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1.
Pharm Stat ; 21(4): 720-728, 2022 07.
Article in English | MEDLINE | ID: mdl-35819119

ABSTRACT

The Acute Stroke Therapy by Inhibition of Neutrophils (ASTIN) study, initiated in November of the year 2000, is now widely recognized as having been a landmark study in the history of clinical trials. We look at why this is the case by considering its key features and impact. These key features are: the use of Bayesian design and analysis; the use of the normal dynamic linear model; the response adaptive nature of the study; the use of real-time dosing decisions; and the use of an integrated model to predict 90-day response on the Scandinavian Stroke Scale. Our overall conclusion is that the ASTIN study's main impact came from showing the clinical trial community the feasibility of the novel design and analysis used when most of these key features were rarely used in industry trials, let alone used together in one trial in a disease area with a tremendous unmet medical need.


Subject(s)
Neutrophils , Stroke , Bayes Theorem , Humans , Linear Models , Stroke/drug therapy
2.
Ann Intern Med ; 172(2): 119-125, 2020 01 21.
Article in English | MEDLINE | ID: mdl-31739312

ABSTRACT

Data monitoring committees (DMCs), or data and safety monitoring boards, protect clinical trial participants by conducting benefit-risk assessments during the course of a clinical trial. These evaluations may be improved by broader access to data and more effective analyses and presentation. Data monitoring committees should have access to all data, including efficacy data, at each interim review. The DMC reports should include graphical presentations that summarize benefits and harms in efficient ways. Benefit-risk assessments should include summaries that are consistent with the intention-to-treat principle and have a pragmatic focus. This article provides examples of graphical summaries that integrate benefits and harms, and proposes that such summaries become standard in DMC reports.


Subject(s)
Clinical Trials Data Monitoring Committees , Quality Improvement , Access to Information , Data Interpretation, Statistical , Decision Making , Humans , Risk Assessment
3.
Pharm Stat ; 18(1): 65-77, 2019 01.
Article in English | MEDLINE | ID: mdl-30362223

ABSTRACT

Networks of constellations of longitudinal observational databases, often electronic medical records or transactional insurance claims or both, are increasingly being used for studying the effects of medicinal products in real-world use. Such databases are frequently configured as distributed networks. That is, patient-level data are kept behind firewalls and not communicated outside of the data vendor other than in aggregate form. Instead, data are standardized across the network, and queries of the network are executed locally by data partners, and summary results provided to a central research partner(s) for amalgamation, aggregation, and summarization. Such networks can be huge covering years of data on upwards of 100 million patients. Examples of such networks include the FDA Sentinel Network, ASPEN, CNODES, and EU-ADR. As this is a new emerging field, we note in this paper the conceptual similarities and differences between the analysis of distributed networks and the now well-established field of meta-analysis of randomized clinical trials (RCTs). We recommend, wherever appropriate, to apply learnings from meta-analysis to help guide the development of distributed network analyses of longitudinal observational databases.


Subject(s)
Computer Communication Networks/statistics & numerical data , Data Mining/statistics & numerical data , Databases, Factual/statistics & numerical data , Meta-Analysis as Topic , Observational Studies as Topic/statistics & numerical data , Randomized Controlled Trials as Topic/statistics & numerical data , Research Design/statistics & numerical data , Adverse Drug Reaction Reporting Systems/statistics & numerical data , Angioedema/chemically induced , Angioedema/diagnosis , Angioedema/epidemiology , Angiotensin-Converting Enzyme Inhibitors/adverse effects , Data Accuracy , Data Interpretation, Statistical , Data Mining/methods , Humans , Observational Studies as Topic/methods , Randomized Controlled Trials as Topic/methods , Risk Assessment , Risk Factors
4.
Stat Med ; 36(28): 4427-4436, 2017 Dec 10.
Article in English | MEDLINE | ID: mdl-28722159

ABSTRACT

The Food and Drug Administration in the United States issued a much-awaited draft guidance on 'Multiple Endpoints in Clinical Trials' in January 2017. The draft guidance is well written and contains consistent message on the technical implementation of the principles laid out in the guidance. In this commentary, we raise a question on applying the principles to studies designed from a safety perspective. We then direct our attention to issues related to multiple co-primary endpoints. In a paper published in the Drug Information Journal in 2007, Offen et al. give examples of disorders where multiple co-primary endpoints are required by regulators. The standard test for multiple co-primary endpoints is the min test which tests each endpoint individually, at the one-sided 2.5% level, for a confirmatory trial. This approach leads to a substantial loss of power when the number of co-primary endpoints exceeds 2, a fact acknowledged in the draft guidance. We review approaches that have been proposed to tackle the problem of power loss and propose a new one. Using recommendations by Chen et al. for the assessment of drugs for vulvar and vaginal atrophy published in the Drug Information Journal in 2010, we argue the need for more changes and urge a path forward that uses different levels of claims to reflect the effectiveness of a product on multiple endpoints that are equally important and mostly unrelated. Copyright © 2017 John Wiley & Sons, Ltd.


Subject(s)
Endpoint Determination/methods , Pharmaceutical Preparations , Research Design , Atrophy/drug therapy , Bias , Female , Guidelines as Topic , Humans , Limit of Detection , Pharmaceutical Preparations/standards , Sample Size , United States , United States Food and Drug Administration , Vagina/pathology , Vulva/pathology
5.
JMIR Mhealth Uhealth ; 5(2): e18, 2017 Feb 21.
Article in English | MEDLINE | ID: mdl-28223265

ABSTRACT

BACKGROUND: Accurately monitoring and collecting drug adherence data can allow for better understanding and interpretation of the outcomes of clinical trials. Most clinical trials use a combination of pill counts and self-reported data to measure drug adherence, despite the drawbacks of relying on these types of indirect measures. It is assumed that doses are taken, but the exact timing of these events is often incomplete and imprecise. OBJECTIVE: The objective of this pilot study was to evaluate the use of a novel artificial intelligence (AI) platform (AiCure) on mobile devices for measuring medication adherence, compared with modified directly observed therapy (mDOT) in a substudy of a Phase 2 trial of the α7 nicotinic receptor agonist (ABT-126) in subjects with schizophrenia. METHODS: AI platform generated adherence measures were compared with adherence inferred from drug concentration measurements. RESULTS: The mean cumulative pharmacokinetic adherence over 24 weeks was 89.7% (standard deviation [SD] 24.92) for subjects receiving ABT-126 who were monitored using the AI platform, compared with 71.9% (SD 39.81) for subjects receiving ABT-126 who were monitored by mDOT. The difference was 17.9% (95% CI -2 to 37.7; P=.08). CONCLUSIONS: Using drug levels, this substudy demonstrates the potential of AI platforms to increase adherence, rapidly detect nonadherence, and predict future nonadherence. Subjects monitored using the AI platform demonstrated a percentage change in adherence of 25% over the mDOT group. Subjects were able to use the technology successfully for up to 6 months in an ambulatory setting with early termination rates that are comparable to subjects outside of the substudy. TRIAL REGISTRATION: ClinicalTrials.gov NCT01655680 https://clinicaltrials.gov/ct2/show/NCT01655680?term=NCT01655680.

6.
Pharm Stat ; 16(1): 37-44, 2017 01.
Article in English | MEDLINE | ID: mdl-27678332

ABSTRACT

The first trial of clinical efficacy is an important step in the development of a compound. Such a trial gives the first indication of whether a compound is likely to have the efficacy needed to be successful. Good decisions dictate that good compounds have a large probability of being progressed and poor compounds have a large probability of being stopped. In this paper, we consider and contrast five approaches to decision-making that have been used. To illustrate the use of the five approaches, we conduct a comparison for two plausible scenarios with associated assumptions for sample sizing. The comparison shows some large differences in performance characteristics of the different procedures. Which decision-making procedures and associated performance characteristics are preferred will depend on the focus of interest and the decision maker's attitude to risk. Copyright © 2016 John Wiley & Sons, Ltd.


Subject(s)
Clinical Trials as Topic/methods , Decision Making , Research Design , Data Interpretation, Statistical , Drug Design , Humans , Models, Statistical , Risk , Sample Size
7.
Biom J ; 58(1): 76-88, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26332597

ABSTRACT

In 2010, the Federal Parliament (Bundestag) of Germany passed a new law (Arzneimittelmarktneuordnungsgesetz, AMNOG) on the regulation of medicinal products that applies to all pharmaceutical products with active ingredients that are launched beginning January 1, 2011. The law describes the process to determine the price at which an approved new product will be reimbursed by the statutory health insurance system. The process consists of two phases. The first phase assesses the additional benefit of the new product versus an appropriate comparator (zweckmäßige Vergleichstherapie, zVT). The second phase involves price negotiation. Focusing on the first phase, this paper investigates requirements of benefit assessment of a new product under this law with special attention on the methods applied by the German authorities on issues such as the choice of the comparator, patient relevant endpoints, subgroup analyses, extent of benefit, determination of net benefit, primary and secondary endpoints, and uncertainty of the additional benefit. We propose alternative approaches to address the requirements in some cases and invite other researchers to help develop solutions in other cases.


Subject(s)
Clinical Trials, Phase III as Topic/legislation & jurisprudence , Drug Industry/legislation & jurisprudence , Government Regulation , Endpoint Determination , Humans
8.
Ther Innov Regul Sci ; 50(4): 455-463, 2016 Jul.
Article in English | MEDLINE | ID: mdl-30227021

ABSTRACT

Product labels are intended to provide health care professionals with clear and concise prescribing information that will enhance the safe and effective use of drug products. In this manuscript, we offer suggestions to improve product labels. First, we recommend that product labels that include comparator data be changed to include adjusted incidence proportions (or adjusted incidence rates when needed and appropriate) for adverse drug reactions that are somewhat common. Second, we believe that including comparator incidence in product labels is a good practice, as it gives health care providers and patients appropriate information to put the absolute risks in perspective. Finally, we recommend changing the practice of reporting extremely rare events based on the "Rule of 3" in the Summary of Product Characteristics in Europe. We recommend that these adverse drug reactions be put in a separate table from other adverse drug reactions with a note that it is difficult to reliably estimate their incidences. In exceptional circumstances, it may be possible to present an estimate of their incidence based on postmarketing data. We believe the proposed changes could help product labels to better reflect the risk of a drug relative to a comparator.

9.
Stat Biopharm Res ; 7(3): 174-190, 2015 Jul 03.
Article in English | MEDLINE | ID: mdl-26550466

ABSTRACT

In March 2011, a Final Rule for expedited reporting of serious adverse events took effect in the United States for studies conducted under an Investigational New Drug (IND) application. In December 2012, the U.S. Food and Drug Administration (FDA) promulgated a final Guidance describing the operationalization of this Final Rule. The Rule and Guidance clarified that a clinical trial sponsor should have evidence suggesting causality before defining an unexpected serious adverse event as a suspected adverse reaction that would require expedited reporting to the FDA. The Rule's emphasis on the need for evidence suggestive of a causal relation should lead to fewer events being reported but, among those reported, a higher percentage actually being caused by the product being tested. This article reviews the practices that were common before the Final Rule was issued and the approach the New Rule specifies. It then discusses methods for operationalizing the Final Rule with particular focus on relevant statistical considerations. It concludes with a set of recommendations addressed to Sponsors and to the FDA in implementing the Final Rule.

10.
Clin Infect Dis ; 61(5): 800-6, 2015 Sep 01.
Article in English | MEDLINE | ID: mdl-26113652

ABSTRACT

Clinical trials that compare strategies to optimize antibiotic use are of critical importance but are limited by competing risks that distort outcome interpretation, complexities of noninferiority trials, large sample sizes, and inadequate evaluation of benefits and harms at the patient level. The Antibacterial Resistance Leadership Group strives to overcome these challenges through innovative trial design. Response adjusted for duration of antibiotic risk (RADAR) is a novel methodology utilizing a superiority design and a 2-step process: (1) categorizing patients into an overall clinical outcome (based on benefits and harms), and (2) ranking patients with respect to a desirability of outcome ranking (DOOR). DOORs are constructed by assigning higher ranks to patients with (1) better overall clinical outcomes and (2) shorter durations of antibiotic use for similar overall clinical outcomes. DOOR distributions are compared between antibiotic use strategies. The probability that a randomly selected patient will have a better DOOR if assigned to the new strategy is estimated. DOOR/RADAR represents a new paradigm in assessing the risks and benefits of new strategies to optimize antibiotic use.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Clinical Trials as Topic , Drug Resistance, Bacterial , Research Design , Bacterial Infections/drug therapy , Humans , Patient Safety , Risk , Treatment Outcome
12.
Pharm Stat ; 13(5): 277-80, 2014.
Article in English | MEDLINE | ID: mdl-25182453

ABSTRACT

It is frequently noted that an initial clinical trial finding was not reproduced in a later trial. This is often met with some surprise. Yet, there is a relatively straightforward reason partially responsible for this observation. In this article, we examine this reason by first reviewing some findings in a recent publication in the Journal of the American Medical Association. To help explain the non-negligible chance of failing to reproduce a previous positive finding, we compare a series of trials to successive diagnostic tests used for identifying a condition. To help explain the suspicion that the treatment effect, when observed in a subsequent trial, seems to have decreased in magnitude, we draw a conceptual analogy between phases II-III development stages and interim analyses of a trial with a group sequential design. Both analogies remind us that what we observed in an early trial could be a false positive or a random high. We discuss statistical sources for these occurrences and discuss why it is important for statisticians to take these into consideration when designing and interpreting trial results.


Subject(s)
Clinical Trials as Topic/standards , Empirical Research , Treatment Outcome , Clinical Trials as Topic/methods , Humans
14.
Pharm Stat ; 13(4): 265-74, 2014.
Article in English | MEDLINE | ID: mdl-24931490

ABSTRACT

'Success' in drug development is bringing to patients a new medicine that has an acceptable benefit-risk profile and that is also cost-effective. Cost-effectiveness means that the incremental clinical benefit is deemed worth paying for by a healthcare system, and it has an important role in enabling manufacturers to obtain new medicines to patients as soon as possible following regulatory approval. Subgroup analyses are increasingly being utilised by decision-makers in the determination of the cost-effectiveness of new medicines when making recommendations. This paper highlights the statistical considerations when using subgroup analyses to support cost-effectiveness for a health technology assessment. The key principles recommended for subgroup analyses supporting clinical effectiveness published by Paget et al. are evaluated with respect to subgroup analyses supporting cost-effectiveness. A health technology assessment case study is included to highlight the importance of subgroup analyses when incorporated into cost-effectiveness analyses. In summary, we recommend planning subgroup analyses for cost-effectiveness analyses early in the drug development process and adhering to good statistical principles when using subgroup analyses in this context. In particular, we consider it important to provide transparency in how subgroups are defined, be able to demonstrate the robustness of the subgroup results and be able to quantify the uncertainty in the subgroup analyses of cost-effectiveness.


Subject(s)
Cost-Benefit Analysis/methods , Technology Assessment, Biomedical , Humans , Technology Assessment, Biomedical/economics , Uncertainty
15.
Ther Innov Regul Sci ; 48(3): 316-326, 2014 May.
Article in English | MEDLINE | ID: mdl-30235541

ABSTRACT

Adaptive clinical trials require access to interim data to carry out trial modification as allowed by a prespecified adaptation plan. A data monitoring committee (DMC) is a group of experts that is charged with monitoring accruing trial data to ensure the safety of trial participants and that in adaptive trials may also play a role in implementing a preplanned adaptation. In this paper, we summarize current practices and viewpoints and provide guidance on evolving issues related to the use of DMCs in adaptive trials. We describe the common types of adaptive designs and point out some DMC-related issues that are unique to this class of designs. We include 3 examples of DMCs in late-stage adaptive trials that have been implemented in practice. We advocate training opportunities for researchers who may be interested in serving on a DMC for an adaptive trial since qualified DMC members are fundamental to the successful execution of DMC responsibilities.

17.
J Biopharm Stat ; 23(1): 3-25, 2013.
Article in English | MEDLINE | ID: mdl-23331218

ABSTRACT

The last 15 years have seen a substantial increase in efforts devoted to safety assessment by statisticians in the pharmaceutical industry. While some of these efforts were driven by regulations and public demand for safer products, much of the motivation came from the realization that there is a strong need for a systematic approach to safety planning, evaluation, and reporting at the program level throughout the drug development life cycle. An efficient process can help us identify safety signals early and afford us the opportunity to develop effective risk minimization plan early in the development cycle. This awareness has led many pharmaceutical sponsors to set up internal systems and structures to effectively conduct safety assessment at all levels (patient, study, and program). In addition to process, tools have emerged that are designed to enhance data review and pattern recognition. In this paper, we describe advancements in the practice of safety assessment during the premarketing phase of drug development. In particular, we share examples of safety assessment practice at our respective companies, some of which are based on recommendations from industry-initiated working groups on best practice in recent years.


Subject(s)
Drug Discovery/standards , Drug Industry/standards , Patient Safety/standards , Pharmaceutical Preparations/standards , Clinical Trials as Topic/economics , Clinical Trials as Topic/standards , Drug Discovery/economics , Drug Industry/economics , Humans , Marketing , Patient Safety/economics , Pharmaceutical Preparations/economics
18.
Ther Innov Regul Sci ; 47(4): 495-502, 2013 Jul.
Article in English | MEDLINE | ID: mdl-30235521

ABSTRACT

In this paper, the authors express their views on a range of topics related to data monitoring committees (DMCs) for adaptive trials that have emerged recently. The topics pertain to DMC roles and responsibilities, membership, training, and communication. DMCs have been monitoring trials using the group sequential design (GSD) for over 30 years. While decisions may be more complicated with novel adaptive designs, the fundamental roles and responsibilities of a DMC will remain the same, namely, to protect patient safety and ensure the scientific integrity of the trial. It will be the DMC's responsibility to recommend changes to the trial within the scope of a prespecified adaptation plan or decision criteria and not to otherwise recommend changes to the study design except for serious safety-related concerns. Nevertheless, compared with traditional data monitoring, some additional considerations are necessary when convening DMCs for novel adaptive designs. They include the need to identify DMC members who are familiar with adaptive design and to consider possible sponsor involvement in unique situations. The need for additional expertise in DMC members has prompted some researchers to propose alternative DMC models or alternative governance model. These various options and authors' views on them are expressed in this article.

19.
J Biopharm Stat ; 22(6): 1097-108, 2012.
Article in English | MEDLINE | ID: mdl-23075010

ABSTRACT

We introduce the idea of a design to detect signals of efficacy in early phase clinical trials. Such a design features three possible decisions: to kill the compound; to continue with staged development; or to continue with accelerated development of the compound. We describe how such studies improve the trade-off between the two errors of killing a compound with good efficacy and committing to a complete full development program for a compound that has no efficacy and describe how they can be designed. We argue that such studies could be used to screen compounds at the proof-of-concept state, reduce late Phase 2 attrition, and speed up the development of highly efficacious drugs.


Subject(s)
Clinical Trials as Topic/statistics & numerical data , Drug Design , Research Design/statistics & numerical data , Treatment Outcome , Clinical Trials as Topic/methods , Humans , Models, Statistical , Research Design/trends
20.
Pharm Stat ; 10(6): 532-8, 2011.
Article in English | MEDLINE | ID: mdl-22140066

ABSTRACT

Subgroup analysis is an integral part of access and reimbursement dossiers, in particular health technology assessment (HTA), and their HTA recommendations are often limited to subpopulations. HTA recommendations for subpopulations are not always clear and without controversies. In this paper, we review several HTA guidelines regarding subgroup analyses. We describe good statistical principles for subgroup analyses of clinical effectiveness to support HTAs and include case examples where HTA recommendations were given to subpopulations only. Unlike regulatory submissions, pharmaceutical statisticians in most companies have had limited involvement in the planning, design and preparation of HTA/payers submissions. We hope to change this by highlighting how pharmaceutical statisticians should contribute to payers' submissions. This includes early engagement in reimbursement strategy discussions to influence the design, analysis and interpretation of phase III randomized clinical trials as well as meta-analyses/network meta-analyses. The focus on this paper is on subgroup analyses relating to clinical effectiveness as we believe this is the first key step of statistical involvement and influence in the preparation of HTA and reimbursement submissions.


Subject(s)
Randomized Controlled Trials as Topic/statistics & numerical data , Technology Assessment, Biomedical/statistics & numerical data , Guidelines as Topic , Humans
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