Statistical considerations for rare diseases drug development

ABSTRACT

One of the most challenges for rare disease clinical trials is probably the availability of a small patient population. It is then a great concern on how to conduct clinical trials with a small number of subjects available for obtaining substantial evidence regarding safety and effectiveness for approval of the rare disease drug product under investigation. FDA, however, does not have the intention to create a statutory standard for approval of orphan drugs that are different from the standard for approval of drugs in common conditions. Thus, it is suggested that innovative trial designs such as a complete n-of-1 trial design or an adaptive design should be used for an accurate and reliable assessment of rare disease drug products under investigation. In this article, basic considerations, innovative trial designs, and statistical methods for data analysis are discussed. In addition, some innovative thinking for the evaluation of rare disease drug products is proposed.     

Phase II cancer clinical trials for biomarker-guided treatments

ABSTRACT

The design and analysis of cancer clinical trials with biomarker depend on various factors, such as the phase of trials, the type of biomarker, whether the used biomarker is validated or not, and the study objectives. In this article, we demonstrate the design and analysis of two Phase II cancer clinical trials, one with a predictive biomarker and the other with an imaging prognostic biomarker. Statistical testing methods and their sample size calculation methods are presented for each trial. We assume that the primary endpoint of these trials is a time to event variable, but this concept can be used for any type of endpoint.     

有效应对流行病的新型临床试验设计

对于迅速演变的流行病来说,仅开展传统临床试验还是不能及时得到有意义的研究结果。在未来更好地应对流行病暴发,可能需要接受一种灵活的试验设计,这种设计可以绕过、加速或重新安排传统的3个临床研究阶段,同时又遵循候选药物安全性和有效性相关的科学规律。介绍了治疗新型冠状病毒肺炎（COVID-19）的8个适应性临床试验,及1个平台试验,同时还列举了2个疫苗研发的由真实世界证据（RWE）和随机对照试验（RCT）组成的混合设计方案。为了有效应对流行病,鼓励新型的临床试验设计,鼓励疫苗开发的新型研究策略。建议为未来可能发生的流行病制定药物研发计划,以进行适应性的、持续的、多地区的临床研究。     

Methodological issues associated with clinical trials in epilepsy

Introduction: despite methodological advances in epilepsy clinical trials, the proportion of patients reaching seizure-freedom has not substantially changed over the years. We review the main methodological limitations of current trials, the possible strategies to overcome these limits, and the issues that need to be addressed in next future.

Area covered: references were identified by PubMed search until March 2017 and unpublished literature was searched on ClinicalTrials.gov. Add-on trials mainly involve refractory epilepsy subjects, reducing overall response to the investigational drug. The inclusion of subjects with earlier disease from less developed countries has partially allowed overcoming this limitation, but has introduced more random variability of results. Monotherapy trials rise methodological, economical, and ethical concerns with different regulatory requirements in European Union and in the United States of America. Newer trial designs, such as futility trials or ‘time-to-event’ design, have been implemented. Moreover, both add-on and monotherapy trials results might be affected by patient’s ability to recognize and record seizures, and by randomness of seizures occurrence over time. Possible strategies to achieve more reliable outcomes are detailed.

Expert commentary: clinical trial methodology needs to be optimized to better address regulatory agencies requirements and to encounter both patients’ and clinicians’ needs.     

Tradeoff-based optimization criteria in clinical trials with multiple objectives and adaptive designs

ABSTRACT

The article discusses clinical trial optimization problems in the context of mid- to late-stage drug development. Using the Clinical Scenario Evaluation approach, main objectives of clinical trial optimization are formulated, including selection of clinically relevant optimization criteria, identification of sets of optimal and nearly optimal values of the parameters of interest, and sensitivity assessments. The paper focuses on a class of optimization criteria arising in clinical trials with several competing goals, termed tradeoff-based optimization criteria, and discusses key considerations in constructing and applying tradeoff-based criteria. The clinical trial optimization framework considered in the paper is illustrated using two case studies based on a clinical trial with multiple objectives and a two-stage clinical trial which utilizes adaptive decision rules.     

Methods for identification and confirmation of targeted subgroups in clinical trials: A systematic review

ABSTRACT

Important objectives in the development of stratified medicines include the identification and confirmation of subgroups of patients with a beneficial treatment effect and a positive benefit-risk balance. We report the results of a literature review on methodological approaches to the design and analysis of clinical trials investigating a potential heterogeneity of treatment effects across subgroups. The identified approaches are classified based on certain characteristics of the proposed trial designs and analysis methods. We distinguish between exploratory and confirmatory subgroup analysis, frequentist, Bayesian and decision-theoretic approaches and, last, fixed-sample, group-sequential, and adaptive designs and illustrate the available trial designs and analysis strategies with published case studies.     

Clinical trial design for unmet clinical needs: a spotlight on sepsis

ABSTRACT

Introduction: Despite considerable advances in our understanding of how sepsis develops and multiple clinical trials of potential therapies, no new pharmacologic agent has been consistently shown to improve survival.

Areas covered: We reviewed relevant publications identified through PubMed and from the authors’ knowledge of this field. We discuss the main reasons why clinical trials on new therapeutic interventions have failed in the past, including heterogeneity of study populations and choice of outcome measures. We discuss how changes in study design and in patient selection could help improve identification of effective agents in the future.

Expert opinion: The search for new sepsis therapies must continue but lessons must be learned from previous clinical trials so that the same mistakes are not repeated. Rather than grouping all patients with sepsis together, we should study only those most likely to benefit from the intervention. Better characterization of patients will be facilitated using modern ’omics technology and analysis of the increasingly large quantities of clinical data available, enabling more personalized patient selection for trial inclusion. New clinical trial design and inclusion of other endpoints in addition to mortality will also aid our search for the elusive positive clinical trial and effective interventions for sepsis.     

The failure of anxiolytic therapies in early clinical trials: what needs to be done

Introduction: Anxiety spectrum disorders (ASDs) are highly prevalent psychiatric illnesses that affect millions of people worldwide. Strongly associated with stress, common ASDs include generalized anxiety disorder, panic, social anxiety, phobias and drug-abuse-related anxiety. In addition to ASDs, several other prevalent psychiatric illnesses represent trauma/stressor-related disorders, such as post-traumatic stress disorder and acute stress disorder. Anxiolytic drugs, commonly prescribed to treat ASDs and trauma/stressor-related disorders, form a highly heterogenous group, modulating multiple neurotransmitters and physiological mechanisms. However, overt individual differences in efficacy and the potential for serious side-effects (including addiction and drug interaction) indicate a need for further drug development. Yet, over the past 50 years, there has been relatively little progress in the development of novel anxiolytic medications, especially when promising candidate drugs often fail in early clinical trials.

Areas covered: Herein, the authors present recommendations of the Task Force on Anxiolytic Drugs of the International Stress and Behavior Society on how to improve anxiolytic drug discovery. These recommendations cover a wide spectrum of aspects, ranging from methodological improvements to conceptual insights and innovation.

Expert opinion: In order to improve the success of anxiolytic drugs in early clinical trials, the goals of preclinical trials may need to be adjusted from a clinical perspective and better synchronized with those of clinical studies. Indeed, it is important to realize that the strategic goals and approaches must be similar if we want to have a smoother transition between phases.     

Interpreting the Regulatory Perspective on Adaptive Designs

The Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) and Center for Biologics Evaluation and Research (CBER) released a draft guidance (DG) on adaptive clinical trials (ACT) for drugs and biologics in February, 2010. In May, 2016, FDA Center for Devices and Radiological Heath (CDRH) and CBER issued the final guidance (FG) on adaptive medical device trials. The purpose of the FG is to provide clarity on how to plan and implement adaptive designs (AD) for clinical studies used in medical device development and to further encourage companies to use AD.

While both the device FG and drug and biologics DG provided positive review of ACT, the FG position was stronger, stating that the FDA centers “further encourage companies to consider the use of AD in their clinical trials.” Both guidances emphasize the importance of preplanning to avoid Type I error inflation, strict following of the plan to minimize operational bias, and frequent and early interactions with the FDA to ensure the success of the planned ACT. Both guidances emphasize the utilities of clinical trial simulations in design of ACT and in analysis of adaptive trial data. In this article, we present our understanding the guidances.     

浅谈医院药物临床试验的质量管理

摘 要药物临床试验是新药研发的一个重要环节。本文在强调落实《药物临床试验质量管理规范》（GCP）的同时,结合医院药物临床试验机构的工作现状,针对在药物临床试验项目全程中存在的申办方资质不全、研究者能力和态度欠缺、药物临床试验机构监管不到位及伦理委员审查不全面的突出问题,进行分析并提出整改意见,旨在提高药物临床试验的质控管理水平和药物临床试验的质量。     

Reflections on the adaptive designs accelerating promising trials into treatments (ADAPT-IT) process—Findings from a qualitative study

Abstract

The context for this study was the Adaptive Designs Advancing Promising Treatments Into Trials (ADAPT-IT) project, which aimed to incorporate flexible adaptive designs into pivotal clinical trials and to conduct an assessment of the trial development process. Little research provides guidance to academic institutions in planning adaptive trials. The purpose of this qualitative study was to explore the perspectives and experiences of stakeholders as they reflected back about the interactive ADAPT-IT adaptive design development process, and to understand their perspectives regarding lessons learned about the design of the trials and trial development. The authors conducted semi-structured interviews with 10 key stakeholders, and observations of the process. They employed qualitative thematic text data analysis to reduce the data into themes about the ADAPT-IT project and adaptive clinical trials. The qualitative analysis revealed four themes: education of the project participants, how the process evolved with participant feedback, procedures that could enhance the development of other trials, and education of the broader research community. While participants became more likely to consider flexible adaptive designs, additional education is needed to both understand the adaptive methodology and articulate it when planning trials.     

A Clinical Trial Design With Covariate-Adjusted Response-Adaptive Randomization Using Superiority Confidence of Treatments

Abstract

Adaptive randomization using response outcome or covariate is commonly used in the literature. However, the performance of these designs has not been thoroughly studied, especially when there are various interactions between the covariate and treatment. We have conducted simulations to evaluate the performance of commonly used designs under two-arm and multiple-arm situations. When a predictive factor exists, in the phase II trial conduction using adaptive designs, such as the BATTLE-1, BATTLE-2 trial, and ISPY-2 trials, researchers evaluate the operating characteristics using the traditional power assessment. In this article, new criteria are used in a general modeling frame work to incorporate the complicated interaction. Based on our evaluation, the covariate-adjusted and response-adaptive randomization (Sc-ca) results in a greater total number of responders. Additionally, the design can detect the treatment effect difference in subgroups, and consistently assign patients to the most beneficial treatment according to their covariate profiles. This translates into a higher proportion of individuals receiving optimized treatments compared with other commonly used designs. This adaptive design is a step toward personalized therapy to benefit each patient enrolled in a prospective clinical trial, when there is the strong evidence that predictive factors exist.     

Current and emerging treatment options in the management of advanced ovarian cancer

Introduction: Epithelial ovarian cancer is the most lethal gynecologic malignancy. Recent advances in understanding the biology and its molecular and histological diversity have led to mechanism based therapeutic strategies such as poly-ADP-ribose polymerase inhibitors (PARP) targeting homologous recombination deficient tumor cells and anti-angiogenic therapies. Clinical trial designs in ovarian cancer have to evolve to incorporate assessment of the genomic complexity and identify predictive biomarkers to improve precision of treatment and outcome.

Areas covered: This review summarizes present-day strategies used in the management of ovarian cancer and novel promising therapeutic approaches in development. The article is based on English peer-reviewed articles located on MEDLINE and related abstracts presented at major international meetings.

Expert opinion: Two types of molecular targeted therapies, anti-angiogenics and PARP inhibitors, have been shown to be active in randomized clinical trials and approved by regulatory agencies. Management of ovarian cancer is poised to change with the continued advancement of precision medicine that is founded upon improved understanding of disease biology; separation into histologically and molecularly defined subgroups; and the incorporation of this new knowledge into early phase drug development and novel clinical trial design.     

Factors to consider when selecting a nebulizer for a new inhaled drug product development program

Introduction: Nebulizers are a common device choice for use when developing a new drug product, but the range of nebulizer devices available can make it difficult to select the right device. Increasingly, companies are only able to promote a drug with the device that was used during the development program; therefore, choosing the best device at an early stage is important in order to achieve commercial success. Selecting a device that is inappropriate for the intended drug can result in poor drug delivery from the nebulizer to the patient, which would have obvious implications for the development program. As device performance varies, it is important to ensure that the most appropriate device is chosen for the intended drug to ensure optimal drug delivery to the patient population.

Areas covered: In this review, the types of nebulizer devices available are highlighted, and the factors that should be taken into consideration when selecting the most appropriate device for a new drug are discussed. The review is broadly divided into drug, device, patient and trial characteristics.

Expert opinion: Efficient nebulizer devices that combine electronic monitoring capabilities as a form of telehealth are likely to provide superior drug delivery to patients and accurate clinical trial data. Their use in adaptive clinical trials may help to vastly reduce the time and costs associated with achieving drug approval.     

Patient-reported outcome measurement in drug discovery: a tool to improve accuracy and completeness of efficacy and safety data

ABSTRACT

Introduction: Patient-reported outcomes (PROs) reflect how patients feel and function as conveyed directly by patients themselves, for example symptoms and physical functioning. PRO measures can be included in any phase of product development as primary, secondary, or exploratory endpoints to understand the impact of treatment on the patient experience.

Areas covered: In this review, the authors describe approaches commonly used to assess PROs in drug development programs, including how to select or develop outcomes and measures, implement these in trials, and analyze data. Barriers and facilitators for effectively including PROs in clinical trials are discussed, and strategies for making labeling claims based on PRO data are noted.

Expert opinion: Early planning with PRO experts is recommended to assure a successful PRO strategy in a product development program. Outcomes that are meaningful to patients should be rationally identified early in a product development program based on qualitative work, literature search and/or assumed mechanism of action. Measures corresponding to those outcomes should be selected or developed, with demonstration of robust psychometric properties in a related patient population. Ideally, these measures will be tested prior to a pivotal trial to support the design and analysis in the pivotal trial. Selection of timing and mode of assessments should be specified a priori and justified. If a labeling claim is sought, a statistical plan should be pre-specified. Strategies to minimize and handle missing data in analyses should be planned up front.     

Simulation Practices for Adaptive Trial Designs in Drug and Device Development

Abstract

Adaptive clinical trials are the cornerstone of modern drug and device development. The most recent US legislation calls for higher efficiency in designing clinical trials with emphasis on expanding the utilization of complex innovative designs that cannot be developed without simulations. It is well recognized that clinical trial simulation is a fundamental tool to explore, compare, and understand the operating characteristics, statistical properties, and adaptive decisions embedded in different designs to answer the given research questions. This article provides insights from industry on the development of a simulation report from a group of statisticians brought together under the sponsorship of the Drug Information Association Adaptive Design Scientific Working Group. This effort intends to illustrate the key common elements required to ensure higher consistency and clarity in conducting and reporting simulations of adaptive clinical trials, eliminate unnecessary barriers in communicating technical design aspects to different audiences, and facilitate the assessment of pros and cons of candidate designs. The design-dependent elements of a simulation report applicable to specific types of adaptive trials are presented with the examples of dose-escalation designs, dose-ranging studies, trials with sample size re-estimation and early stopping rules, and confirmatory multistage designs.     

Current pharmacological treatments for tinnitus

Introduction: Tinnitus, the phantom perception of sound, is a highly prevalent disorder and treatment is elusive.

Areas covered: This review focuses on clinical research regarding pharmacological treatments for tinnitus. The authors searched PubMed databases for English language articles related to pharmacological treatment of tinnitus, published through August 2012. The keywords "tinnitus AND pharmacological treatment” and “tinnitus AND drugs” were used. The search focused on clinical trials, but was complemented by other articles and information from clinical trial registries.

Expert opinion: Despite the significant unmet clinical need for a safe and effective drug for tinnitus relief, there is currently no EMA- or FDA-approved drug on the market. Even a drug that produces a small but significant effect would have a huge therapeutic impact. At present, evidence-based pharmacological approaches are limited to the treatment of comorbidities such as depression, anxiety, or insomnia. In the last few years there have been significant advances in the understanding of the pathophysiology of the different forms of tinnitus, the establishment of valid animal models, and the development of clinical trial methodology. A glimpse of hope is appearing in the horizon as an increasing number of pharmaceutical industries now have compounds targeting tinnitus in their pipeline.     

The safety of pharmacological treatment options for lupus nephritis

ABSTRACT

Introduction: The management of lupus nephritis (LN) has changed significantly over the last 10 years due to emerging evidence from large randomised clinical trials that produced good quality data and guided the formulation of two key concepts: the induction of remission and the maintenance phase of immunosuppressive therapy.

Areas covered: Optimizing cyclophosphamide and glucocorticoid regimens and the introduction of mycophenolate mofetil for proliferative and membranous LN has been pivotal. Nevertheless, concerns remain about treatment toxicity especially long term glucocorticoid use and exposure to cumulative cyclophosphamide doses. Here we discuss the conventional and newer pharmacological options for managing LN focusing on drug safety and toxicity issues.

Expert opinion: The need for effective and less toxic treatments led to the development of the role of targeted biologic therapies in LN. However, evidence from the initial randomized controlled trials has been disappointing, although this reflects inadequate trial design rather than true lack of efficacy.     

药物临床试验合同管理疑难问题对策研究

目的：分析药物临床试验合同管理中需解决的主要问题,并提出相应的对策建议,防范药物临床试验可能出现的风险。方法：查阅相关文献资料和法律法规,结合我国药物临床试验及药物临床试验机构合同管理现状,对药物临床试验合同进行分析研究。结果：合同主体、合同形式、合同涵盖内容包括受试者损害赔偿、试验费用、违约及终止、法律适用与管辖等,这些均是临床试验合同中的主要问题, 是药物临床试验管理的重要环节。结论：建议建立合理的合同审核机制,加强审核队伍建设,关注易出现问题的条款或争议条款,科学、规范地管理临床试验合同。