Clinical trials in rare disease: challenges and opportunities

Quantitative Systems Pharmacology Models: Potential Tools for Advancing Drug Development for Rare Diseases

Rare diseases, affecting millions globally, present significant drug development challenges. This is due to the limited patient populations and the unique pathophysiology of these diseases, which can make traditional clinical trial designs unfeasible. Quantitative Systems Pharmacology (QSP) models offer a promising approach to expedite drug development, particularly in rare diseases. QSP models provide a mechanistic representation of the disease and drug response in virtual patients that can complement routinely applied empirical modeling and simulation approaches. QSP models can generate digital twins of actual patients and mechanistically simulate the disease progression of rare diseases, accounting for phenotypic heterogeneity. QSP models can also support drug development in various drug modalities, such as gene therapy. Impactful QSP models case studies are presented here to illustrate their value in supporting various aspects of drug development in rare indications. As these QSP model applications continue to mature, there is a growing possibility that they could be more widely integrated into routine drug development steps. This integration could provide a robust framework for addressing some of the inherent challenges in rare disease drug development.

A framework for N-of-1 trials of individualized gene-targeted therapies for genetic diseases

Individualized genetic therapies-medicines that precisely target a genetic variant that may only be found in a small number of individuals, as few as only one-offer promise for addressing unmet needs in genetic disease, but present unique challenges for trial design. By nature these new individualized medicines require testing in individualized N-of-1 trials. Here, we provide a framework for maintaining scientific rigor in N-of-1 trials. Building upon best practices from traditional clinical trial design, recent guidance from the United States Food and Drug Administration, and our own clinical research experience, we suggest key considerations including comprehensive baseline natural history, selection of appropriate clinical outcome assessments (COAs) individualized to the patient genotype-phenotype for safety and efficacy assessment over time, and specific statistical considerations. Standardization of N-of-1 trial designs in this fashion will maximize efficient learning from this next generation of targeted individualized therapeutics.

The state-of-the-art of N-of-1 therapies and the IRDiRC N-of-1 development roadmap

In recent years, a small number of people with rare diseases caused by unique genetic variants have been treated with therapies developed specifically for them. This pioneering field of genetic N-of-1 therapies is evolving rapidly, giving hope for the individualized treatment of people living with very rare diseases. In this Review, we outline the concept of N-of-1 individualized therapies, focusing on genetic therapies, and illustrate advances and challenges in the field using cases for which therapies have been successfully developed. We discuss why the traditional drug development and reimbursement pathway is not fit for purpose in this field, and outline the pragmatic, regulatory and ethical challenges this poses for future access to N-of-1 therapies. Finally, we provide a roadmap for N-of-1 individualized therapy development.

Advanced Regenerative Medicines for Rare Diseases: A Review of Industry Sponsors Investment Motivations

Despite regulatory changes designed to stimulate investment in therapies for rare diseases, many of these conditions lack government-approved treatments. Advanced regenerative medicines, which are therapies and clinical interventions aimed at healing or replacing damaged or defective human cells, tissues, and organs, offer great promise for addressing many rare diseases. A major challenge facing advanced regenerative medicines for rare diseases is securing financial support to assist in bringing a therapy to market. This paper describes the factors cited by pharmaceutical industry players globally for sponsoring the development of advanced regenerative medicines for rare diseases. The paper examines the motivations of 53 sponsors that meet the latter criteria. The motivations behind investments were broadly similar amongst sponsors and map closely onto regulatory requirements for clinical development and marketing authorization of advanced therapeutic products, including the presence of accelerated or attenuated pathways for regulatory approval, use for indications with high unmet medical needs, and/or that have advantages over existing therapies, and robust preclinical data. Other factors include availability of investment incentives and opportunities for off-label use in the post-approval stages.

Screen Failures in Clinical Trials in Retina

PURPOSE

Disparities in clinical trials are a major problem because of significant underrepresentation of certain gender, racial, and ethnic groups. Several factors including stringent eligibility criteria and recruitment strategies hinder our understanding of retinal disease. Thus, we aimed to study the various reasons of screen failures and specific patient and study characteristics among screen failures.

DESIGN

This is a cross-sectional retrospective study.

METHODS

Screening data of 87 trials from 6 centers were analyzed. Study characteristics (disease studied, phase of trial, and route of drug administration) and patient demographics (age, gender, race, ethnicity, and employment status) were compared among different causes of screen failures. Screen failures were broadly classified into 6 categories: exclusion because of vision-based criteria, exclusion because of imaging findings, exclusion because of other factors, patient-related criteria, physician-related criteria, and miscellaneous. Descriptive statistics, Pearson chi-square test, and analysis of variance were used for statistical analysis.

MAIN OUTCOME MEASURES

Prevalence of various reasons for screen failures in multiple trials and its trend among different study and patient characteristics.

RESULTS

Among 87 trials and 962 patients, 465 (48.2%) patients were successfully randomized and 497 (51.8%) patients were classified as screen failures. The trials were conducted for various retinal diseases. Mean age was 76.50 ± 10.45 years and 59.4% were females. Predominantly White patients (93.4%) and unemployed/retired patients (66.6%) were screened. Of the 497 screen failures, most were because of patients not meeting inclusion criteria of imaging findings (n = 221 [44.5%]) followed by inclusion of vision-based criteria (n = 73 [14.7%]), exclusion because of other factors (n = 75 [15.1%]), patient-related (n = 34 [6.8%]), physician-related (n = 28 [5.6%]), and miscellaneous reasons (n = 39 [7.8%]). Reason for screen failure was not available for 27 (5.4%) patients. A higher proportion of patients screened for surgical trials (15%) declined to participate in the study compared with noninvasive trials involving topical drugs and photobiomodulation (0%) (P = 0.02).

CONCLUSIONS

Patients not meeting the imaging and vision-cased criteria were the most common reasons for screen failures. White patients and unemployed patients predominantly participated in clinical trials. Patients are more inclined to continue participation in noninvasive clinical trials compared with surgical trials. Better recruitment strategies and careful consideration of study criteria can aid in decreasing the rate of screen failures.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references in the Footnotes and Disclosures at the end of this article.

CriteriaMapper: establishing the automatic identification of clinical trial cohorts from electronic health records by matching normalized eligibility criteria and patient clinical characteristics

The use of electronic health records (EHRs) holds the potential to enhance clinical trial activities. However, the identification of eligible patients within EHRs presents considerable challenges. We aimed to develop a CriteriaMapper system for phenotyping eligibility criteria, enabling the identification of patients from EHRs with clinical characteristics that match those criteria. We utilized clinical trial eligibility criteria and patient EHRs from the Mount Sinai Database. The CriteriaMapper system was developed to normalize the criteria using national standard terminologies and in-house databases, facilitating computability and queryability to bridge clinical trial criteria and EHRs. The system employed rule-based pattern recognition and manual annotation. Our system normalized 367 out of 640 unique eligibility criteria attributes, covering various medical conditions including non-small cell lung cancer, small cell lung cancer, prostate cancer, breast cancer, multiple myeloma, ulcerative colitis, Crohn's disease, non-alcoholic steatohepatitis, and sickle cell anemia. About 174 criteria were encoded with standard terminologies and 193 were normalized using the in-house reference tables. The agreement between automated and manual normalization was high (Cohen's Kappa = 0.82), and patient matching demonstrated a 0.94 F1 score. Our system has proven effective on EHRs from multiple institutions, showing broad applicability and promising improved clinical trial processes, leading to better patient selection, and enhanced clinical research outcomes.

Review of clinical trials and guidelines for children and youth with mucopolysaccharidosis: outcome selection and measurement

BACKGROUND

To inform the development of a core outcome set (COS) for children and youth with mucopolysaccharidoses (MPS), we aimed to identify all outcomes and associated outcome measurement instruments that are reported in recent clinical trials and recommended as measurements in clinical management guidelines.

METHODS

To identify English-language clinical trials and guidelines pertaining to MPS published between 2011 and mid-2021, we applied a comprehensive peer-reviewed search strategy to relevant databases and registers on May 16, 2021. Two reviewers independently screened retrieved citations and then full-text articles to determine eligibility for inclusion. From articles meeting inclusion criteria, we extracted details of the study design, population, intervention, and comparator, along with verbatim outcomes and associated outcome measurement instruments. Outcomes were organized into domains within five a priori core areas: life impact, pathophysiological manifestations, growth and development, resource use, and death. We conducted descriptive analyses at the study level, grouping articles arising from the same study.

RESULTS

From 2593 unique citations, 73 articles from 61 unique studies were included in the review, pertaining to all MPS subtypes except for exceptionally rare subtypes. Eighty-four unique outcomes were reported across the studies, 33 (39%) of which were reported by three or fewer studies. Most outcomes (55; 65%) were in the pathophysiological manifestations core area, followed by life impact (17; 20%) and growth and development (10; 12%); one outcome each pertained to resource use and death. The most frequently reported outcomes were general adverse events (45; 74%), immune-related adverse events (39; 64%), and urinary glycosaminoglycans (38; 62%). Substantial variability existed in the reporting of outcome measurement instruments. Some differences in outcome reporting were observed by MPS subtype and publication year.

DISCUSSION

Outcomes reported in clinical trials and guidelines for MPS in children and youth vary considerably and largely focus on pathophysiological manifestations. A COS is needed to standardize the selection and measurement of meaningful outcomes across future studies. We will present the outcomes identified in this review to knowledge users as part of a consensus process to select the most critical outcomes for inclusion in the COS. Trial Registration The protocol for this study was registered in PROSPERO (CRD42021267531) and in the COMET Database.

N-of-1 Studies in an Era of Precision Medicine

This JAMA Insights in the Genomics and Precision Health series examines N-of-1 trials, a term used to describe studies in small numbers of individuals or a single individual treated with genetically targeted interventions.

Anything is better than nothing': exploring attitudes towards novel therapies in leukodystrophy clinical trials

BACKGROUND/AIM

Leukodystrophies comprise a group of genetic white matter disorders that lead to progressive motor and cognitive impairment. Recent development of novel therapies has led to an increase in clinical trials for leukodystrophies. To enable recruitment of individuals with a leukodystrophy into clinical trials, clinical trial acceptability should be ascertained. We sought therefore, to identify the motivations for and barriers to clinical trial participation in addition to clinical trial features that may be of concern to individuals with a leukodystrophy and/or their carers.

METHODS

Adults with a leukodystrophy and parents/carers of individuals with a leukodystrophy were recruited through the Australian Leukodystrophy Registry and through online advertisements. Qualitative semi-structured interviews were used to explore participants views on what clinical trials involve, the perceived risks and benefits of clinical trials, their desire to participate in clinical trials and their personal experience with leukodystrophy. Thematic analysis of data was performed with co-coding of interview transcripts.

RESULTS

5 interviews were held with parents of children with leukodystrophy, 4 with parents of adults with leukodystrophy and 3 with adults diagnosed with leukodystrophy. Motivations for clinical trial enrolment include access to potentially lifesaving novel treatments and improved prognostic outcomes. Participants were concerned about adverse clinical trial outcomes, including side effects and exacerbation of illness. Despite this, majority of participants were willing to try anything in clinical trials, demonstrating a high tolerance for first in human trials and trials utilising invasive treatment options.

CONCLUSIONS

Interviewees communicated a strong desire to participate in interventional clinical trials involving novel therapies. To support enrolment into future leukodystrophy clinical trials we suggest the provision of transparent information regarding clinical trial treatments, consideration of alternative trial control measures, and inclusion of treating clinicians in the trial recruitment process. Clinicians play an integral role in initiating transparent conversations regarding trial risks and adverse outcomes.

[Formula: see text] Neuropsychological assessment in rare pediatric neurogenetic disorders: considerations for cross-cultural clinical research

Neuropsychological assessment in rare neurodevelopmental disorders has provided clinicians and researchers with a more comprehensive view of natural history as well as opportunities for additional endpoints in treatment trials. While challenges to protocol development have been addressed in the literature, cultural considerations have been overly broad resulting in limited utility when including mixed international samples. Using experiences over the past five years with the development of ten different protocols for neurogenetic rare diseases, this paper presents further considerations for protocol development that are culturally sensitive to international samples. Recommendations are offered across areas including participants from multiple countries; cognitive, sensory and motor impairments; psychometrics; and assessment logistics. A neuropsychological assessment selection checklist that guides researchers and clinicians through considerations and a standard operating procedure that provides guidance on thinking through the assessment process are offered.

Comparison of Demographics: National Amyotrophic Lateral Sclerosis Registry and Clinical Trials Data

OBJECTIVE

To characterize the participant demographics in the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database compared with the web-portal National Amyotrophic Lateral Sclerosis (ALS) Registry (the Registry).

METHODS

Demographics and ALS symptom information were compared between the self-reported registrant data in the Registry web portal (2010-2021) and the latest available PRO-ACT data (updated August 2022), which is a collection of clinical trials data.

RESULTS

Greater percentages of younger (≤ 59 years old) but smaller percentages of older (60 + years old) participants were represented in PRO-ACT compared to Registry. Enrollment for minority race groups was greater in the Registry portal data, but race information was largely missing/unknown in PRO-ACT database. Median age at the time of diagnosis and age at the time of symptom onset were significantly higher for Registry enrollees compared to the participants of PRO-ACT. Symptom onset sites were similarly reported, but duration between self-noted symptom onset and diagnosis was slight, but significantly longer for the Registry enrollees (11 vs. 9 months). Hispanic were as likely as non-Hispanic to participate in research studies, based on the Registry data.

CONCLUSION

There was a notable difference in the age distribution and minority representation of enrollees between the PRO-ACT and Registry study populations. Age distribution in the PRO-ACT database skewed to a younger and less diverse cohort. Despite the clinical heterogeneity and complex disease mechanism of ALS, identifying the underrepresented demographic niche in the PRO-ACT and Registry study populations can help improve patient participation and criteria for patient selection to enhance generalizability.

Unveiling the genetic tapestry: Rare disease genomics of spinal muscular atrophy and phenylketonuria proteins

Rare diseases, defined by their low prevalence, present significant challenges, including delayed detection, expensive treatments, and limited research. This study delves into the genetic basis of two noteworthy rare diseases in Saudi Arabia: Phenylketonuria (PKU) and Spinal Muscular Atrophy (SMA). PKU, resulting from mutations in the phenylalanine hydroxylase (PAH) gene, exhibits geographical variability and impacts intellectual abilities. SMA, characterized by motor neuron loss, is linked to mutations in the survival of motor neuron 1 (SMN1) gene. Recognizing the importance of unveiling signature genomics in rare diseases, we conducted a quantitative study on PAH and SMN1 proteins of multiple organisms by employing various quantitative techniques to assess genetic variations. The derived signature-genomics contributes to a deeper understanding of these critical genes, paving the way for enhanced diagnostics for disorders associated with PAH and SMN1.

Development of an Infantile GM2 Clinical Rating Scale: Remote Assessment of Clinically Meaningful Health-Related Function

GM2 gangliosidoses (GM2) are a group of rare lysosomal storage disorders in which accumulation of GM2 gangliosides results in progressive central nervous system damage. The infantile GM2 phenotype is characterized by delays in milestones by 6 months of age, followed by rapid loss of motor, cognitive, and visual function. Advancements in early diagnosis and pharmacotherapies provide promise for improved outcomes. However, the lack of feasible and clinically meaningful clinical outcome assessments for GM2 poses a challenge to characterizing GM2 natural history and selecting clinical trial endpoints. The purpose of this study was to develop a remotely administered infantile GM2 rating scale to measure health-related function in children with infantile GM2. A 2-phase mixed methods design was employed. In phase 1 of the study, 8 families of children with Infantile GM2 completed a natural history survey and a 1:1 semistructured interview to provide caregiver perspectives on the impacts of GM2 on health-related function. In phase 2 of the study, 8 expert clinicians provided feedback via surveys and participated in videoconference-hosted focus groups to refine scale administration and scoring procedures. These methods guided the development of 16 scale items to assess function in 5 health-related function domains: vision, hand and arm use, communication, gross motor, and feeding. This study used caregiver perspectives and expert clinician feedback to develop a remotely administered clinical outcome assessment of clinically meaningful health-related function in children with infantile GM2. Future studies will further evaluate the feasibility, reliability, and validity of the Infantile GM2 Clinical Rating Scale.

CRISPR-Based Gene Editing Techniques in Pediatric Neurological Disorders

The emergence of gene editing technologies offers a unique opportunity to develop mutation-specific treatments for pediatric neurological disorders. Gene editing systems can potentially alter disease trajectory by correcting dysfunctional mutations or therapeutically altering gene expression. Clustered regularly interspaced short palindromic repeats (CRISPR)-based approaches are attractive gene therapy platforms to personalize treatments because of their specificity, ease of design, versatility, and cost. However, many such approaches remain in the early stages of development, with ongoing efforts to optimize editing efficiency, minimize unintended off-target effects, and mitigate pathologic immune responses. Given the rapid evolution of CRISPR-based therapies, it is prudent for the clinically based child neurologist to have a conceptual understanding of what such therapies may entail, including both benefits and risks and how such therapies may be clinically applied. In this review, we describe the fundamentals of CRISPR-based therapies, discuss the opportunities and challenges that have arisen, and highlight preclinical work in several pediatric neurological diseases.

A systematic review of real-world evidence (RWE) supportive of new drug and biologic license application approvals in rare diseases

BACKGROUND

Real-world evidence (RWE) generated using real-world data (RWD) presents the potential to contextualize and/or supplement traditional clinical trials for regulatory approval of rare diseases (RDs). This systematic review evaluated the use of RWD for non-oncologic RD therapies with orphan drug designation (ODD) to support efficacy outcomes in regulatory application packages to the US Food and Drug Administration (FDA). New drug applications (NDAs) and biologic license applications (BLAs) submitted between January 2017 and October 2022 were obtained from publicly available FDA drug approval websites. NDAs and BLAs of non-oncologic RD therapies were screened, and manually reviewed using RWE-related keywords. Quantitative summary of number/proportion of study types was provided, whereas qualitative synthesis focused on key categories of output assessing the use of RWD in overall drug approval process, including agency's feedback on its strengths and key challenges.

RESULTS

A total of 868 NDAs and BLAs were identified, of which 243 were screened for non-oncologic RDs with ODD, and 151 were subsequently reviewed for the RWD used to support efficacy outcomes. Twenty (12 NDAs, 8 BLAs) applications met the review inclusion criteria. Most (19; 95%) applications used only retrospective RWD, while one (5%) collected RWD both retrospectively and prospectively. RWD studies included natural history including registry-based/retrospective historical controls (14; 70%), retrospective medical chart-reviews (4; 20%), and external RWD controls from other studies (2; 10%). The FDA generally accepted RWD studies demonstrating a large effect size despite the noted concerns and criticisms. However, the agency expressed concerns about overall quality and comparability of RWD with trial data for some applications, including RWD study designs with respect to differences in patients' baseline characteristics, missing information, and potential bias and measurement errors.

CONCLUSIONS

This systematic review highlights potential benefits of appropriately conducted RWE studies in RD, which can strengthen the clinical evidence for efficacy comparison and contextualization to support product approval efforts, particularly when a large magnitude of effect is observed for the new intervention. Nonetheless, quality and completeness of RWD and its comparability with trial data remain areas of concern that can serve as valuable learnings for advancing future science and regulatory approvals.

Recommendations for the collection and annotation of biosamples for analysis of biomarkers in neurofibromatosis and schwannomatosis clinical trials

INTRODUCTION

Neurofibromatosis 1 and schwannomatosis are characterized by potential lifelong morbidity and life-threatening complications. To date, however, diagnostic and predictive biomarkers are an unmet need in this patient population. The inclusion of biomarker discovery correlatives in neurofibromatosis 1/schwannomatosis clinical trials enables study of low-incidence disease. The implementation of a common data model would further enhance biomarker discovery by enabling effective concatenation of data from multiple studies.

METHODS

The Response Evaluation in Neurofibromatosis and Schwannomatosis biomarker working group reviewed published data on emerging trends in neurofibromatosis 1 and schwannomatosis biomarker research and developed recommendations in a series of consensus meetings.

RESULTS

Liquid biopsy has emerged as a promising assay for neurofibromatosis 1/schwannomatosis biomarker discovery and validation. In addition, we review recommendations for a range of biomarkers in clinical trials, neurofibromatosis 1/schwannomatosis-specific data annotations, and common data models for data integration.

CONCLUSION

These Response Evaluation in Neurofibromatosis and Schwannomatosis consensus guidelines are intended to provide best practices for the inclusion of biomarker studies in neurofibromatosis 1/schwannomatosis clinical trials, data, and sample annotation and to lay a framework for data harmonization and concatenation between trials.

Understanding dentatorubral-pallidoluysian atrophy (DRPLA) symptoms and impacts on daily life: a qualitative interview study with patients and caregivers

Background

Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare, neurodegenerative disorder with no disease-modifying treatments. There is a dearth of information in the literature about the patient and caregiver experience living with DRPLA.

Objectives

This study aimed to (1) understand symptoms experienced by adult- and juvenile-onset DRPLA populations and their impact on daily life and (2) explore patient and caregiver treatment goals and clinical trial participation preferences.

Design

The study was a qualitative interview study.

Methods

Interviews were conducted remotely with adult patients with DRPLA and caregivers. Participants described patient symptoms and the impact of those symptoms on daily life, and they discussed treatment goals and potential clinical trial participation. There were 18 patients described in the interviews with two patients and seven caregivers. Some participants were caregivers to multiple patients with DRPLA.

Results

Interview transcripts were coded for themes, and reported symptoms were summarized with descriptive statistics. Adult-onset patients (N = 7) experienced difficulty with ataxia (100%), cognition (100%), fine motor skills (100%), gross motor skills (100%), speech (100%), personality changes (100%), and seizures (57%). Juvenile-onset patients (N = 11) experienced difficulty with ataxia (100%), sleep (100%), speech (100%), jerking/twitching (83%), behavior (82%), cognition (82%), fine motor skills (82%), gross motor skills (82%), sensory sensitivity (75%), and seizures (64%). When considering aspects of DRPLA to target for future treatment, patients prioritized ataxia/mobility (100%), juvenile-onset caregivers prioritized ataxia/mobility (60%) and independence (60%), and adult-onset caregivers prioritized personality (60%). Almost all patients (93%) would participate in a clinical trial if given the opportunity, but travel to a clinical site could pose a participation barrier for half.

Conclusion

This study found that there are symptom domains that are relevant across the DRPLA population, but there is heterogeneity within each domain based on the age of symptom onset and disease stage, which has implications for clinical trial design.

Current rehabilitation practice for the evaluation and treatment of children with arthrogryposis: an international survey

PURPOSE

To describe the current practices in rehabilitation for the evaluation and treatment of children with arthrogryposis multiplex congenita (AMC).

MATERIALS AND METHODS

Rehabilitation practitioners worldwide with at least 2 years of experience with AMC were invited to complete an electronic survey on the evaluations and treatments used with children with AMC within five areas: muscle and joint function, self-care, mobility, pain, participation and psychosocial wellbeing.

RESULTS

Sixty five participants from nine countries completed the survey. Participants completed the sections applicable to their practice. Number of participants within each area varied between 24 and 53. Over 80% of participants used non-standardized evaluations across areas while <50% used patient-reported or standardized measures. Stretching of upper and lower limbs was reported by >80% across ages and clinical presentation severity. Strengthening reported by >70% was mainly used among children >3 years old with less severe contractures. Other interventions used across areas included orthotics (>70%), positioning (>80%), activity-based training (>80%), assistive devices for self-care (>50%) and mobility (>80%), and energy conservation (>70%). Over 70% of participants were involved in perioperative rehabilitation.

CONCLUSION

Knowledge of current pediatric rehabilitation practice in AMC, together with empirical evidence, may guide clinical decision-making and identify avenues for future research.

Linking Angelman and dup15q data for expanded research (LADDER) database: a model for advancing research, clinical guidance, and therapeutic development for rare conditions

Angelman syndrome (AS) and duplication 15q (dup15q) syndrome are rare neurogenetic conditions arising from a common locus on the long arm of chromosome 15. Individuals with both conditions share some clinical features (e.g. intellectual disability, epilepsy) and often require lifelong care. Disease-modifying therapies for both conditions are emerging, resulting in a significant need for a better understanding of the natural history of both AS and dup15q. Patient advocacy groups for both conditions recognized a need for a data repository that would link data on individuals from multiple sources to expand research, increase understanding of natural history, and accelerate the development of treatments, resulting in the Linking Angelman and Dup15q Data for Expanded Research (LADDER) Database. This paper describes the development and functionality of the LADDER Database - including challenges, lessons learned, and preliminary feasibility - and how it can be used as a model for other rare conditions.

WiTNNess: An international natural history study of infantile-onset TNNT1 myopathy

OBJECTIVE

We created WiTNNess as a hybrid prospective/cross-sectional observational study to simulate a clinical trial for infantile-onset TNNT1 myopathy. Our aims were to identify populations for future trial enrollment, rehearse outcome assessments, specify endpoints, and refine trial logistics.

METHODS

Eligible participants had biallelic pathogenic variants of TNNT1 and infantile-onset proximal weakness without confounding conditions. The primary endpoint was ventilator-free survival. "Thriving" was a secondary endpoint defined as the ability to swallow and grow normally without non-oral feeding support. Endpoints of gross motor function included independent sitting and standing as defined by the Word Health Organization, a novel TNNT1 abbreviated motor score, and video mapping of limb movement. We recorded adverse events, concomitant medications, and indices of organ function to serve as comparators of safety in future trials.

RESULTS

Sixteen children were enrolled in the aggregate cohort (6 prospective, 10 cross-sectional; median census age 2.3 years, range 0.5-13.8). Median ventilator-free survival was 20.2 months and probability of death or permanent mechanical ventilation was 100% by age 60 months. All six children (100%) in the prospective arm failed to thrive by age 12 months. Only 2 of 16 (13%) children in the aggregate cohort sat independently and none stood alone. Novel exploratory motor assessments also proved informative. Laboratory and imaging data suggest that primary manifestations of TNNT1 deficiency are restricted to skeletal muscle.

INTERPRETATION

WiTNNess allowed us to streamline and economize the collection of historical control data without compromising scientific rigor, and thereby establish a sound operational framework for future clinical trials.

Digital measures of respiratory and upper limb function in spinal muscular atrophy: design, feasibility, reliability, and preliminary validity of a smartphone sensor-based assessment suite

Spinal muscular atrophy (SMA) is characterized by progressive muscle weakness and paralysis. Motor function is monitored in the clinical setting using assessments including the 32-item Motor Function Measure (MFM-32), but changes in disease severity between clinical visits may be missed. Digital health technologies may assist evaluation of disease severity by bridging gaps between clinical visits. We developed a smartphone sensor-based assessment suite, comprising nine tasks, to assess motor and muscle function in people with SMA. We used data from the risdiplam phase 2 JEWELFISH trial to assess the test-retest reliability and convergent validity of each task. In the first 6 weeks, 116 eligible participants completed assessments on a median of 6.3 days per week. Eight of the nine tasks demonstrated good or excellent test-retest reliability (intraclass correlation coefficients >0.75 and >0.9, respectively). Seven tasks showed a significant association (P < 0.05) with related clinical measures of motor function (individual items from the MFM-32 or Revised Upper Limb Module scales) and seven showed significant association (P < 0.05) with disease severity measured using the MFM-32 total score. This cross-sectional study supports the feasibility, reliability, and validity of using smartphone-based digital assessments to measure function in people living with SMA.

Critical path activities in clinical trial setup and conduct: How to avoid bottlenecks and accelerate clinical trials

Most clinical trials are delayed due to scientific and/or operational challenges. Any effort to minimize delays can generate value for patients and sponsors. This article reviews critical path process steps commonly identified by practitioners, such as during protocol development, site contracting, or patient recruitment. Commonly considered measures, such as adding more trial sites or countries, were contrasted with less frequented measures, such as evidence-based feasibility or real-world evidence analysis, to help validate assumptions before clinical trial initiation. In a broad analysis, we integrated a literature review with a practitioner survey into a framework to help decision makers on the most critical process steps when setting up or conducting clinical trials in order to bring critical treatments to patients faster.

Pharmacovigilance for rare diseases: a bibliometrics and knowledge-map analysis based on web of science

OBJECTIVES

The aims of this paper is to search and explore publications in the field of pharmacovigilance for rare diseases and to visualize general information, research hotspots, frontiers and future trends in the field using the bibliometric tool CiteSpace to provide evidence-based evidence for scholars.

METHODS

We searched the Web of Science Core Collection (WoSCC) for studies related to pharmacovigilance for rare diseases, spanning January 1, 1997-October 25, 2022. CiteSpace software was utilized to discuss countries/regions, institutions, authors, journals, and keywords.

RESULTS

After screening, a total of 599 valid publications were included in this study, with a significant upward trend in the number of publications. These studies were from 68 countries/regions with the United States and the United Kingdom making the largest contributions to the field. 4,806 research scholars from 493 institutions conducted studies on pharmacovigilance for rare diseases. Harvard University and University of California were the top two productive institutions in the research field. He Dian of the Affiliated Hospital of Guizhou Medical University and Peter G.M. Mol of the University of Groningen, The Netherlands, were the two most prolific researchers. The Cochrane Database of Systematic Reviews and the New England Journal of Medicine were the journals with the highest number of articles and co-citation frequency respectively. Clinical trial, therapy and adverse event were the top three most cited keywords.

CONCLUSIONS

Based on keywords co-occurrence analysis, four research topics were identified: orphan drug clinical trials, postmarketing ADR surveillance for orphan drugs, rare diseases and orphan drug management, and diagnosis and treatment of rare diseases. Immune-related adverse reactions and benefit-risk assessment of enzyme replacement therapy were at the forefront of research in this field. Treatment outcomes, early diagnosis and natural history studies of rare diseases may become hotspots for future research.

Uncovering key clinical trial features influencing recruitment

Background

Randomized clinical trials (RCT) are the foundation for medical advances, but participant recruitment remains a persistent barrier to their success. This retrospective data analysis aims to (1) identify clinical trial features associated with successful participant recruitment measured by accrual percentage and (2) compare the characteristics of the RCTs by assessing the most and least successful recruitment, which are indicated by varying thresholds of accrual percentage such as ≥ 90% vs ≤ 10%, ≥ 80% vs ≤ 20%, and ≥ 70% vs ≤ 30%.

Methods

Data from the internal research registry at Columbia University Irving Medical Center and Aggregated Analysis of ClinicalTrials.gov were collected for 393 randomized interventional treatment studies closed to further enrollment. We compared two regularized linear regression and six tree-based machine learning models for accrual percentage (i.e., reported accrual to date divided by the target accrual) prediction. The outperforming model and Tree SHapley Additive exPlanations were used for feature importance analysis for participant recruitment. The identified features were compared between the two subgroups.

Results

CatBoost regressor outperformed the others. Key features positively associated with recruitment success, as measured by accrual percentage, include government funding and compensation. Meanwhile, cancer research and non-conventional recruitment methods (e.g., websites) are negatively associated with recruitment success. Statistically significant subgroup differences (corrected p-value < .05) were found in 15 of the top 30 most important features.

Conclusion

This multi-source retrospective study highlighted key features influencing RCT participant recruitment, offering actionable steps for improvement, including flexible recruitment infrastructure and appropriate participant compensation.

Quantitative Systems Pharmacology for Rare Disease Drug Development

Though hundreds of drugs have been approved by the US Food and Drug Administration (FDA) for treating various rare diseases, most rare diseases still lack FDA-approved therapeutics. To identify the opportunities for developing therapies for these diseases, the challenges of demonstrating the efficacy and safety of a drug for treating a rare disease are highlighted herein. Quantitative systems pharmacology (QSP) has increasingly been used to inform drug development; our analysis of QSP submissions received by FDA showed that there were 121 submissions as of 2022, for informing rare disease drug development across development phases and therapeutic areas. Examples of published models for inborn errors of metabolism, non-malignant hematological disorders, and hematological malignancies were briefly reviewed to shed light on use of QSP in drug discovery and development for rare diseases. Advances in biomedical research and computational technologies can potentially enable QSP simulation of the natural history of a rare disease in the context of its clinical presentation and genetic heterogeneity. With this function, QSP may be used to conduct in-silico trials to overcome some of the challenges in rare disease drug development. QSP may play an increasingly important role in facilitating development of safe and effective drugs for treating rare diseases with unmet medical needs.

Designs used in published therapeutic studies of rare superficial vascular anomalies: a systematic literature search

BACKGROUND

Rare superficial vascular anomalies represent a wide range of diseases. Their management is difficult given the broad spectrum and the lack of clinical trials assessing treatment efficacy. A randomized clinical trial of vascular anomalies is difficult because of the rarity of the diseases and is enhanced by the population of interest often being children. Therefore, suitable designs are needed. We conducted a methodological systematic literature search to identify designs implemented for investigating the treatment of rare superficial vascular anomalies.

METHODS

We conducted a literature search on January 25, 2021, of the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, ClinicalTrials.gov and European Union Clinical Trials Register databases. This systematic methodological literature search was registered at the Prospective Register of Systematic Reviews (PROSPERO: CRD42021232449). Randomized and non-randomized studies were included if they met the following criteria: were prospective studies of rare superficial vascular anomaly therapies, dealt with humans (adults and children) and were published in English from 2000. We excluded case reports/case series reporting fewer than 10 patients, reviews, retrospective studies, animal studies, studies of systemic or common vascular anomalies and non-therapeutic studies. We did not assess risk of bias in the included studies because our review was a methodological one focused on the design used. The review provided a descriptive analysis of relevant features of eligible research studies.

RESULTS

From 2046 articles identified, we included 97 studies (62 reports and 35 ongoing studies): 25 randomized controlled studies, 7 non-randomized comparative studies, 64 prospective cohorts and 1 case series. Among the 32 comparative studies included, 21 used a parallel-group design. The 11 other studies used different designs such as cross-over, randomized placebo phase, delayed-start, within-person, or challenge-dechallenge-rechallenge or used a historical control group or an observational run-in period.

CONCLUSIONS

Our systematic literature search highlights the lack of randomized control trials in superficial vascular anomalies due to the rarity of patients and their heterogeneity. New designs are emerging and can overcome the limitations of testing treatments in parallel groups.

Challenges and strategies for clinical trials in propionic and methylmalonic acidemias

Clinical trial development in rare diseases poses significant study design and methodology challenges, such as disease heterogeneity and appropriate patient selection, identification and selection of key endpoints, decisions on study duration, choice of control groups, selection of appropriate statistical analyses, and patient recruitment. Therapeutic development in organic acidemias (OAs) shares many challenges with other inborn errors of metabolism, such as incomplete understanding of natural history, heterogenous disease presentations, requirement for sensitive outcome measures and difficulties recruiting a small sample of participants. Here, we review strategies for the successful development of a clinical trial to evaluate treatment response in propionic and methylmalonic acidemias. Specifically, we discuss crucial decisions that may significantly impact success of the study, including patient selection, identification and selection of endpoints, determination of the study duration, consideration of control groups including natural history controls, and selection of appropriate statistical analyses. The significant challenges associated with designing a clinical trial in rare disease can sometimes be successfully met through strategic engagement with experts in the rare disease, seeking regulatory and biostatistical guidance, and early involvement of patients and families.

Efficacy and safety of vigabatrin in patients with tuberous sclerosis complex and infantile epileptic spasm syndrome: a systematic review

INTRODUCTION

Tuberous sclerosis complex (TSC) is a common genetic cause of epilepsy. Infantile epileptic spasm syndrome (IESS) is often the presenting neurologic feature, progressively evolving into refractory epilepsy. Vigabatrin (VGB) is often used in clinical practice as a first-line therapy in TSC with IESS. This systematic review aims to collect and analyze the efficacy data about VGB in TSC cases with IESS, in order to evaluate the strength of evidence in the literature.

METHODS

A systematic search of trials, observational studies, and case series involving patients with TSC and IESS treated with VGB was performed using MEDLINE, CENTRAL, and the US NIH Clinical Trials Registry. Single case studies, animal and non-English language studies were excluded. Seventeen studies were selected, of which 3 were RCTs and 14 were observational studies.

RESULTS

An overall response rate of 67% (231/343 responders) resulted from the analysis, with a spasm-free rate restricted to RCTs of 88% (29/33 subjects).

CONCLUSIONS

Although all the studies analyzed reported beneficial effects of VGB in TSC patients with IESS, with higher response rates in comparison to non-TSC subjects with IESS, a low level of evidence and high heterogeneity do not guarantee sufficient strength for therapeutic recommendations.

Paper II: thematic framework analysis of registry-based randomized controlled trials provided insights for designing trial ready registries

OBJECTIVES

Registry-based randomized controlled trials (RRCTs) are increasingly used, promising to address challenges associated with traditional randomized controlled trials. We identified strengths and limitations reported in planned and completed RRCTs to inform future RRCTs.

STUDY DESIGN AND SETTING

We conducted an environmental scan of literature discussing conceptual or methodological strengths and limitations of using registries for trial design and conduct (n = 12), followed by an analysis of RRCT protocols (n = 13) and reports (n = 77) identified from a scoping review. Using framework analysis, we developed and refined a conceptual framework of RRCT-specific strengths and limitations. We mapped and interpreted strengths and limitations discussed by authors of RRCT articles using framework codes and quantified the frequencies at which these were mentioned.

RESULTS

Our conceptual framework identified six main RRCT strengths and four main RRCT limitations. Considering implications for RRCT conduct and design, we formulated ten recommendations for registry designers, administrators, and trialists planning future RRCTs.

CONCLUSION

Consideration and application of empirically underpinned recommendations for future registry design and trial conduct may help trialists utilize registries and RRCTs to their full potential.

The temporal trend of placebo response in migraine prevention from 1990 to 2021: a systematic literature review and meta-analysis with regression

BACKGROUND

Migraine affects 1.1 billion people globally and is the second leading cause of disability worldwide. In clinical trials, treatment efficacy is evaluated by comparing the differential responses in the treatment and placebo arms. Although placebo response in preventive migraine trials has been studied, there is limited research examining temporal trends. This study evaluates the trend of placebo response over thirty years in migraine prevention trials and investigates the association of potential confounders, such as patient, treatment, and study characteristics on placebo response using meta-analysis with regression.

METHODS

We conducted literature searches from January 1990 to August 2021 in bibliographical databases (PubMed, Cochrane Library, and EMBASE). Studies were selected according to PICOS criteria and included randomized, double-blind, placebo-controlled trials evaluating preventive migraine treatments in adult patients diagnosed with episodic or chronic migraine, with or without aura. The protocol was registered with PROSPERO (CRD42021271732). Migraine efficacy outcomes included were either continuous (e.g., monthly migraine days) or dichotomous (e.g., ≥ 50% responder rate (yes/no)). We assessed the correlation of the change in outcome from baseline in the placebo arm, with the year of publication. The relationship between placebo response and year of publication was also assessed after accounting to confounders.

RESULTS

A total of 907 studies were identified, and 83 were found eligible. For the continuous outcomes, the change from baseline in mean placebo response showed an increase over the years (rho = 0.32, p = 0.006). The multivariable regression analysis also showed an overall increase in placebo response over the years. The correlation analysis of dichotomous responses showed no significant linear trend between publication year and mean placebo response (rho = 0.08, p = 0.596). Placebo response also varied by route of administration.

CONCLUSION

Placebo response increased over the past 30 years in migraine preventive trials. This phenomenon should be considered when designing clinical trials and conducting meta-analyses.

Novel Generative Recurrent Neural Network Framework to Produce Accurate, Applicable, and Deidentified Synthetic Medical Data for Patients With Metastatic Cancer

PURPOSE

Sensitive patient data cannot be easily shared/analyzed, severely limiting the innovative progress of research, specifically for marginalized/under-represented populations. Existing methods of deidentification are subject to data breaches. The objective of this study was to develop a neural network capable of generating a synthetic version of data for patients with novel postoperative metastatic cancer.

METHODS

We analyzed a metastatic cancer patient cohort of 167,474 patients obtained from the National Surgical Quality Improvement Program. Twenty-seven clinical features were analyzed. We created a volume-matched synthetic cohort of 167,474 patients and a reduced-size synthetic cohort of 5,000 patients. The volume-matched and reduced-size synthetic cohorts were compared against the ground truth data to analyze differences in principal component distribution, underlying statistical properties/associations, intervariable correlations, and machine learning classifier performance when developed on the synthetic data.

RESULTS

Among 167,474 patients with metastatic cancer in the original data, 50,669 (30.3%) died within 30 days of their index surgery. Our model was able to accurately capture underlying statistical properties, principal components, and intervariable correlations within the ground truth data, yielding an accuracy of 93.2% with a loss of 0.21%, and develop synthetic data capable of training accurate machine learning classifiers. The reduced-size synthetic data accurately replicated all categorical variables and every continuous variable with statistically similar records (P > .05), with the sole exception of preoperative albumin (P < .05). The volume-matched synthetic data frame was able to accurately replicate all categorical variables (P > .05).

CONCLUSION

This described methodology can be applied to any structured medical data from any setting, significantly expedite scientific analysis/innovation, and be used to develop improved predictive classifiers with boosted tree-based algorithms, serving as the potential new gold standard of medical data sharing and data augmentation.

Systematic analysis of levels of evidence supporting American Academy of Ophthalmology Preferred Practice Pattern guidelines, 2012-2021

BACKGROUND

Despite the increased emphasis on evidence-based medicine, the current state of evidence behind ophthalmology clinical practice guidelines is unknown. The purpose of this systematic analysis was to understand the levels of evidence (LOE) supporting American Academy of Ophthalmology (AAO) Preferred Practice Pattern (PPP) guidelines, assess changes over time, and compare LOE across ophthalmology subspecialties.

METHODS

All current PPP guidelines and their immediate predecessors were comprehensively reviewed to identify all recommendations with LOE provided (I [randomized controlled trials], II [case-control or cohort studies], and III [nonanalytic studies]).

RESULTS

Twenty-three out of 24 current PPPs had a prior edition. Among the PPPs with a prior edition, the number of recommendations with LOE decreased from 1254 in prior PPPs to 94 in current PPPs. The number of recommendations with LOE I decreased from 114 to 83, LOE II decreased from 147 to 2, and LOE III decreased from 993 to 9. However, the proportion of LOE I recommendations increased from 9 to 88%, driven by a disproportionate decrease in reporting of evidence lower than LOE I. Subgroup analysis by subspecialty showed similar trends (LOE I recommendations in prior PPPs vs current PPPs: retina: 57 [12%] vs 19 [100%]; cornea: 33 [5%] vs 24 [100%]; glaucoma: 9 [23%] vs 17 [100%]; cataract: 13 [17%] vs 18 [100%]).

CONCLUSIONS

Trends in LOE reporting in PPP guidelines indicate an increasing emphasis on evidence from randomized controlled trials from 2012 to 2021. The decline in the number of recommendations with LOE reported suggests an area for improvement in future guidelines as the presence of LOE is crucial to facilitate interpretation of clinical practice guidelines.

Study design challenges and strategies in clinical trials for rare diseases: Lessons learned from pantothenate kinase-associated neurodegeneration

Substantial challenges in study design and methodology exist during clinical trial development to examine treatment response in patients with a rare disease, especially those with predominant central nervous system involvement and heterogeneity in clinical manifestations and natural history. Here we discuss crucial decisions which may significantly impact success of the study, including patient selection and recruitment, identification and selection of endpoints, determination of the study duration, consideration of control groups including natural history controls, and selection of appropriate statistical analyses. We review strategies for the successful development of a clinical trial to evaluate treatment of a rare disease with a focus on inborn errors of metabolism (IEMs) that present with movement disorders. The strategies presented using pantothenate kinase-associated neurodegeneration (PKAN) as the rare disease example can be applied to other rare diseases, particularly IEMs with movement disorders (e.g., other neurodegeneration with brain iron accumulation disorders, lysosomal storage disorders). The significant challenges associated with designing a clinical trial in rare disease can sometimes be successfully met through strategic engagement with experts in the rare disease, seeking regulatory and biostatistical guidance, and early involvement of patients and families. In addition to these strategies, we discuss the urgent need for a paradigm shift within the regulatory processes to help accelerate medical product development and bring new innovations and advances to patients with rare neurodegenerative diseases who need them earlier in disease progression and prior to clinical manifestations.

Detecting impaired muscle relaxation in myopathies with the use of motor cortical stimulation

Impaired muscle relaxation is a notable feature in specific myopathies. Transcranial magnetic stimulation (TMS) of the motor cortex can induce muscle relaxation by abruptly halting corticospinal drive. Our aim was to quantify muscle relaxation using TMS in different myopathies with symptoms of muscle stiffness, contractures/cramps, and myalgia and explore the technique's diagnostic potential. In men, normalized peak relaxation rate was lower in Brody disease (n = 4) (-3.5 ± 1.3 s^-1), nemaline myopathy type 6 (NEM6; n = 5) (-7.5 ± 1.0 s^-1), and myotonic dystrophy type 2 (DM2; n = 5) (-10.2 ± 2.0 s^-1) compared to healthy (n = 14) (-13.7 ± 2.1 s^-1; all P ≤ 0.01) and symptomatic controls (n = 9) (-13.7 ± 1.6 s^-1; all P ≤ 0.02). In women, NEM6 (n = 5) (-5.7 ± 2.1 s^-1) and McArdle patients (n = 4) (-6.6 ± 1.4 s^-1) had lower relaxation rate compared to healthy (n = 10) (-11.7 ± 1.6 s^-1; both P ≤ 0.002) and symptomatic controls (n = 8) (-11.3 ± 1.8 s^-1; both P ≤ 0.008). TMS-induced muscle relaxation achieved a high level of diagnostic accuracy (area under the curve = 0.94 (M) and 0.92 (F)) to differentiate symptomatic controls from myopathy patients. Muscle relaxation assessed using TMS has the potential to serve as a diagnostic tool, an in-vivo functional test to confirm the pathogenicity of unknown variants, an outcome measure in clinical trials, and monitor disease progression.

Enzyme replacement therapy for children with acid sphingomyelinase deficiency in the real world: A single center experience in Taiwan

Background

Acid sphingomyelinase deficiency (ASMD) is a lysosomal storage disease with multi-systemic involvement, with no disease-modifying treatment available. Olipudase alfa is an investigational enzyme product developed to replace the deficient acid sphingomyelinase in ASMD patients. Several clinical trials have reported promising safety and efficacy results in adult and pediatric patients. However, no data have been reported outside of the clinical trial setting yet. This study aimed to evaluate major outcomes in pediatric chronic ASMD patients receiving olipudase alfa in the real-world setting.

Materials and methods

Two children with type A/B (chronic neuropathic) ASMD have received olipudase alfa treatment since May 2021. Clinical parameters, including height, weight, complete blood count, liver function tests, lipid profiles, biomarkers, abdominal ultrasonography with shear wave elastography, chest computed tomography, nerve conduction studies, neurodevelopmental evaluations, and six-minute walk tests, were checked at baseline and every three to six months in the first year of enzyme replacement therapy (ERT) to assess its efficacy and safety.

Results

The two patients in our study started olipudase alfa treatment at the age of 5 years and 8 months and 2 years and 6 months. During the first year of treatment, both patients saw a reduction in their hepatic and splenic volumes as well as liver stiffness. Height z-score, weight z-score, lipid profiles, biomarker levels, interstitial lung disease scores, and bone mineral densities also improved over time. The six-minute walk test showed a gradual increase in walking distance in both patients. There were no obvious improvements or deterioration in neurocognitive function and peripheral nerve conduction velocities after treatment. No severe infusion-associated reactions were noted during the first year of treatment. One patient had two episodes of transient but significantly elevated liver enzymes during the dose-escalation phase. The patient was asymptomatic, and the impaired liver function resolved spontaneously within two weeks.

Conclusion

Our results provide real-world experience that olipudase alfa is safe and effective in improving major systemic clinical outcomes for pediatric chronic ASMD patients. Monitoring of liver stiffness by shear wave elastography is a noninvasive procedure that can monitor treatment efficacy during ERT.

Toward representative genomic research: the children's rare disease cohorts experience

Background

Due to racial, cultural, and linguistic marginalization, some populations experience disproportionate barriers to genetic testing in both clinical and research settings. It is difficult to track such disparities due to non-inclusive self-reported race and ethnicity categories within the electronic health record (EHR). Inclusion and access for all populations is critical to achieve health equity and to capture the full spectrum of rare genetic disease.

Objective

We aimed to create revised race and ethnicity categories. Additionally, we identified racial and ethnic under-representation amongst three cohorts: (1) the general Boston Children's Hospital patient population (general BCH), (2) the BCH patient population that underwent clinical genomic testing (clinical sequencing), and (3) Children's Rare Disease Cohort (CRDC) research initiative participants.

Design and Methods

Race and ethnicity data were collected from the EHRs of the general BCH, clinical sequencing, and CRDC cohorts. We constructed a single comprehensive set of race and ethnicity categories. EHR-based race and ethnicity variables were mapped within each cohort to the revised categories. Then, the numbers of patients within each revised race and ethnicity category were compared across cohorts.

Results

There was a significantly lower percentage of Black or African American/African, non-Hispanic/non-Latine individuals in the CRDC cohort compared with the general BCH cohort, but there was no statistically significant difference between the CRDC and the clinical sequencing cohorts. There was a significantly lower percentage of multi-racial, Hispanic/Latine individuals in the CRDC cohort than the clinical sequencing cohort. White, non-Hispanic/non-Latine individuals were over-represented in the CRDC compared to the two other groups.

Conclusion

We highlight underrepresentation of certain racial and ethnic populations in sequencing cohorts compared to the general hospital population. We propose a range of measures to address these disparities, to strive for equitable future precision medicine-based clinical care and for the benefit of the whole rare disease community.

Efficacy and safety of setmelanotide, a melanocortin-4 receptor agonist, in patients with Bardet-Biedl syndrome and Alström syndrome: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial with an open-label period

BACKGROUND

Impaired cilial signalling in the melanocortin-4 receptor (MC4R) pathway might contribute to obesity in patients with Bardet-Biedl syndrome and Alström syndrome, rare genetic diseases associated with hyperphagia and early-onset severe obesity. We aimed to evaluate the effect of setmelanotide on bodyweight in these patients.

METHODS

This multicentre, randomised, 14-week double-blind, placebo-controlled, phase 3 trial followed by a 52-week open-label period, was performed at 12 sites (hospitals, clinics, and universities) in the USA, Canada, the UK, France, and Spain. Patients aged 6 years or older were included if they had a clinical diagnosis of Bardet-Biedl syndrome or Alström syndrome and obesity (defined as BMI >97th percentile for age and sex for those aged 6-15 years and ≥30 kg/m2 for those aged ≥16 years). Patients were randomly assigned (1:1) using a numerical randomisation code to receive up to 3·0 mg of subcutaneous setmelanotide or placebo once per day during the 14-week double-blind period, followed by open-label setmelanotide for 52 weeks. The primary endpoint, measured in the full analysis set, was the proportion of patients aged 12 years or older who reached at least a 10% reduction in bodyweight from baseline after 52 weeks of setmelanotide treatment. This study is registered with ClinicalTrials.gov, NCT03746522.

FINDINGS

Between Dec 10, 2018, and Nov 25, 2019, 38 patients were enrolled and randomly assigned to receive setmelanotide (n=19) or placebo (n=19; 16 with Bardet-Biedl syndrome and three with Alström syndrome in each group). In terms of the primary endpoint, 32·3% (95% CI 16·7 to 51·4; p=0·0006) of patients aged 12 years or older with Bardet-Biedl syndrome reached at least a 10% reduction in bodyweight after 52 weeks of setmelanotide. The most commonly reported treatment-emergent adverse events were skin hyperpigmentation (23 [61%] of 38) and injection site erythema (18 [48%]). Two patients had four serious adverse events (blindness, anaphylactic reaction, and suicidal ideation); none were considered related to setmelanotide treatment.

INTERPRETATION

Setmelanotide resulted in significant bodyweight reductions in patients with Bardet-Biedl syndrome; however, these results were inconclusive in patients with Alström syndrome. These results support the use of setmelanotide and provided the necessary evidence for approval of this drug as the first treatment for obesity in patients with Bardet-Biedl syndrome.

FUNDING

Rhythm Pharmaceuticals.

Sex-split analysis of pathology and motor-behavioral outcomes in a mouse model of CLN8-Batten disease reveals an increased disease burden and trajectory in female Cln8mnd mice

BACKGROUND

CLN8-Batten disease (CLN8 disease) is a rare neurodegenerative disorder characterized phenotypically by progressive deterioration of motor and cognitive abilities, visual symptoms, epileptic seizures, and premature death. Mutations in CLN8 results in characteristic Batten disease symptoms and brain-wide pathology including accumulation of lysosomal storage material, gliosis, and neurodegeneration. Recent investigations of other subforms of Batten disease (CLN1, CLN3, CLN6) have emphasized the influence of biological sex on disease and treatment outcomes; however, little is known about sex differences in the CLN8 subtype. To determine the impact of sex on CLN8 disease burden and progression, we utilized a Cln8^mnd mouse model to measure the impact and progression of histopathological and behavioral outcomes between sexes.

RESULTS

Several notable sex differences were observed in the presentation of brain pathology, including Cln8^mnd female mice consistently presenting with greater GFAP⁺ astrocytosis and CD68⁺ microgliosis in the somatosensory cortex, ventral posteromedial/ventral posterolateral nuclei of the thalamus, striatum, and hippocampus when compared to Cln8^mnd male mice. Furthermore, sex differences in motor-behavioral assessments revealed Cln8^mnd female mice experience poorer motor performance and earlier death than their male counterparts. Cln8^mnd mice treated with an AAV9-mediated gene therapy were also examined to assess sex differences on therapeutics outcomes, which revealed no appreciable differences between the sexes when responding to the therapy.

CONCLUSIONS

Taken together, our results provide further evidence of biologic sex as a modifier of Batten disease progression and outcome, thus warranting consideration when conducting investigations and monitoring therapeutic impact.

Epidemiology, aetiology, interventions and genomics in children with arthrogryposis multiplex congenita: protocol for a multisite registry

INTRODUCTION

Arthrogryposis multiplex congenita (AMC) is an umbrella term including hundreds of conditions with the common clinical manifestation of multiple congenital contractures. AMC affects 1 in 3000 live births and is caused by lack of movement in utero. To understand the long-term needs of individuals diagnosed with a rare condition, it is essential to know the prevalence, aetiology and functional outcomes in a large sample. The development and implementation of a multicentre registry is critical to gather this data. This registry aims to improve health through genetic and outcomes research, and ultimately identify new therapeutic targets and diagnostics for treating children with AMC.

METHODS AND ANALYSIS

Participants for the AMC registry will be recruited from seven orthopaedic hospitals in North America. Enrollment occurs in two phases; Part 1 focuses on epidemiology, aetiology and interventions. For this part, retrospective and cross-sectional data will be collected using a combination of patient-reported outcomes and clinical measures. Part 2 focuses on core subset of the study team, including a geneticist and bioinformatician, identifying causative genes and linking the phenotype to genotype via whole genome sequencing to identify genetic variants and correlating these findings with pedigree, photographs and clinical information. Descriptive analyses on the sample of 400 participants and logistic regression models to evaluate relationships between outcomes will be conducted.

ETHICS AND DISSEMINATION

Ethical approval has been granted from corresponding governing bodies in North America. Dissemination of findings will occur via traditional platforms (conferences, manuscripts) for the scientific community. Other modalities will be employed to ensure that all stakeholders, including youth, families and patient support groups, may be provided with findings derived from the registry. Ensuring the findings are circulated to a maximum amount of interested parties will ensure that the registry can continue to serve as a platform for hypothesis-driven research and further advancement for AMC.

A Versatile and Scalable Platform That Streamlines Data Collection for Patient-Centered Studies: Usability and Feasibility Study

Background

The Food and Drug Administration Center for Biologics Evaluation and Research (CBER) established the Biologics Effectiveness and Safety (BEST) Initiative with several objectives, including the expansion and enhancement of CBER’s access to fit-for-purpose data sources, analytics, tools, and infrastructures to improve the understanding of patient experiences with conditions related to CBER-regulated products. Owing to existing challenges in data collection, especially for rare disease research, CBER recognized the need for a comprehensive platform where study coordinators can engage with study participants and design and deploy studies while patients or caregivers could enroll, consent, and securely participate as well.

Objective

This study aimed to increase awareness and describe the design, development, and novelty of the Survey of Health and Patient Experience (SHAPE) platform, its functionality and application, quality improvement efforts, open-source availability, and plans for enhancement.

Methods

SHAPE is hosted in a Google Cloud environment and comprises 3 parts: the administrator application, participant app, and application programming interface. The administrator can build a study comprising a set of questionnaires and self-report entries through the app. Once the study is deployed, the participant can access the app, consent to the study, and complete its components. To build SHAPE to be scalable and flexible, we leveraged the open-source software development kit, Ionic Framework. This enabled the building and deploying of apps across platforms, including iOS, Android, and progressive web applications, from a single codebase by using standardized web technologies. SHAPE has been integrated with a leading Health Level 7 (HL7®) Fast Healthcare Interoperability Resources (FHIR®) application programming interface platform, 1upHealth, which allows participants to consent to 1-time data pull of their electronic health records. We used an agile-based process that engaged multiple stakeholders in SHAPE’s design and development.

Results

SHAPE allows study coordinators to plan, develop, and deploy questionnaires to obtain important end points directly from patients or caregivers. Electronic health record integration enables access to patient health records, which can validate and enhance the accuracy of data-capture methods. The administrator can then download the study data into HL7® FHIR®–formatted JSON files. In this paper, we illustrate how study coordinators can use SHAPE to design patient-centered studies. We demonstrate its broad applicability through a hypothetical type 1 diabetes cohort study and an ongoing pilot study on metachromatic leukodystrophy to implement best practices for designing a regulatory-grade natural history study for rare diseases.

Conclusions

SHAPE is an intuitive and comprehensive data-collection tool for a variety of clinical studies. Further customization of this versatile and scalable platform allows for multiple use cases. SHAPE can capture patient perspectives and clinical data, thereby providing regulators, clinicians, researchers, and patient advocacy organizations with data to inform drug development and improve patient outcomes.

Rare diseases in healthcare priority setting: should rarity matter?

Rare diseases pose a particular priority setting problem. The UK gives rare diseases special priority in healthcare priority setting. Effectively, the National Health Service is willing to pay much more to gain a quality-adjusted life-year related to a very rare disease than one related to a more common condition. But should rare diseases receive priority in the allocation of scarce healthcare resources? This article develops and evaluates four arguments in favour of such a priority. These pertain to public values, luck egalitarian distributive justice the epistemic difficulties of obtaining knowledge about rare diseases and the incentives created by a higher willingness to pay. The first is at odds with our knowledge regarding popular opinion. The three other arguments may provide a reason to fund rare diseases generously. However, they are either overinclusive because they would also justify funding for many non-rare diseases or underinclusive in the sense of justifying priority for only some rare diseases. The arguments thus fail to provide a justification that tracks rareness as such.

Needs of people with rare diseases that can be supported by electronic resources: a scoping review

OBJECTIVES

Rare diseases are characterised by low incidence, often with little evidence for effective treatments. Isolated patients and specialist centres for rare diseases are increasingly connected, thanks to the internet. This scoping review aimed to identify issues facing people with a rare disease that authors report may be addressed by electronic resources (mobile applications, websites, social media platforms, telehealth and online portals).

DESIGN

Scoping review guided by the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines.

DATA SOURCES

Medline, Embase and PsycInfo were searched, supplemented by hand searches of selected journals, in July 2021.

ELIGIBILITY CRITERIA

Peer-reviewed literature in English was searched using terms for rare disease (incidence <1:2000), electronic modalities (eg, mobile phone) and patient support terms. No date limit was set. Conference abstracts were included.

DATA EXTRACTION AND SYNTHESIS

Data extracted: rare disease/group of diseases, name of the e-resource, need identified in the patient cohort, features of the e-resource, any other findings or observations of interest. From this, a framework was developed synthesising features across diseases and resources.

RESULTS

Seventy-two papers were found (from 383). Fifty-six electronic resources were described in 64 papers, while 12 papers were exploratory studies. Cystic fibrosis (n=28) was the most frequently addressed, followed by haemophilia (n=16).Four domains and 23 subdomains of needs were extracted from the papers. The domains of needs were: support for self-management, access to high-quality information, access to appropriate specialist services, and social support. Subdomains are sometimes related to needs of individual rare diseases (eg, social isolation due to infection risk in people with cystic fibrosis). Fifteen electronic resources were identified that supported parents of children with rare disorders.

CONCLUSIONS

While it can be argued that rare diseases, per se, may be no less distressing or onerous to care for than a high prevalence disease, rare diseases have unique features: the lengthy odyssey to find a diagnosis, then appropriate specialists, the lack of evidence around effective treatments, guidelines or access to knowledgeable general health service providers. Designers of electronic resources are urged to consult key stakeholders to enhance the effectiveness and usability of resources for people with a rare disease.

Systematic Review: Drug Repositioning for Congenital Disorders of Glycosylation (CDG)

Advances in research have boosted therapy development for congenital disorders of glycosylation (CDG), a group of rare genetic disorders affecting protein and lipid glycosylation and glycosylphosphatidylinositol anchor biosynthesis. The (re)use of known drugs for novel medical purposes, known as drug repositioning, is growing for both common and rare disorders. The latest innovation concerns the rational search for repositioned molecules which also benefits from artificial intelligence (AI). Compared to traditional methods, drug repositioning accelerates the overall drug discovery process while saving costs. This is particularly valuable for rare diseases. AI tools have proven their worth in diagnosis, in disease classification and characterization, and ultimately in therapy discovery in rare diseases. The availability of biomarkers and reliable disease models is critical for research and development of new drugs, especially for rare and heterogeneous diseases such as CDG. This work reviews the literature related to repositioned drugs for CDG, discovered by serendipity or through a systemic approach. Recent advances in biomarkers and disease models are also outlined as well as stakeholders' views on AI for therapy discovery in CDG.

Role of HSP70 chaperone in protein aggregate phenomenon of GNE mutant cells: Therapeutic lead for GNE Myopathy

Limited treatment options and research in understanding the pathomechanisms of rare diseases has raised concerns about their therapeutic development. One such poorly understood ultra-rare neuromuscular disorder is GNE Myopathy (GNEM) which is caused due to mutation in key sialic acid biosynthetic enzyme, GNE. Treatment with sialic acid or its derivatives/precursors slows the disease progression, but curative strategies need to be explored further. Pathologically, muscle biopsy samples of GNEM patients reveal rimmed vacuole formation due to aggregation of β-amyloid, Tau, presenilin proteins with unknown mechanism. The present study aims to understand the mechanism of protein aggregate formation in GNE mutant cells to decipher role of chaperones in disease phenotype. The pathologically relevant GNE mutations expressed as recombinant proteins in HEK cells was used as a model system for GNEM to estimate extent of protein aggregation. We identified HSP70, a chaperone, as binding partner of GNE. Downregulation of HSP70 with altered BAG3, JNK, BAX expression levels was observed in GNE mutant cells. The cell apoptosis was observed in GNE mutation specific manner. An activator of HSP70 chaperone, BGP-15, rescued the phenotypic defects due to GNE mutation, thereby, reducing protein aggregation significantly. The results were further validated in rat skeletal muscle cell lines carrying single Gne allele. Our study suggests that HSP70 activators can be a promising therapeutic target in the treatment of ultra-rare GNE Myopathy disease.

An Approach to Solving the Complex Clinicogenomic Data Landscape in Precision Oncology: Learnings From the Design of WAYFIND-R, a Global Precision Oncology Registry

Precision oncology, where patients are given therapies based on their genomic profile and disease trajectory, is rapidly evolving to become a pivotal part of cancer management, supported by regulatory approvals of biomarker-matched targeted therapies and cancer immunotherapies. However, next-generation sequencing (NGS)-based technologies have revealed an increasing number of molecular-based cancer subtypes with rare patient populations, leading to difficulties in executing/recruiting for traditional clinical trials. Therefore, approval of novel therapeutics based on traditional interventional studies may be difficult and time consuming, with delayed access to innovative therapies. Real-world data (RWD) that describe the patient journey in routine clinical practice can help elucidate the clinical utility of NGS-based genomic profiling, multidisciplinary case discussions, and targeted therapies. We describe key learnings from the setup of WAYFIND-R (NCT04529122), a first-of-its-kind global cancer registry collecting RWD from patients with solid tumors who have undergone NGS-based genomic profiling. The meaning of 'generalizability' and 'high quality' for RWD across different geographic areas was revisited, together with patient recruitment processes, and data sharing and privacy. Inspired by these learnings, WAYFIND-R's design will help physicians discuss patient treatment plans with their colleagues, improve understanding of the impact of treatment decisions/cancer care processes on patient outcomes, and provide a platform to support the design and conduct of further clinical/epidemiologic research. WAYFIND-R demonstrates user-friendly, electronic case report forms, standardized collection of molecular tumor board-based decisions, and a dashboard providing investigators with access to local cohort-level data and the ability to interact with colleagues or search the entire registry to find rare populations. Overall, WAYFIND-R will inform on best practice for NGS-based treatment decisions by clinicians, foster global collaborations between cancer centers and enable robust conclusions regarding outcome data to be drawn, improve understanding of disparities in patients' access to advanced diagnostics and therapies, and ultimately drive advances in precision oncology.

In search of effective therapies: the current landscape of phase II trials in patients with advanced soft tissue sarcoma

PURPOSE

Soft tissue sarcomas (STS) are diagnosed in 4-6 cases per 100 000 people a year and are associated with an unfavorable prognosis. Around one-third of patients will develop metastatic disease that requires palliative systemic therapy. Current therapeutic options have limited activity, and new treatments are tested, mainly in phase II trials. There is high variability and no standardization of phase II designs. We aimed to analyze the current landscape of phase II studies in STS and evaluate how its statistical design can affect the results.

METHODS

Full-text phase II studies published in STS patients between 2005 and 2020 were identified and analyzed.

RESULTS

We have identified 102 trials, of which 77.4% were single-arm trials, 16.7% were randomized comparative trials (RCT), and 5.9% were randomized noncomparative trials. Including multiple cohorts, 22 randomized and 128 single-arm cohorts were analyzed. Nearly 80% of trials reported full statistical bases of the design. Over 20 different primary endpoints were used, with PFS as the most common in RCT trials (81.8%) and ORR (36.7%) and 3-months progression-free survival (PFS) rate (21.9%) in single-arm trials. Overall, 27.3% of RCT and 37.5% of single-arm trials were positive. Among single-arm trials, studies using 3- or 6-month rates were more often positive than those based on ORR.

CONCLUSIONS

There is high heterogeneity in sarcoma trial designs, mainly in primary-endpoint and hypotheses used for size calculation. There is an unmet need for standardization that will incorporate factors associated with the rarity of the disease, outcomes detected in previous trials and real-life studies, and specific characteristics of new therapeutic agents.

A Community-Led Approach as a Guide to Overcome Challenges for Therapy Research in Congenital Disorders of Glycosylation

Congenital Disorders of Glycosylation (CDG) are a large family of rare genetic diseases for which effective therapies are almost nonexistent. To better understand the reasons behind this, to analyze ongoing therapy research and development (R&D) for CDG, and to provide future guidance, a community-led mixed methods approach was organized during the 4th World Conference on CDG for Families and Professionals. In the quantitative phase, electronic surveys pointed to the prioritization of six therapeutic R&D tools, namely biobanks, registries, biomarkers, disease models, natural history studies, and clinical trials. Subsequently, in the qualitative phase, the challenges and solutions associated with these research tools were explored through community-driven think tanks. The multiple challenges and solutions identified administrative/regulatory, communication, financial, technical, and biological issues, which are directly related to three fundamental aspects of therapy R&D, namely data, sample, and patient management. An interdependence was traced between the prioritized tools, with diagnosis and therapies acting as bidirectional triggers that fuel these interrelationships. In conclusion, this study’s pioneering and adaptable community-led methodology identified several CDG therapy R&D gaps, many common to other rare diseases, without easy solutions. However, the strong proactive attitude towards research, based on inclusive and international partnerships and involving all members of the CDG community, sets the direction for better future therapy R&D.

Recent Advances in Mitochondrial Diseases: from Molecular Insights to Therapeutic Perspectives

Mitochondria are double-membraned cytoplasmic organelles that are responsible for the production of energy in eukaryotic cells. The process is completed through oxidative phosphorylation (OXPHOS) by the respiratory chain (RC) in mitochondria. Thousands of mitochondria may be present in each cell, depending on the function of that cell. Primary mitochondria disorder (PMD) is a clinically heterogeneous disease associated with germline mutations in mitochondrial DNA (mtDNA) and/or nuclear DNA (nDNA) genes, and impairs mitochondrial structure and function. Mitochondrial dysfunction can be detected in early childhood and may be severe, progressive and often multi-systemic, involving a wide range of organs. Understanding epigenetic factors and pathways mutations can help pave the way for developing an effective cure. However, the lack of information about the disease (including age of onset, symptoms, clinical phenotype, morbidity and mortality), the limits of current preclinical models and the wide range of phenotypic presentations hamper the development of effective medicines. Although new therapeutic approaches have been introduced with encouraging preclinical and clinical outcomes, there is no definitive cure for PMD. This review highlights recent advances, particularly in children, in terms of etiology, pathophysiology, clinical diagnosis, molecular pathways and epigenetic alterations. Current therapeutic approaches, future advances and proposed new therapeutic plans will also be discussed.