popular index for assessing agreement between multip...

journal_title：Journal of biopharmaceutical statistics

authors： Barnhart HX,Lokhnygina Y,Kosinski AS,Haber M

更新日期：2007-01-01 00:00:00

abstract：:We studied the sensitivity of the number of unique design points and their placement, in Bayesian optimal designs for pharmacokinetic models, with respect to the magnitude of prior uncertainty. We used two and three-parameter pharmacokinetic models with fixed and mixed effects and two Bayesian optimal design criteria,...

journal_title：Journal of biopharmaceutical statistics

authors： Dokoumetzidis A,Aarons L

更新日期：2007-01-01 00:00:00

abstract：:A randomized, active-control clinical trial setting with the objective of testing noninferiority for a continuous response variable is considered. Noninferiority margin is based on the concept of preserving a certain fraction of the active control effect. Noninferiority is established if the ratio of the lower (upper)...

journal_title：Journal of biopharmaceutical statistics

authors： Chen M,Kianifard F,Dhar SK

更新日期：2006-05-01 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：:The van Elteren test, as a type of stratified Wilcoxon-Mann-Whitney test for comparing two treatments accounting for stratum effects, has been used to replace the analysis of variance when the normality assumption was seriously violated. The sample size estimation methods for the van Elteren test have been proposed an...

journal_title：Journal of biopharmaceutical statistics

authors： Zhao YD,Qu Y,Rahardja D

更新日期：2006-01-01 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：:Rank-based test procedures in censored survival data differ considerably in their sensitivity to various alternatives to the hypothesis of equality of underlying distributions. Procedures based on the simultaneous use of multiple statistics provide an appealing approach to obtaining more global sensitivity while maint...

journal_title：Journal of biopharmaceutical statistics

authors： Yang P,Fleming TR

更新日期：2006-01-01 00:00:00

abstract：:I review the designs available for Phase I dose-finding studies of chemotherapeutic agents in cancer patients. The designs are based on the assumption that both efficacy and toxicity increase with dose, and thus attempt to minimize the number of patients treated at low doses, and also to minimize the chance that patie...

journal_title：Journal of biopharmaceutical statistics

authors： Potter DM

更新日期：2006-01-01 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：:In various pharmaceutical applications, repeated measurements are taken from each subject, and model parameters are estimated from the collected data. Examples include dose response modeling and PK/PD studies with serial blood sampling, among others. The quality of the information in an experiment is reflected in the ...

journal_title：Journal of biopharmaceutical statistics

authors： Gagnon R,Leonov S

更新日期：2005-01-01 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：:There are minimal standards for the processing of whole blood components, and to apply those standards requires a system of quality assurances. Excessive indications of failures in compliance trigger inspections and other remedial actions, but the demarcation of what is excessive is a critical issue. Issues of low vol...

journal_title：Journal of biopharmaceutical statistics

authors： Lachenbruch PA,Foulkes MA,Williams AE,Epstein JS

更新日期：2005-01-01 00:00:00