Efficient ways exist to obtain the optimal sample size in clinical trials in rare diseases

The quality of reporting in case reports of permanent neonatal diabetes mellitus: a cross-sectional study

BACKGROUND

Although randomized trials and systematic reviews provide the best evidence to guide medical practice, many permanent neonatal diabetes mellitus (PNDM) studies have been published as case reports. However, the quality of these studies has not been assessed. The purpose of this study was to assess the extent to which the current case reports for PNDM comply with the Case Report (CARE) guidelines and to explore variables associated with the reporting.

METHOD

Six English and four Chinese databases were searched from their inception to December 2022 for PNDM case reports. The 23 items CARE checklist was used to measure reporting quality. Primary outcome was the adherence rate of each CARE item and second outcome was total reporting score for each included PNDM case report. Linear and logistic regression analyses were used to examine the connection between five pre-specified predictor variables and the reporting quality. The predictor variables were impact factor of the published journal (<3.4 vs. ≥3.4, categorized according to the median), funding (yes vs. no), language (English vs. other language), published journal type (general vs. special) and year of publication (>2013 vs. ≤ 2013).

RESULT

In total, 105 PNDM case reports were included in this study. None of the 105 PNDM case reports fulfilled all 23 items of the CARE checklist. The response rate of 11 items were under 50%, including prognostic characteristics presentation (0%), patient perspective interpretation (0%), diagnostic challenges statement (2.9%), clinical course summary (21.0%), diagnostic reasoning statement (22.9%), title identification (24.8%), case presentation (33.3%), disease history description (34.3%), strengths and limitations explanation (41.0%), informed consent statement (45.7%), and lesson elucidation (47.6%). This study identified that the PNDM case reports published in higher impact factor journals were statistically associated with a higher reporting quality.

CONCLUSION

The reporting of case reports for PNDM is generally poor. As a result, this information may be misleading to providers, and the clinical applications may be detrimental to patient care. To improve reporting quality, journals should encourage strict adherence to the CARE guidelines.

Applying Monte Carlo Simulations to a Small Data Analysis of a Case of Economic Growth in COVID-19 Times

Studies on the going-on COVID-19 pandemic face small sample issues. In this context, Bayesian estimation is considered a viable alternative to frequentist estimation. Demonstrating the Bayesian approach's advantage in dealing with this problem, our research conducted a case study concerning ASEAN economic growth during the COVID-19 pandemic. By using Monte Carlo standard errors and interval hypothesis testing to check parameter bias within a Bayesian MCMC simulation study, the author obtained significant conclusions as follows: first, in insufficient sample sizes, in contrast to frequentist estimation, the Bayesian framework can offer meaningful results, that is, expansionary monetary and contractionary fiscal policies are positively associated with economic growth; second, in the face of a small sample, by incorporating more information into prior distributions for the model parameters, Bayesian Monte Carlo simulations perform so far better than naïve Bayesian and frequentist estimation; third, in case of a correctly specified prior, the inferences are robust to different prior specifications. The author strongly recommends applying specific informative priors to Bayesian analyses, particularly in small sample investigations.

Non-static framework for understanding adaptive designs: an ethical justification in paediatric trials

Many drugs used in paediatric medicine are off-label. There is a rising call for the use of adaptive clinical trial designs (ADs) in responding to the need for safe and effective drugs given their potential to offer efficiency and cost-effective benefits compared with traditional clinical trials. ADs have a strong appeal in paediatric clinical trials given the small number of available participants, limited understanding of age-related variability and the desire to limit exposure to futile or unsafe interventions. Although the ethical value of adaptive trials has increasingly come under scrutiny, there is a paucity of literature on the ethical dilemmas that may be associated with paediatric adaptive designs (PADs). This paper highlights some of these ethical concerns around safety, scientific/social value and caregiver/guardian comprehension of the trial design. Against this background, the paper develops a non-static conceptual lens for understanding PADs. It shows that ADs are epistemically open and reduce some of the knowledge-associated uncertainties inherent in clinical trials as well as fast-track the time to draw conclusions about the value of evaluated drugs/treatments. On this note, the authors argue that PADs are ethically justifiable given they (1) have multiple layers of safety, exposing enrolled children to lesser potential risks, (2) create social/scientific value generally and for paediatric populations in particular, (3) specifically foster the flourishing of paediatric populations and (4) can significantly improve paediatric trial efficiency when properly designed and implemented. However, because PADs are relatively new and their regulatory, ethical and logistical characteristics are yet to be clarified in some jurisdictions, the cooperation of various public and private stakeholders is required to ensure that the interests of children, their caregivers and parents/guardians are best served while exposing paediatric research subjects to the most minimal of risks when they are enrolled in paediatric trials that use ADs.

Randomized and non-randomized designs for causal inference with longitudinal data in rare disorders

In the United States, approximately 7000 rare diseases affect 30 million patients, and only 10% of these diseases have existing therapies. Sound study design and causal inference methods are essential to demonstrate the therapeutic efficacy, safety, and effectiveness of new therapies. In the rare diseases setting, several factors challenge the use of typical parallel control designs: the small patient population size, genotypic and phenotypic diversity, and the complexity and incomplete understanding of the disorder’s progression. Repeated measures, when spaced appropriately relative to disease progression and exploited in design and analysis, can increase study power and reduce variability in treatment effect estimation. This paper reviews these longitudinal designs and draws the parallel between some new and existing randomized studies in rare diseases and their less well-known controlled observational study designs. We show that self-controlled randomized crossover and N-of-1 designs have similar considerations as the observational case series and case-crossover designs. Also, randomized sequential designs have similar considerations to longitudinal cohort studies using sequential matching or weighting to control confounding. We discuss design and analysis considerations for valid causal inference and illustrate them with examples of analyses in multiple rare disorders, including urea cycle disorder and cystic fibrosis.

Finding commonalities in rare diseases through the undiagnosed diseases network

Objective

When studying any specific rare disease, heterogeneity and scarcity of affected individuals has historically hindered investigators from discerning on what to focus to understand and diagnose a disease. New nongenomic methodologies must be developed that identify similarities in seemingly dissimilar conditions.

Materials and Methods

This observational study analyzes 1042 patients from the Undiagnosed Diseases Network (2015-2019), a multicenter, nationwide research study using phenotypic data annotated by specialized staff using Human Phenotype Ontology terms. We used Louvain community detection to cluster patients linked by Jaccard pairwise similarity and 2 support vector classifier to assign new cases. We further validated the clusters’ most representative comorbidities using a national claims database (67 million patients).

Results

Patients were divided into 2 groups: those with symptom onset before 18 years of age (n = 810) and at 18 years of age or older (n = 232) (average symptom onset age: 10 [interquartile range, 0-14] years). For 810 pediatric patients, we identified 4 statistically significant clusters. Two clusters were characterized by growth disorders, and developmental delay enriched for hypotonia presented a higher likelihood of diagnosis. Support vector classifier showed 0.89 balanced accuracy (0.83 for Human Phenotype Ontology terms only) on test data.

Discussions

To set the framework for future discovery, we chose as our endpoint the successful grouping of patients by phenotypic similarity and provide a classification tool to assign new patients to those clusters.

Conclusion

This study shows that despite the scarcity and heterogeneity of patients, we can still find commonalities that can potentially be harnessed to uncover new insights and targets for therapy.

Safety and Efficacy of Intermittent Colonic Exoperistalsis Device to Treat Chronic Constipation: A Prospective Multicentric Clinical Trial

Chronic constipation is associated with various comorbidities and reduced quality of life. Current solutions, either pharmacological or invasive, show limited efficacy. Manual colon-specific massage is a well-established intervention to treat chronic constipation, but it should be applied daily. MOWOOT automatically provides intermittent colonic exo-peristalsis (ICE) treatment like that in manual massage.

Clinical and Translational Research Challenges in Neuroendocrine Tumours

Neuroendocrine tumours (NETs) represent a range of neoplasms that may arise from any (neuro)endocrine cell situated in any part of the human body. As any other rare diseases, NETs face several difficulties in relation to research. This review will describe some of the main challenges and proposed solutions faced by researchers with expertise in rare malignancies. Some of the most common challenges in clinical and translational research are enumerated in this review, covering aspects from clinical, translational and basic research. NETs being a heterogeneous group of diseases and a limited sample size of clinical and translational research projects are the main challenges. Challenges with NETs lay over the disparities between healthcare models to tackle rare diseases. NETs add an extra layer of complexity due to a numerous group of different entities. Prospective real-world data trials are an opportunity for rare cancers with the revolution of electronic health technologies. This review explores potential solutions to these challenges that could be useful not only to the NET community but also to other rare tumours researchers.

Medical costs of Alpha-1 antitrypsin deficiency-associated COPD in the United States

Background

There are limited data on economic aspects of the genetic variant of chronic obstructive pulmonary disease (COPD) in the context of the more prevalent form of COPD. The objective of this study was to isolate the healthcare resource utilization and economic burden attributable to the presence of a genetic factor among COPD patients with and without Alpha-1 Antitrypsin Deficiency (AATD), twelve months before and after their initial COPD diagnosis.

Methods

Retrospective analysis of OptumLabs® Data Warehouse claims (OLDW; 2000–2017). The OLDW is a comprehensive, longitudinal real-world data asset with de-identified lives across claims and clinical information. AATD-associated COPD cases were matched with up to 10 unique non-AATD-associated COPD controls. Healthcare resource use and costs were assigned into the following categories: office (OV), outpatient (OP), and emergency room visits (ER), inpatients stays (IP), prescription drugs (RX), and other services (OTH). A generalized linear model was used to estimate total pre- and post-index (initial COPD diagnosis) costs from a third-party payer’s perspective (2018 USD) controlling for confounders. Healthcare resource utilization was estimated using a negative binomial regression.

Results

The study population consisted of 8881 patients (953 cases matched with 7928 controls). The AATD-associated COPD cohort had higher expenditures and use of office visits (OV) and other (OTH) services, as well as OV, outpatient (OP), emergency room (ER), and prescription drugs (RX) before and after the index date, respectively. Adjusted total all-healthcare cost ratios for AATD-associated COPD patients as compared to controls were 2.04 [95% CI: 1.60–2.59] and 1.98 [95% CI: 1.55–2.52] while the incremental cost difference totaled $6861 [95% CI: $3025 - $10,698] and $5772 [95% CI: $1940 - $9604] per patient before and after the index date, respectively.

Conclusions

Twelve months before and after their initial COPD diagnosis, patients with AATD incur higher healthcare utilization costs that are double the cost of similar COPD patients without AATD. This study also suggests that increased costs of AATD-associated COPD are not solely attributable to augmentation therapy use. Future studies should further explore the relationship between augmentation therapy, healthcare resource use, and other AATD-associated COPD expenditures.

The world is waiting, use sequential analysis and get us the evidence-based treatment we need for COVID-19

In spite of the relatively high morbidity and mortality, there is no approved medication yet for COVID-19. There are more than 200 ongoing trials on different drugs or vaccines, but new medications may take until 2021 to develop. Defining the optimal number of patients to be included in a study is a considerable challenge in these interventional researches. Ethical considerations prompt researchers to minimize the number of patients included in a trial. This gains particular importance when the disease is rare or lethal which is particularly so in the case of COVID-19. It is of paramount importance to explore some of the available tools that could help accelerate the adoption of any or some of the many proposed modalities for the treatment of diseases. These tools should be effective, yet efficient, for rapid testing of such treatments. Sequential analysis has not been frequently used in many clinical trials where it should have been used. None of the authors in published literature, as far as we know, used sequential analysis techniques to test potential drugs for COVID-19. In addition to its usefulness when the results of new forms of treatment are quickly needed, other important benefit of sequential analysis includes the ability to reach a similar conclusion about the utility of a new drug without unduly exposing more patients to the side effect of the old drug, in particularly, for the treatment of a rare disease.

C5 Convertase Blockade in Membranoproliferative Glomerulonephritis: A Single-Arm Clinical Trial

RATIONALE & OBJECTIVE

Primary membranoproliferative glomerulonephritis (MPGN) is a rare glomerulopathy characterized by complement dysregulation. MPGN progresses rapidly to kidney failure when it is associated with nephrotic syndrome. We assessed the effects of C5 convertase blockade in patients with MPGN and terminal complement activation.

STUDY DESIGN

Prospective off-on-off-on open-label clinical trial.

SETTING & PARTICIPANTS

Consenting patients with immune complex-mediated MPGN (n=6) or C3 glomerulonephritis (n=4) with sC5b-9 (serum complement membrane attack complex) plasma levels>1,000ng/mL and 24-hour proteinuria with protein excretion>3.5g identified from the Italian Registry of MPGN and followed up at the Istituto di Ricerche Farmacologiche Mario Negri IRCCS (Bergamo, Italy) between March 4, 2014, and January 7, 2015.

INTERVENTION

Anti-C5 monoclonal antibody eculizumab administered during 2 sequential 48-week treatment periods separated by one 12-week washout period.

OUTCOMES

Primary outcome was change in 24-hour proteinuria (median of 3 consecutive measurements) at 24 and 48 weeks.

RESULTS

Median proteinuria decreased from protein excretion of 6.03 (interquartile range [IQR], 4.8-12.4) g/d at baseline to 3.74 (IQR, 3.2-4.4) g/d at 24 weeks (P=0.01) and to 5.06 (IQR, 3.1-5.8) g/d (P=0.006) at 48 weeks of treatment, recovered toward baseline during the washout period, and did not significantly decrease thereafter. Hypoalbuminemia, dyslipidemia, and glomerular sieving function improved during the first treatment period. 3 patients achieved partial remission of nephrotic syndrome and all had undetectable C3 nephritic factors before treatment. Mean measured glomerular filtration rate was 69.7±35.2 versus 87.4±55.1 and 75.8±42.7 versus 76.6±44.1mL/min/1.73m² at the start versus the end of the first and second treatment periods, respectively, among all 10 study participants. Unlike C3, sC5b-9 plasma levels normalized during both treatment periods and recovered toward baseline during the washout in all patients.

LIMITATIONS

Single-arm design, small sample size.

CONCLUSIONS

Eculizumab blunted terminal complement activation in all patients with immune complex-mediated MPGN or C3 glomerulonephritis and nephrotic syndrome, but persistently reduced proteinuria in just a subgroup.

TRIAL REGISTRATION

Registered in the EU Clinical Trials Register with study no. 2013-003826-10.

Considerations for adaptive design in pediatric clinical trials: study protocol for a systematic review, mixed-methods study, and integrated knowledge translation plan

Background

Although children have historically been excluded from clinical trials (CTs), many require medicines tested and approved in CTs, forcing health care providers to treat their pediatric patients based on extrapolated data. Unfortunately, traditional randomized CTs can be slow and resource-intensive, and they often require multi-center collaboration. However, an adaptive design (AD) framework for CTs could be used to increase the efficiency of pediatric CTs by incorporating prospectively planned modifications to CT methods without undermining the integrity or validity of the study. There are many possible adaptations, but each will have ethical, logistical, and statistical implications. It remains unclear which adaptations (or combinations thereof) will lead to real-world improvements in pediatric CT efficiency. This study will identify, evaluate, and synthesize the various regulatory, ethical, logistical, and statistical considerations and emerging issues of AD in CTs that could be used to evaluate the use of drugs in children.

Methods/design

Following the development of a peer-reviewed search strategy, a systematic review on AD in CTs will be conducted. Data on regulatory, ethical, logistic, and statistical considerations as well as population and trial design characteristics will be synthesized. A mixed-methods study including surveys and focus groups with regulators, research ethics board members, biostatisticians, clinicians, and scientists, as well as representatives from patient groups and the public will evaluate the opportunities and challenges in applying AD in trials enrolling children and propose recommendations on best practices.

Discussion

This study will deliver practical recommendations on the use of AD in pediatric CTs. Collaboration and consultation with national and global partners will ensure that our results meet the needs of researchers, regulators, and patients, both locally and globally, and that they remain current and relevant by engaging a wide variety of stakeholders. Overall, this research will enrich the knowledge base regarding if, how, and when AD can be used to answer research questions with fewer resources while still meeting the highest ethical standards and regulatory requirements for CTs. In turn, this will result in increased high-quality clinical research needed by health care providers so they have access to appropriate, population-specific evidence regarding the safe and effective use of medicines in children.

Using a meta-narrative literature review and focus groups with key stakeholders to identify perceived challenges and solutions for generating robust evidence on the effectiveness of treatments for rare diseases

INTRODUCTION

For many rare diseases, strong analytic study designs for evaluating the efficacy and effectiveness of interventions are challenging to implement because of small, geographically dispersed patient populations and underlying clinical heterogeneity. The objective of this study was to integrate perspectives from published literature and key rare disease stakeholders to better understand the perceived challenges and proposed methodological approaches to research on clinical interventions for rare diseases.

METHODS

We used a meta-narrative literature review and focus group interviews with key rare disease stakeholders to better understand the perceived challenges in generating and synthesizing treatment effectiveness evidence, and to describe various research methods for mitigating these identified challenges. Data from both components of this study were synthesized narratively according to research paradigms that emerged from our data.

RESULTS

Results from our meta-narrative literature review and focus group interviews revealed three fundamental challenges in generating robust treatment effectiveness evidence for rare diseases: i) limitations in recruiting a sufficient sample size to achieve planned statistical power; ii) inability to account for clinical heterogeneity and assess treatment effects across a clinical spectrum; and iii) reliance on short-term, surrogate outcomes whose clinical relevance is often unclear. We mapped these challenges and associated solutions to three interrelated research paradigms: i) explanatory evidence generation; ii) comparative effectiveness/pragmatic evidence generation; and iii) patient-oriented evidence generation. Within each research paradigm, numerous criticisms and potential solutions have been described with respect to overcoming these challenges from a research study design perspective.

CONCLUSIONS

Over time, discussions about clinical research for interventions for rare diseases have moved beyond methodological approaches to overcome challenges related to explanatory evidence generation, with increased recognition of the importance of pragmatic and patient-oriented evidence. Future directions for our work include developing a framework to expand current evidence synthesis practices to take into consideration many of the concepts discussed in this paper.

Randomized controlled trials in pediatric patients had higher completion rates than adult trials: a cross-sectional study

OBJECTIVE

Conduct of clinical trials is perceived to be more challenging in children than in adults. This study aimed to evaluate the impact of the age of participants on completion rates of randomized controlled trials (RCTs).

STUDY DESIGN AND SETTING

A cross-sectional study on RCTs registered in the ClinicalTrials.gov database. All RCTs registered up to December 31, 2016, were extracted and were classified according to their recruitment status: active, completed, or discontinued and according to the age of participants: children (<17 years), adults (≥18 years), and mixed-age population. A logistic regression model was applied to assess the impact of participant's age category on trial completion while controlling for other relevant trial features.

RESULTS

A total of 65,095 registered RCTs were identified. Among pediatric trials, 49.9% were completed and 8.5% were discontinued. Among adult and mixed age RCTs, respectively, 49.7% and 47.9% were completed whereas, 10.2% and 9.4% were discontinued. Overall, pediatric and mixed age RCTs were more likely to be registered as completed than adult RCTs (odds ratio: 1.16, 95% CI: 1.02-1.30; odds ratio: 1.15, 95% CI: 1.04-1.27, respectively). Also, funding source, type of intervention under evaluation, primary trial purpose, use of a blinding procedure, use of a placebo, and participants' assignment model were identified as independent predictors of RCT completion.

CONCLUSION

Contrary to current perceptions and despite several specific challenges, recruitment of children and adolescents is not a limiting factor to completing a RCT. Other study features such as funding source, impact completeness and should be carefully considered before initiating research.

Increasing the efficiency of clinical trials in neurodegenerative disorders using group sequential trial designs

OBJECTIVES

Clinical trials in neurodegenerative disorders are facing high futility rates and rising development costs. We aim to review and exemplify the value of group sequential trial designs (i.e., designs with one or more prospectively planned interim analyses) within the field of amyotrophic lateral sclerosis.

STUDY DESIGN AND SETTING

We reviewed the literature to identify sequentially conducted trials. Subsequently, we reanalyzed the dexpramipexole trial (EMPOWER), a classically designed and conducted trial involving 942 participants, by sequentially monitoring the functional questionnaire and survival endpoint. Finally, we simulated the performance of the sequential methodology under different treatment effects.

RESULTS

Only six (12%) randomized, placebo-controlled trials incorporated stopping rules for both futility and superiority. Despite its high enrollment rate, sequential reanalysis of the EMPOWER study reduced the total trial duration with 140 days (23.4%, 95% confidence interval [CI] 13.2-34.4%), the number of follow-ups with 2,688 visits (23.6%, 95% CI 11.3-38.6%), and the total drug exposure time with 73,377 days (20.6%, 95% CI 9.8-35.9%). The functional questionnaire considerably increased the heterogeneity in the test statistics, which may negatively affect sequential monitoring.

CONCLUSION

Group sequential trials can result in important reductions in the trial duration, which could make clinical trials more ethical by reducing the patients' exposure to noneffective treatments or by limiting their time on placebo.

An overview of the impact of rare disease characteristics on research methodology

Background

About 30 million individuals in the United States are living with a rare disease, which by definition have a prevalence of 200,000 or fewer cases in the United States ([National Organization for Rare Disorders], [About NORD], [2016]). Disease heterogeneity and geographic dispersion add to the difficulty of completing robust studies in small populations. Improving the ability to conduct research on rare diseases would have a significant impact on population health. The purpose of this paper is to raise awareness of methodological approaches that can address the challenges to conducting robust research on rare diseases.

Approach

We conducted a landscape review of available methodological and analytic approaches to address the challenges of rare disease research. Our objectives were to: 1. identify algorithms for matching study design to rare disease attributes and the methodological approaches applicable to these algorithms; 2. draw inferences on how research communities and infrastructure can contribute to the efficiency of research on rare diseases; and 3. to describe methodological approaches in the rare disease portfolio of the Patient-Centered Outcomes Research Institute (PCORI), a funder promoting both rare disease research and research infrastructure.

Results

We identified three algorithms for matching study design to rare disease or intervention characteristics (Gagne, et.al, BMJ 349:g6802, 2014); (Gupta, et.al, J Clin Epidemiol 64:1085-1094, 2011); (Cornu, et. al, Orphet J Rare Dis 8:48,2012) and summarized the applicable methodological and analytic approaches. From this literature we were also able to draw inferences on how an effective research infrastructure can set an agenda, prioritize studies, accelerate accrual, catalyze patient engagement and terminate poorly performing studies. Of the 24 rare disease projects in the PCORI portfolio, 11 are randomized controlled trials (RCTs) using standard designs. Thirteen are observational studies using case-control, prospective cohort, or natural history designs. PCORI has supported the development of 9 Patient-Powered Research Networks (PPRNs) focused on rare diseases.

Conclusion

Matching research design to attributes of rare diseases and interventions can facilitate the completion of RCTs that are adequately powered. An effective research infrastructure can improve efficiency and avoid waste in rare disease research. Our review of the PCORI research portfolio demonstrates that it is feasible to conduct RCTs in rare disease. However, most of these studies are using standard RCT designs. This suggests that use of a broader array of methodological approaches to RCTs --such as adaptive trials, cross-over trials, and early escape designs can improve the productivity of robust research in rare diseases.

Alternative designs for clinical trials in rare diseases

Evidence-based medicine requires strong scientific evidence upon which to base treatment. In rare diseases, study populations are often small, and thus this evidence is difficult to accrue. Investigators, though, should be creative and develop a flexible toolkit of methods to deal with the problems inherent in the study of rare disease. This narrative review presents alternative clinical trial designs for studying treatments of rare diseases, including cross-over and n-of-1 trials, randomized placebo-phase design, enriched enrollment, randomized withdrawal design, and classes of adaptive designs. Examples of applications of these designs are presented along with their advantages and disadvantages. Additional analytical considerations such as Bayesian analysis, internal pilots, and use of biomarkers as surrogate outcomes are further discussed. A framework for selecting appropriate clinical trial design is proposed to guide investigators in the process of selecting alternative designs for rare diseases. © 2016 Wiley Periodicals, Inc.

Good-quality research in rare diseases: trials and tribulations

Despite the fact that rare diseases affecting the kidney are not as uncommon as generally believed, proper clinical guidelines for guiding therapeutic management are scarce or absent owing to the overall lack of reliable scientific evidence. Although the randomized controlled trial (RCT) is the best study design for dealing with questions of intervention, RCTs under low-prevalence conditions are extremely challenging because of the limited number of patients, the variable phenotypic expression, and the long course of these disorders. In this brief review, we aimed to summarize the main alternative methods to traditional RCTs designed with the intent of minimizing the number of subjects needed for recruitment or maximizing the statistical efficiency of study analyses. Most of these approaches have not yet been extensively employed, may denote crucial limitations to wide applicability, or still lack proper validation in the field of rare diseases. Nevertheless, the growing number of proposed strategies is indicative of the perceived necessity by the scientific community to fill the quality gap between clinical guidelines for common and rare pathological conditions.

Design and conduct of early phase drug studies in children: challenges and opportunities

It has historically been very difficult to conduct early phase drug studies in children for a number of reasons related to ethics, acceptability, rarity, standardization, end points, safety, dosing and feasibility. Over the past decade there have been a number of developments including novel clinical trial design, in silico pharmacology and microdosing that have significantly enhanced the ability of investigators to conduct early phase drug studies in children. While the evolution of drug therapy is creating a series of new challenges, there has never been a better time for conducting drug studies in children.

Development and use of new therapeutics for rare diseases: views from patients, caregivers, and advocates

BACKGROUND

Patients with rare diseases experience the health care system differently than patients with more common conditions. They can therefore provide important perspectives on the process of developing therapeutics for their conditions.

METHODS

We conducted three in-person focus groups involving rare disease patients (n = 9), caregivers (n = 8), and advocates (n = 9). Focus group participants were asked to describe their experiences with a rare disease, what they would want to know about a new drug for the disease, what outcomes they believe should be assessed in drug testing, perceptions of off-label use of a drug for treating a rare disease, views on participation in clinical trials, and opinions of the US Food and Drug Administration's (FDA's) function. The coding structure was populated from the transcripts of the sessions, using Atlas.ti qualitative analysis software, and then analyzed for common themes.

RESULTS

Participants described the challenges of learning to live with a poorly understood condition for which treatment is limited. Rare disease patients were willing to accept certain risks in their care in the hopes of finding some benefit, but also expressed frustrations with the costs of their care and the lack of scientific data about their treatments. They were concerned that the development and testing of therapies should, as quickly as possible, yield effective treatments to advance their quality of life.

CONCLUSION

With limited therapeutic options, rare disease patients often considered off-label treatments or novel drugs that posed substantial risk. Nonetheless, rare disease patients generally appreciated the rigor of the research underlying the drugs and supported the FDA's gatekeeping role.

Sequential designs with small samples: Evaluation and recommendations for normal responses

Sequential monitoring is a well-known methodology for the design and analysis of clinical trials. Driven by the lower expected sample size, recent guidelines and published research suggest the use of sequential methods for the conduct of clinical trials in rare diseases. However, the vast majority of the developed and most commonly used sequential methods relies on asymptotic assumptions concerning the distribution of the test statistics. It is not uncommon for trials in (very) rare diseases to be conducted with only a few decades of patients and the use of sequential methods that rely on large-sample approximations could inflate the type I error probability. Additionally, the setting of a rare disease could make the traditional paradigm of designing a clinical trial (deciding on the sample size given type I and II errors and anticipated effect size) irrelevant. One could think of the situation where the number of patients available has a maximum and this should be utilized in the most efficient way. In this work, we evaluate the operational characteristics of sequential designs in the setting of very small to moderate sample sizes with normally distributed outcomes and demonstrate the necessity of simple corrections of the critical boundaries. We also suggest a method for deciding on an optimal sequential design given a maximum sample size and some (data driven or based on expert opinion) prior belief on the treatment effect.

Rett Syndrome: Crossing the Threshold to Clinical Translation

Lying at the intersection between neurobiology and epigenetics, Rett syndrome (RTT) has garnered intense interest in recent years, not only from a broad range of academic scientists, but also from the pharmaceutical and biotechnology industries. In addition to the critical need for treatments for this devastating disorder, optimism for developing RTT treatments derives from a unique convergence of factors, including a known monogenic cause, reversibility of symptoms in preclinical models, a strong clinical research infrastructure highlighted by an NIH-funded natural history study and well-established clinics with significant patient populations. Here, we review recent advances in understanding the biology of RTT, particularly promising preclinical findings, lessons from past clinical trials, and critical elements of trial design for rare disorders.

Research methods to change clinical practice for patients with rare cancers

Rare cancers are a growing group as a result of reclassification of common cancers by molecular markers. There is therefore an increasing need to identify methods to assess interventions that are sufficiently robust to potentially affect clinical practice in this setting. Methods advocated for clinical trials in rare diseases are not necessarily applicable in rare cancers. This Series paper describes research methods that are relevant for rare cancers in relation to the range of incidence levels. Strategies that maximise recruitment, minimise sample size, or maximise the usefulness of the evidence could enable the application of conventional clinical trial design to rare cancer populations. Alternative designs that address specific challenges for rare cancers with the aim of potentially changing clinical practice include Bayesian designs, uncontrolled n-of-1 trials, and umbrella and basket trials. Pragmatic solutions must be sought to enable some level of evidence-based health care for patients with rare cancers.

Changing the Paradigm for the Treatment and Development of New Therapies for FSGS

Focal segmental glomerulosclerosis (FSGS) is a renal pathology finding that represents a constellation of rare kidney diseases, which manifest as proteinuria, edema nephrotic syndrome, hypertension, and increased risk for kidney failure. Therapeutic options for FSGS are reviewed displaying the expected efficacy from 25 to 69% depending on specific therapy, patient characteristics, cost, and common side effects. This variability in treatment response is likely caused, in part, by the heterogeneity in the etiology and active molecular mechanisms of FSGS. Clinical trials in FSGS have been scant in number and slow to recruit, which may stem, in part, from reliance on classic clinical trial design paradigms. Traditional clinical trial designs based on the "learn and confirm" paradigm may not be appropriate for rare diseases, such as FSGS. Future drug development and testing will require novel approaches to trial designs that have the capacity to enrich study populations and adapt the trial in a planned way to gain efficiencies in trial completion timelines. A clinical trial simulation is provided that compares a classical and more modern design to determine the maximum tolerated dose in FSGS.

Improving evidence on anticoagulant therapies for venous thromboembolism in children: key challenges and opportunities

Venous thromboembolism (VTE) is increasingly diagnosed in pediatric patients, and anticoagulant use in this population has become common, despite the absence of US Food and Drug Administration (FDA) approval for this indication. Guidelines for the use of anticoagulants in pediatrics are largely extrapolated from large randomized controlled trials (RCTs) in adults, smaller dose-finding and observational studies in children, and expert opinion. The recently FDA-approved direct oral anticoagulants (DOACs), such as dabigatran, rivaroxaban, apixaban, and edoxaban, provide potential advantages over oral vitamin K antagonists and subcutaneous low-molecular-weight heparins (LMWHs). However, key questions arise regarding their potential off-label clinical application in pediatric thromboembolic disease. In this Perspective, we provide background on the use of LMWHs such as enoxaparin as the mainstay of treatment of pediatric provoked VTE; identify key questions and challenges with regard to DOAC trials and future DOAC therapy in pediatric VTE; and discuss applicable lessons learned from the recent pilot/feasibility phase of a large multicenter RCT of anticoagulant duration in pediatric VTE. The challenges and lessons learned present opportunities to improve evidence for anticoagulant therapies in pediatric VTE through future clinical trials.

Innovative research methods for studying treatments for rare diseases: methodological review

OBJECTIVE

To examine methods for generating evidence on health outcomes in patients with rare diseases.

DESIGN

Methodological review of existing literature.

SETTING

PubMed, Embase, and Academic Search Premier searched for articles describing innovative approaches to randomized trial design and analysis methods and methods for conducting observational research in patients with rare diseases.

MAIN OUTCOME MEASURES

We assessed information related to the proposed methods, the specific rare disease being studied, and outcomes from the application of the methods. We summarize methods with respect to their advantages in studying health outcomes in rare diseases and provide examples of their application.

RESULTS

We identified 46 articles that proposed or described methods for studying patient health outcomes in rare diseases. Articles covered a wide range of rare diseases and most (72%) were published in 2008 or later. We identified 16 research strategies for studying rare disease. Innovative clinical trial methods minimize sample size requirements (n=4) and maximize the proportion of patients who receive active treatment (n=2), strategies crucial to studying small populations of patients with limited treatment choices. No studies describing unique methods for conducting observational studies in patients with rare diseases were identified.

CONCLUSIONS

Though numerous studies apply unique clinical trial designs and considerations to assess patient health outcomes in rare diseases, less attention has been paid to innovative methods for studying rare diseases using observational data.

Methodological choices for the clinical development of medical devices

Clinical evidence available for the assessment of medical devices (MDs) is frequently insufficient. New MDs should be subjected to high quality clinical studies to demonstrate their benefit to patients. The randomized controlled trial (RCT) is the study design reaching the highest level of evidence in order to demonstrate the efficacy of a new MD. However, the clinical context of some MDs makes it difficult to carry out a conventional RCT. The objectives of this review are to present problems related to conducting conventional RCTs and to identify other experimental designs, their limitations, and their applications. A systematic literature search was conducted for the period January 2000 to July 2012 by searching medical bibliographic databases. Problems related to conducting conventional RCTs of MDs were identified: timing the assessment, eligible population and recruitment, acceptability, blinding, choice of comparator group, and learning curve. Other types of experimental designs have been described. Zelen's design trials and randomized consent design trials facilitate the recruitment of patients, but can cause ethical problems to arise. Expertise-based RCTs involve randomization to a team that specializes in a given intervention. Sometimes, the feasibility of an expertise-based randomized trial may be greater than that of a conventional trial. Cross-over trials reduce the number of patients, but are not applicable when a learning curve is required. Sequential trials have the advantage of allowing a trial to be stopped early depending on the results of first inclusions, but they require an independent committee. Bayesian methods combine existing information with information from the ongoing trial. These methods are particularly useful in situations where the number of subjects is small. The disadvantage is the risk of including erroneous prior information. Other types of experimental designs exist when conventional trials cannot always be applied to the clinical development of MDs.

What are the long-term effects of treatment on survivors of childhood leukaemia? A review of the literature

Purpose

Key advances in cancer treatment have led to an increasing number of long-term cancer survivors. Knowledge of the long-term effects of cancer treatment on leukaemia survivors is to some degree limited. This article investigates the effects of the treatment of childhood leukaemia on the quality of life (QOL), the physical and the psychological wellbeing and general development of survivors. This article reviews current literature to examine existing gaps in knowledge and identify a potential focus of future research and clinical practice.

Materials and methods

Online systematic searching, along with historical searching took place in order to retrieve relevant primary research papers for the review. Strict inclusion and exclusion criteria were applied to the literature, to create a manageable amount of research papers.

Results

The extent of intellectual impairment among radiotherapy patients was significantly greater than those treated with chemotherapy only. Body composition, including endocrine function, is readily affected by cancer treatment. Early identification and interventions can greatly improve the QOL of survivors.

Conclusion

Further research into the effect of treatment modality on the extent of chronic effects, along with investigations into the needs of the whole family unit, is required. Future practice must take into account long-term implications while ensuring effective holistic care.

Clinical evidence for orphan medicinal products-a cause for concern?

Background

The difficulties associated with organising clinical studies for orphan medicinal products (OMPs) are plentiful. Recent debate on the long-term effectiveness of some OMPs, led us to question whether the initial standards for clinical evidence for OMPs, set by the European Medicines Agency (EMA) at the time of marketing authorization, are too low. Therefore, the aim of this study was to quantitatively evaluate the characteristics and quality of clinical evidence that is presented for OMPs to obtain marketing authorization in Europe, using the new and validated COMPASS tool.

Methods

We quantitatively assessed the characteristics and quality of clinical evidence of the pivotal studies of 64 OMPs as described in the European Public Assessment Report and/or the Scientific Discussion document prepared by the Committee for Human Medicinal Products of the EMA.

Results

The 64 OMPs were altogether authorized for 78 orphan indications, for which 117 studies were identified as 'pivotal’ or 'main’ studies. In approximately two thirds of the studies, the allocation was randomized (64.8%) and a control arm was used (68.5%). Half of the studies applied some type of blinding. Only a minority (26.9%) of the studies included a Quality-of-Life (QoL) related endpoint, of which a third claim an improvement in QoL. Upon analyzing the quality of reporting, we found that some aspects (i.e. the endpoints, the sampling criteria, and the interventions) are well described, whereas other items (i.e. a description of the patients and of potential biases) are not reported for all studies.

Conclusions

In conclusion, the pivotal studies that are the basis for marketing authorization of OMPs are a cause for concern, as they exhibit methodological flaws i.e. the lack of QoL-related endpoints as outcome, lack of blinding in the study design and the use of surrogate endpoints. Additionally, there are shortcomings in the reporting of those studies that complicate the interpretation. A more demanding regulatory process for OMPs is needed to guide evidence-based clinical decision-making.

Gastrostomy matters--the impact of pediatric surgery on caregiver quality of life

INTRODUCTION

While pediatric surgeons consider gastrostomy to be routine treatment for children with feeding difficulties, the impact on the family is not fully understood. This study focuses on Quality of Life (QoL) of parents of children who require a gastrostomy tube.

METHODS

A prospective repeated measures cohort study was conducted between November 2009 and March 2012. Demographic, surgical, and QoL data were collected at Baseline, 2 weeks, 3, 6, 9, and 12 months after surgery. At each time-point parents completed three QoL measures: Short Form 36v2 (SF-36), Caregiver Strain Index (CSI), and Parent Experience of Childhood Illness (PECI).

RESULTS

A total of 31 caregivers were recruited with a mean age of 32.6 years (SD=7.0). Overall, a 38% increased risk of depression was seen in the SF-36 when compared to population norms, and a moderate effect was seen in mental health at 12 months (ES=0.56). The CSI demonstrated a decrease in caregiver burden (8.72 to 7.05, p=0.007, 95% CI (0.57-3.18)), while the PECI revealed a decrease in frequency of feelings of guilt, worry, sorrow, anger, and long term uncertainty over 12 months.

CONCLUSION

Gastrostomy not only improves the child's physical health, but also improves the mental health of the child's caregivers, especially at (or after) one year.

SPIRIT 2013 explanation and elaboration: guidance for protocols of clinical trials

High quality protocols facilitate proper conduct, reporting, and external review of clinical trials. However, the completeness of trial protocols is often inadequate. To help improve the content and quality of protocols, an international group of stakeholders developed the SPIRIT 2013 Statement (Standard Protocol Items: Recommendations for Interventional Trials). The SPIRIT Statement provides guidance in the form of a checklist of recommended items to include in a clinical trial protocol. This SPIRIT 2013 Explanation and Elaboration paper provides important information to promote full understanding of the checklist recommendations. For each checklist item, we provide a rationale and detailed description; a model example from an actual protocol; and relevant references supporting its importance. We strongly recommend that this explanatory paper be used in conjunction with the SPIRIT Statement. A website of resources is also available (www.spirit-statement.org). The SPIRIT 2013 Explanation and Elaboration paper, together with the Statement, should help with the drafting of trial protocols. Complete documentation of key trial elements can facilitate transparency and protocol review for the benefit of all stakeholders.

Patient recruitment into a multicenter randomized clinical trial for kidney disease: report of the focal segmental glomerulosclerosis clinical trial (FSGS CT)

We describe the experience of the focal segmental glomerulosclerosis clinical trial (FSGS CT) in the identification and recruitment of participants into the study. This National Institutes of Health funded study, a multicenter, open-label, randomized comparison of cyclosporine versus oral dexamethasone pulses plus mycophenolate mofetil, experienced difficulty and delays meeting enrollment goals. These problems occurred despite the support of patient advocacy groups and aggressive recruitment strategies. Multiple barriers were identified including: (1) inaccurate estimates of the number of potential incident FSGS patients at participating centers; (2) delays in securing one of the test agents; (3) prolonged time between IRB approval and execution of a subcontract (mean 7.5 ± 0.8 months); (4) prolonged time between IRB approval and enrollment of the first patient at participating sites (mean 19.6 ± 1.4 months); and (5) reorganization of clinical coordinating core infrastructure to align resources with enrollment. A Web-based anonymous survey of site investigators revealed site-related barriers to patient recruitment. The value of a variety of recruitment tools was of marginal utility in facilitating patient enrollment. We conclude that improvements in the logistics of study approval and regulatory start-up and testing of promising novel agents are important factors in promoting enrollment into randomized clinical trials in nephrology.

Differential microRNA expression tracks neoplastic progression in inflammatory bowel disease-associated colorectal cancer

One of the most serious complications faced by patients with inflammatory bowel disease (IBD) is the potential development of colorectal cancer (CRC). There is a compelling need to enhance the accuracy of cancer screening of IBD patients. MicroRNAs (miRNAs) are small nonprotein-coding RNAs that play important roles in CRC oncogenesis. In this study, we report differential miRNA expression in IBD patients with associated CRC from non-neoplastic tissue to dysplasia and eventually cancer. In addition, we identify and examine the role of dysregulated miRNAs in the TP53 pathway. In our CD patients, six miRNAs were upregulated from non-neoplastic tissue to dysplasia, but downregulated from dysplasia to cancer (miR-122, miR-181a, miR-146b-5p, let-7e, miR-17, miR-143) (P < 0.001). Six differentially expressed miRNAs affected the TP53 pathway (miR-122, miR-214, miR-372, miR-15b, let-7e, miR-17) (P < 0.001). Using two human colon cancer cell lines (HT-29 and HCT-116), E2F1, an upstream regulator of TP53, was downregulated in both cell lines transfected with let-7e (P < 0.05) as well as in HCT-116 cells transfected with miR-17 (P < 0.05). Additionally, cyclin G, a cell-cycle regulator miR-122 target was downregulated in both cell lines (P < 0.05). Unique differentially expressed miRNAs were observed in CD-associated CRC progression. Six of these miRNAs had a tumorigenic effect on the TP53 pathway; the effect of three of which was studied using cell lines.

Clinical research involving children: registration, completeness, and publication

BACKGROUND AND OBJECTIVE

Effective health care for children must be based on thorough analyses of the best research evidence. The objective of this study was to examine registration, completeness, and publication of studies involving children.

METHODS

We searched the ClinicalTrials.gov registry to identify all closed studies involving children and examined them for completeness and availability of results. We examined publication in peer-reviewed journals for 160 randomly selected National Institutes of Health (NIH)-funded studies from 2000 through 2010 and for 758 randomly selected completed studies.

RESULTS

Of 3428 closed studies involving children identified in ClinicalTrials.gov, 2385 (70%) were completed, 28 (0.8%) suspended, 152 (4.4%) terminated, and 38 (1.1%) withdrawn. The proportion of non-completed studies (terminated and suspended) increased linearly by 186% between 2001 and 2009, from 1.9% to 8.4%. Of the 152 terminated studies, 48 did not report reasons for termination, 21 cited safety concerns, and 83 cited poor recruitment or other administrative reasons. Only 29% of completed studies were published. Publication that did occur was an average of 2 years after study completion. Completed interventional studies were published more often than observational studies. Completed industry-funded studies were published less often than studies funded by the NIH. Registered NIH-funded trials were published more often than unregistered.

CONCLUSIONS

Results are unavailable for more than half of the studies involving children, revealing a substantial publication bias. Registration and posting of results on ClinicalTrials.gov should be mandatory for all studies involving children.

A novel approach for small sample size family-based association studies: sequential tests

In this paper, we propose a sequential probability ratio test (SPRT) to overcome the problem of limited samples in studies related to complex genetic diseases. The results of this novel approach are compared with the ones obtained from the traditional transmission disequilibrium test (TDT) on simulated data. Although TDT classifies single-nucleotide polymorphisms (SNPs) to only two groups (SNPs associated with the disease and the others), SPRT has the flexibility of assigning SNPs to a third group, that is, those for which we do not have enough evidence and should keep sampling. It is shown that SPRT results in smaller ratios of false positives and negatives, as well as better accuracy and sensitivity values for classifying SNPs when compared with TDT. By using SPRT, data with small sample size become usable for an accurate association analysis.

Small sample approach, and statistical and epidemiological aspects

In this chapter, the design of pharmacokinetic studies and phase III trials in children is discussed. Classical approaches and relatively novel approaches, which may be more useful in the context of drug research in children, are discussed. The burden of repeated blood sampling in pediatric pharmacokinetic studies may be overcome by the population pharmacokinetics approach using nonlinear mixed effect modeling as the statistical solution to sparse data. Indications and contraindications for phase III trials are discussed: only when there is true "equipoise" in the medical scientific community, it is ethical to conduct a randomized clinical trial. The many reasons why a pediatric trial may fail are illustrated with examples. Inadequate sample sizes lead to inconclusive results. Twelve classical strategies to minimize sample sizes are discussed followed by an introduction to group sequential design, boundaries design, and adaptive design. The evidence that these designs reduce sample sized between 35 and 70% is reviewed. The advantages and disadvantages of the different approaches are highlighted to give the reader a broad idea of the design types that can be considered. Finally, working with DMCs during the conduct of trials is introduced. The evidence regarding DMC activities, interim analysis results, and early termination of pediatric trials is presented. So far reporting is incomplete and heterogeneous, and users of trial reports may be misled by the results. A proposal for a checklist for the reporting of DMC issues, interim analyses, and early stopping is presented.

A systematic review of the reporting of Data Monitoring Committees' roles, interim analysis and early termination in pediatric clinical trials

Background

Decisions about interim analysis and early stopping of clinical trials, as based on recommendations of Data Monitoring Committees (DMCs), have far reaching consequences for the scientific validity and clinical impact of a trial. Our aim was to evaluate the frequency and quality of the reporting on DMC composition and roles, interim analysis and early termination in pediatric trials.

Methods

We conducted a systematic review of randomized controlled clinical trials published from 2005 to 2007 in a sample of four general and four pediatric journals. We used full-text databases to identify trials which reported on DMCs, interim analysis or early termination, and included children or adolescents. Information was extracted on general trial characteristics, risk of bias, and a set of parameters regarding DMC composition and roles, interim analysis and early termination.

Results

110 of the 648 pediatric trials in this sample (17%) reported on DMC or interim analysis or early stopping, and were included; 68 from general and 42 from pediatric journals. The presence of DMCs was reported in 89 of the 110 included trials (81%); 62 papers, including 46 of the 89 that reported on DMCs (52%), also presented information about interim analysis. No paper adequately reported all DMC parameters, and nine (15%) reported all interim analysis details. Of 32 trials which terminated early, 22 (69%) did not report predefined stopping guidelines and 15 (47%) did not provide information on statistical monitoring methods.

Conclusions

Reporting on DMC composition and roles, on interim analysis results and on early termination of pediatric trials is incomplete and heterogeneous. We propose a minimal set of reporting parameters that will allow the reader to assess the validity of trial results.

Patient involvement in health research: a contribution to a systematic review on the effectiveness of treatments for degenerative ataxias

This study aims to incorporate patients' perspective in the design of a systematic review of scientific literature on the effectiveness of degenerative ataxias (DA) treatments. 53 patients with DA from different regions of Spain were consulted using the Delphi method, with three rounds via e-mail. In the first round, obtained information was on treatments used and relevant self-perceived health problems related to DA. The following two rounds were used to prioritize and achieve a consensus on the answers. The participation rate was 100% for all rounds. The most relevant self-perceived health problems were limitations in activities of daily living (ADL), visual and auditory problems and diminished self-esteem. The bibliographic search for the systematic review was enriched by these patient contributions. No study offered information on treatment effectiveness for the following problems prioritized by patients: ADL, social relationships, disease acceptance and quality of life. Thus some of the self-perceived DA-related health problems identified by the patients have never been investigated and should be considered to improve future research projects which should be adapted to meet patients' needs. Effective participation of patients can extend the value of systematic reviews to ensure they respond to both clinicians' information needs and patients' expectations.

Pitfalls in the design and analysis of paediatric clinical trials: a case of a 'failed' multi-centre study, and potential solutions

Aim: To increase awareness of possible pitfalls in the design and analysis of a multi-centre randomized clinical trial and to give an overview of alternative study designs and their consequences for power analyses in case of limited availability of trial participants.

Methods: Investigation of the assumptions in the power calculation and re-analysis of the original data of a ‘failed’ trial on the effect of dexamethasone on the duration of mechanical ventilation in young children with respiratory syncytial virus infection. Use of ‘boundaries approach’ is explored using the data from this trial. A comprehensive overview of the various modern solutions for the design of a subsequent trial in this field is given.

Results: Two frequent major deficiencies of trial design and data analysis are reviewed in depth, i.e. too optimistic assumptions for the sample size calculation and failure to adjust for centre effects.

Conclusion: Critical review of trial assumptions and if necessary sample size recalculation based on an internal pilot by a data monitoring committee is recommended to maximize the probability of obtaining conclusive results.