Experimental Neurotherapeutics: Surfing the Tidal Wave of New Opportunities.

The subspecialty of experimental neurotherapeutics trains neurologists in discovering and developing new treatments for neurologic diseases. Based on development of exciting new treatments for genetic and inflammatory diseases, we predict that there will be many other breakthroughs. The job market has expanded rapidly in academia, the pharmaceutical industry, government, and not-for-profit sectors; many new opportunities can be anticipated. The burgeoning opportunities in the field mandate that training address the challenges of overcoming obstacles in therapeutic discovery, implementation science, and development of affordable and equitably available treatments. ANN NEUROL 2023;93:427-430.

Biodistribution of onasemnogene abeparvovec DNA, mRNA and SMN protein in human tissue.

Spinal muscular atrophy type 1 (SMA1) is a debilitating neurodegenerative disease resulting from survival motor neuron 1 gene (SMN1) deletion/mutation. Onasemnogene abeparvovec (formerly AVXS-101) is a gene therapy that restores SMN production via one-time systemic administration. The present study demonstrates widespread biodistribution of vector genomes and transgenes throughout the central nervous system (CNS) and peripheral organs, after intravenous administration of an AAV9-mediated gene therapy. Two symptomatic infants with SMA1 enrolled in phase III studies received onasemnogene abeparvovec. Both patients died of respiratory complications unrelated to onasemnogene abeparvovec. One patient had improved motor function and the other died shortly after administration before appreciable clinical benefit could be observed. In both patients, onasemnogene abeparvovec DNA and messenger RNA distribution were widespread among peripheral organs and in the CNS. The greatest concentration of vector genomes was detected in the liver, with an increase over that detected in CNS tissues of 300-1,000-fold. SMN protein, which was low in an untreated SMA1 control, was clearly detectable in motor neurons, brain, skeletal muscle and multiple peripheral organs in treated patients. These data support the fact that onasemnogene abeparvovec has effective distribution, transduction and expression throughout the CNS after intravenous administration and restores SMN expression in humans.

Clinical Design and Analysis Strategies for the Development of Gene Therapies: Considerations for Quantitative Drug Development in the Age of Genetic Medicine.

Cell and gene therapies have shown enormous promise across a range of diseases in recent years. Numerous adoptive cell therapy modalities as well as systemic and direct-to-target tissue gene transfer administrations are currently in clinical development. The clinical trial design, development, reporting, and analysis of novel cell and gene therapies can differ significantly from established practices for small molecule drugs and biologics. Here, we discuss important quantitative considerations and key competencies for drug developers in preclinical requirements, trial design, and lifecycle planning for gene therapies. We argue that the unique development path of gene therapies requires practicing quantitative drug developers-statisticians, pharmacometricians, pharmacokineticists, epidemiologists, and medical and translational science leads-to exercise active collaboration and cross-functional learning across development stages.

Hepatotoxicity following administration of onasemnogene abeparvovec (AVXS-101) for the treatment of spinal muscular atrophy.

BACKGROUND & AIMS: Spinal muscular atrophy (SMA) is an autosomal recessive, childhood-onset motor neuron disease. Onasemnogene abeparvovec (OA) is a gene therapy designed to address SMA's root cause. In pivotal mouse toxicology studies, the liver was identified as a major site of OA toxicity. Clinical data reflect elevations in serum aminotransferase concentrations, with some reports of serious acute liver injury. Prophylactic prednisolone mitigates these effects. Herein, we aim to provide pragmatic, supportive guidance for identification, management, and risk mitigation of potential drug-induced liver injury. METHODS: Data from 325 patients with SMA who had received OA through 31 December 2019, in 5 clinical trials, a managed access program (MAP), and a long-term registry (RESTORE), and through commercial use, were analyzed. Liver-related adverse events, laboratory data, concomitant medications, and prednisolone use were analyzed. RESULTS: Based on adverse events and laboratory data, 90 of 100 patients had elevated liver function test results (alanine aminotransferase, and/or aspartate aminotransferase, and/or bilirubin concentrations). Of these, liver-associated adverse events were reported for 34 of 100 (34%) and 10 of 43 (23%) patients in clinical trials and MAP/RESTORE, respectively. Two patients in MAP had serious acute liver injury, which resolved completely. While all events in the overall population resolved, prednisolone treatment duration varied (range: 33-229 days), with a majority receiving prednisolone for 60-120 days. More than 60% had elevations in either alanine aminotransferase, aspartate aminotransferase, or bilirubin concentrations prior to dosing. Greater than 40% received potentially hepatotoxic concomitant medications. CONCLUSIONS: Hepatotoxicity is a known risk associated with OA use. Practitioners should identify contributing factors and mitigate risk through appropriate monitoring and intervention. LAY SUMMARY: Onasemnogene abeparvovec is a type of medicine called a "gene therapy," which is used to treat babies and young children who have a rare, serious inherited condition called "spinal muscular atrophy" (SMA). It works by supplying a fully functioning copy of the survival motor neuron or SMN gene, which then helps the body produce enough SMN protein. However, it can cause an immune response that could lead to an increase in enzymes produced by the liver. This article provides information about the liver injury and how to prevent and recognize if it happens, so that it may be treated properly.

Model consent clauses for rare disease research.

BACKGROUND: Rare Disease research has seen tremendous advancements over the last decades, with the development of new technologies, various global collaborative efforts and improved data sharing. To maximize the impact of and to further build on these developments, there is a need for model consent clauses for rare diseases research, in order to improve data interoperability, to meet the informational needs of participants, and to ensure proper ethical and legal use of data sources and participants' overall protection. METHODS: A global Task Force was set up to develop model consent clauses specific to rare diseases research, that are comprehensive, harmonized, readily accessible, and internationally applicable, facilitating the recruitment and consent of rare disease research participants around the world. Existing consent forms and notices of consent were analyzed and classified under different consent themes, which were used as background to develop the model consent clauses. RESULTS: The IRDiRC-GA4GH MCC Task Force met in September 2018, to discuss and design model consent clauses. Based on analyzed consent forms, they listed generic core elements and designed the following rare disease research specific core elements; Rare Disease Research Introductory Clause, Familial Participation, Audio/Visual Imaging, Collecting, storing, sharing of rare disease data, Recontact for matching, Data Linkage, Return of Results to Family Members, Incapacity/Death, and Benefits. CONCLUSION: The model consent clauses presented in this article have been drafted to highlight consent elements that bear in mind the trends in rare disease research, while providing a tool to help foster harmonization and collaborative efforts.

Privacy-Preserving Linkage of Genomic and Clinical Data Sets.

The capacity to link records associated with the same individual across data sets is a key challenge for data-driven research. The challenge is exacerbated by the potential inclusion of both genomic and clinical data in data sets that may span multiple legal jurisdictions, and by the need to enable re-identification in limited circumstances. Privacy-Preserving Record Linkage (PPRL) methods address these challenges. In 2016, the Interdisciplinary Committee of the International Rare Diseases Research Consortium (IRDiRC) launched a task team to explore approaches to PPRL. The task team is a collaboration with the Global Alliance for Genomics and Health (GA4GH) Regulatory and Ethics and Data Security Work Streams, and aims to prepare policy and technology standards to enable highly reliable linking of records associated with the same individual without disclosing their identity except under conditions in which the use of the data has led to information of importance to the individual's safety or health, and applicable law allows or requires the return of results. The PPRL Task Force has examined the ethico-legal requirements, constraints, and implications of PPRL, and has applied this knowledge to the exploration of technology methods and approaches to PPRL. This paper reports and justifies the findings and recommendations thus far.

From scientific discovery to treatments for rare diseases - the view from the National Center for Advancing Translational Sciences - Office of Rare Diseases Research.

We now live in a time of unprecedented opportunities to turn scientific discoveries into better treatments for the estimated 30 million people in the US living with rare diseases. Despite these scientific advances, more than 90% of rare diseases still lack an effective treatment. New data and genetics technologies have resulted in the first transformational new treatments for a handful of rare diseases. This challenges us as a society to accelerate progress so that no disease and no patient is, ultimately, left behind in getting access to safe and effective therapeutics. This article reviews initiatives of the National Center for Advancing Translational Sciences (NCATS) Office of Rare Diseases Research (ORDR) that are aimed at catalyzing rare diseases research. These initiatives fall into two groups: Promoting information sharing; and building multi-disciplinary multi-stakeholder collaborations. Among ORDR's information sharing initiatives are GARD (The Genetics and Rare Diseases Information Center), RaDaR (The Rare Diseases Registries Program) and the NCATS Toolkit for Patient-Focused Therapy Development (Toolkit). Among the collaboration initiatives are the RDCRN (Rare Diseases Clinical Research Network), and the NCATS ORDR support for conferences and workshops. Despite the success of these programs, there remains substantial work to be done to build enhanced collaborations, clinical harmonization and interoperability, and stakeholder engagement so that the recent scientific advances can benefit all patients on the long list of rare diseases waiting for help.

Facilitating Clinical Studies in Rare Diseases.

In recent years, there have been many scientific advances and new collaborations for rare diseases research and, ultimately, the health of patients living with rare diseases. However, for too many rare diseases, there still is no effective treatment, and our understanding of the incidence, prevalence, and underlying etiology is incomplete. To facilitate the studies needed to answer the many open questions there is a great need for the active involvement of all stakeholders, most importantly of patient groups. Also, the creation of streamlined infrastructure for performing multi-site clinical studies is critical, as is the engagement of multi-disciplinary teams with shared focus on a group of diseases. Another essential component of such efforts is to collect standardized data so that downstream meta-analyses and data sharing can be facilitated. To ensure high-quality protocols and datasets, a central data management and coordinating center is important. Since there are more than 6000 rare diseases, instead of focusing on single rare disease, it is more impactful to create platforms and methods that can support a group of rare diseases.

Improved Diagnosis and Care for Rare Diseases through Implementation of Precision Public Health Framework.

Public health relies on technologies to produce and analyse data, as well as effectively develop and implement policies and practices. An example is the public health practice of epidemiology, which relies on computational technology to monitor the health status of populations, identify disadvantaged or at risk population groups and thereby inform health policy and priority setting. Critical to achieving health improvements for the underserved population of people living with rare diseases is early diagnosis and best care. In the rare diseases field, the vast majority of diseases are caused by destructive but previously difficult to identify protein-coding gene mutations. The reduction in cost of genetic testing and advances in the clinical use of genome sequencing, data science and imaging are converging to provide more precise understandings of the 'person-time-place' triad. That is: who is affected (people); when the disease is occurring (time); and where the disease is occurring (place). Consequently we are witnessing a paradigm shift in public health policy and practice towards 'precision public health'.Patient and stakeholder engagement has informed the need for a national public health policy framework for rare diseases. The engagement approach in different countries has produced highly comparable outcomes and objectives. Knowledge and experience sharing across the international rare diseases networks and partnerships has informed the development of the Western Australian Rare Diseases Strategic Framework 2015-2018 (RD Framework) and Australian government health briefings on the need for a National plan.The RD Framework is guiding the translation of genomic and other technologies into the Western Australian health system, leading to greater precision in diagnostic pathways and care, and is an example of how a precision public health framework can improve health outcomes for the rare diseases population.Five vignettes are used to illustrate how policy decisions provide the scaffolding for translation of new genomics knowledge, and catalyze transformative change in delivery of clinical services. The vignettes presented here are from an Australian perspective and are not intended to be comprehensive, but rather to provide insights into how a new and emerging 'precision public health' paradigm can improve the experiences of patients living with rare diseases, their caregivers and families.The conclusion is that genomic public health is informed by the individual and family needs, and the population health imperatives of an early and accurate diagnosis; which is the portal to best practice care. Knowledge sharing is critical for public health policy development and improving the lives of people living with rare diseases.

The International Rare Diseases Research Consortium: Policies and Guidelines to maximize impact.

The International Rare Diseases Research Consortium (IRDiRC) has agreed on IRDiRC Policies and Guidelines, following extensive deliberations and discussions in 2012 and 2013, as a first step towards improving coordination of research efforts worldwide. The 25 funding members and 3 patient umbrella organizations (as of early 2013) of IRDiRC, a consortium of research funders that focuses on improving diagnosis and therapy for rare disease patients, agreed in Dublin, Ireland in April 2013 on the Policies and Guidelines that emphasize collaboration in rare disease research, the involvement of patients and their representatives in all relevant aspects of research, as well as the sharing of data and resources. The Policies and Guidelines provide guidance on ontologies, diagnostics, biomarkers, patient registries, biobanks, natural history, therapeutics, models, publication, intellectual property, and communication. Most IRDiRC members-currently nearly 50 strong-have since incorporated its policies in their funding calls and some have chosen to exceed the requirements laid out, for instance in relation to data sharing. The IRDiRC Policies and Guidelines are the first, detailed agreement of major public and private funding organizations worldwide to govern rare disease research, and may serve as a template for other areas of international research collaboration. While it is too early to assess their full impact on research productivity and patient benefit, the IRDiRC Policies and Guidelines have already contributed significantly to improving transparency and collaboration in rare disease research.

Treatment Advances in Spinal Muscular Atrophy.

PURPOSE OF REVIEW: Spinal muscular atrophy (SMA) is a genetic disorder of motor neurons in the anterior horns of the spinal cord and brainstem that results in muscle atrophy and weakness. SMA is an autosomal recessive disease linked to deletions of the SMN1 gene on chromosome 5q. Humans have a duplicate gene (SMN2) whose product can mitigate disease severity, leading to the variability in severity and age of onset of disease, and is therefore a target for drug development. RECENT FINDINGS: Advances in preclinical and clinical trials have paved the way for novel therapeutic options for SMA patients, including many currently in clinical trials. In 2016, the first treatment for SMA has been approved in the USA, an antisense oligonucleotide that increases full-length protein product derived from SMN2. The approval of a first treatment for SMA and the rapid advances in clinical trials provide the prospect for multiple approaches to disease modification. There are several other promising therapeutics in different stages of development, based on approaches such as neuroprotection, or gene therapy.

International Cooperation to Enable the Diagnosis of All Rare Genetic Diseases.

Provision of a molecularly confirmed diagnosis in a timely manner for children and adults with rare genetic diseases shortens their "diagnostic odyssey," improves disease management, and fosters genetic counseling with respect to recurrence risks while assuring reproductive choices. In a general clinical genetics setting, the current diagnostic rate is approximately 50%, but for those who do not receive a molecular diagnosis after the initial genetics evaluation, that rate is much lower. Diagnostic success for these more challenging affected individuals depends to a large extent on progress in the discovery of genes associated with, and mechanisms underlying, rare diseases. Thus, continued research is required for moving toward a more complete catalog of disease-related genes and variants. The International Rare Diseases Research Consortium (IRDiRC) was established in 2011 to bring together researchers and organizations invested in rare disease research to develop a means of achieving molecular diagnosis for all rare diseases. Here, we review the current and future bottlenecks to gene discovery and suggest strategies for enabling progress in this regard. Each successful discovery will define potential diagnostic, preventive, and therapeutic opportunities for the corresponding rare disease, enabling precision medicine for this patient population.

'IRDiRC Recognized Resources': a new mechanism to support scientists to conduct efficient, high-quality research for rare diseases.

The International Rare Diseases Research Consortium (IRDiRC) has created a quality label, 'IRDiRC Recognized Resources', formerly known as 'IRDiRC Recommended'. It is a peer-reviewed quality indicator process established based on the IRDiRC Policies and Guidelines to designate resources (ie, standards, guidelines, tools, and platforms) designed to accelerate the pace of discoveries and translation into clinical applications for the rare disease (RD) research community. In its first year of implementation, 13 resources successfully applied for this designation, each focused on key areas essential to IRDiRC objectives and to the field of RD research more broadly. These included data sharing for discovery, knowledge organisation and ontologies, networking patient registries, and therapeutic development. 'IRDiRC Recognized Resources' is a mechanism aimed to provide community-approved contributions to RD research higher visibility, and encourage researchers to adopt recognised standards, guidelines, tools, and platforms that facilitate research advances guided by the principles of interoperability and sharing.

Patterns of disease progression in type 2 and 3 SMA: Implications for clinical trials.

The aim of the study was to establish 12-month changes in the Hammersmith Functional motor scale in a large cohort of SMA patients, to identify patterns of disease progression and the effect of different variables. 268 patients were included in this multicentric study. Their age ranged between 2.5 and 55.5 years at baseline, 68 were ambulant and 200 non-ambulant. The baseline scores ranged between 0 and 66 (mean 23.91, SD 20.09). The 12-month change was between -14 and +9 (mean -0.56, SD 2.72). Of the 268 patients, 206 (76.86%) had changes between -2 and +2 points. Ambulant and non-ambulant subjects had a different relationship between baseline values and age (p for age X ambulation interaction = 0.007). There was no association with age in ambulant subjects, while there was a significant heterogeneity at different age for non-ambulant patients (p < 0.001). The 12-month change (adjusted for baseline) was not associated with age in ambulant patients (p = 0.34), but it was significantly different among various age groups in non-ambulant patients. Our results suggest that there are different profiles of progression in ambulant and non-ambulant patients, and that age may play an important role in the progression of non-ambulant patients.

Old measures and new scores in spinal muscular atrophy patients.

INTRODUCTION: A recent Rasch analysis performed on the Hammersmith Functional Motor Scale-Expanded (HFMSE) in patients with spinal muscular atrophy (SMA) identified issues impacting scale validity, redundant items, and disordered thresholds on some items. METHODS: We modified the HMFSE scoring based on the Rasch analysis and on expert consensus to establish whether the traditional scoring overestimated the number of patients with changes within 2 points from baseline. Data were collected retrospectively from multicenter data sets in 255 type 2 and 3 SMA patients. RESULTS: The mean 12-month changes using the new and the traditional scoring system did not differ significantly (P > 0.05). The numbers of patients who improved or decreased by >2 points were also similar. CONCLUSIONS: The presence of outliers using the traditional scoring system was not due to overestimation of changes in activities that were tested bilaterally or to discrepancies in the scoring hierarchy of individual items.