Gene therapy as a potential therapeutic option for Duchenne muscular dystrophy: A qualitative preference study of patients and parents

Genetic Interventions for Spinocerebellar Ataxia and Huntington's Disease: A Qualitative Study of the Patient Perspective

Background

For various genetic disorders characterized by expanded cytosine-adenine-guanine (CAG) repeats, such as spinocerebellar ataxia (SCA) subtypes and Huntington's disease (HD), genetic interventions are currently being tested in different clinical trial phases. The patient's perspective on such interventions should be included in the further development and implementation of these new treatments.

Objective

To obtain insight into the thoughts and perspectives of individuals with SCA and HD on genetic interventions.

Methods

In this qualitative study, participants were interviewed using semi-structured interview techniques. Topics discussed were possible risks and benefits, and logistic factors such as timing, location and expertise. Data were analyzed using a generic thematic analysis. Responses were coded into superordinate themes.

Results

Ten participants (five with SCA and five with HD) were interviewed. In general, participants seemed to be willing to undergo genetic interventions. Important motives were the lack of alternative disease-modifying treatment options, the hope for slowing down disease progression, and preservation of current quality of life. Before undergoing genetic interventions, participants wished to be further informed. Logistic factors such as mode and frequency of administration, expertise of the healthcare provider, and timing of treatment are of influence in the decision-making process.

Conclusions

This study identified assumptions, motives, and topics that require further attention before these new therapies, if proven effective, can be implemented in clinical practice. The results may help in the design of care pathways for genetic interventions for these and other rare genetic movement disorders.

Comparing Preferences for Disease Profiles: A Discrete Choice Experiment from a US Societal Perspective

OBJECTIVES

There is increasing interest in expanding the elements of value to be considered when making health policy decisions. To help inform value frameworks, this study quantified preferences for disease attributes in a general public sample and examined which combination of attributes (disease profiles) are considered most important for research and treatment.

METHODS

A discrete choice experiment (DCE) was conducted in a US general population sample, recruited through online consumer panels. Respondents were asked to select one of a set of health conditions they believed to be most important, characterized by attributes defined by a previous qualitative study: onset age; cause of disease; life expectancy; caregiver requirement; symptom burden (characterized by the Health Utilities Index with varying levels of ambulation independence, dexterity limitations, and degree of pain and discomfort); and disease prevalence. A fractional factorial DCE design was implemented using R, and 60 choice sets were generated (separated into blocks of 10 per participant). Data were analyzed using a mixed-logit regression model, and results used to assess the likelihood of preferring disease profiles. Based on individual attribute preferences, overall preferences for disease profiles, including a profile aligned with Duchenne muscular dystrophy (DMD), were compared.

RESULTS

Fifty-two percent of respondents (n = 537) were female, and 70.6% were aged 18-54 years. Attributes considered most important were those related to life expectancy (odds ratio [OR], 95% confidence interval [CI] 1.88 [1.56-2.27] for a 50% reduction in remaining life expectancy vs no impact), and symptom burden (OR [95% CI] 1.84 [1.47-2.31] for severe vs mild burden). Greater importance was also found for pediatric onset, caregiver requirement, and diseases affecting more people. As an example of disease profile preferences, a DMD-like pediatric inherited disease with 50% reduction in life expectancy, extensive caregiver requirement, severe symptom burden, and 1:5000 prevalence had 2.37-fold higher odds of being selected as important versus an equivalent disease with adult onset and no life expectancy reduction.

CONCLUSIONS

Of disease attributes included in this DCE, respondents valued higher prevalence of disease, life expectancy and symptom burden as most important for prioritizing research and treatment. Based on expressed attribute preferences, a case study of an inherited pediatric disease involving substantial reductions to length and quality of life and requiring caregiver support has relatively high odds of being identified as important compared to diseases reflecting differing attribute profiles. These findings can help inform expansions of value frameworks by identifying important attributes from the societal perspective.

Perspectives of the Friedreich ataxia community on gene therapy clinical trials

Gene therapy is a potential treatment for Friedreich ataxia, with multiple programs on the horizon. The purpose of this study was to collect opinions about gene therapy from individuals 14 years or older with Friedreich ataxia or parents/caregivers of Friedreich ataxia patients who were diagnosed as children 17 or younger. Participants were asked to complete a survey after reading brief educational materials regarding gene therapy. Most of the patients captured in this survey have an early-onset (classical) presentation of the disease. Participants expressed urgency in participating in gene therapy clinical trials despite the associated risks. About half of the respondents believed that gene therapy would cease progression or minimize symptoms, whereas nearly one-fourth expected to be cured. The survey also revealed how participants perceive their symptom burden, because a substantial majority reported that balance/walking issues most interfere with their quality of life and would be the symptom they would prioritize treating. Although not statistically significant, more caregivers prioritized treating cardiomyopathy than patients. This study provides valuable information on priorities, beliefs, and expectations regarding gene therapy and serves to guide future gene therapy opinion studies and gene therapy trial design.

Draft Guidance for Industry Duchenne Muscular Dystrophy, Becker Muscular Dystrophy, and Related Dystrophinopathies - Developing Potential Treatments for the Entire Spectrum of Disease

Background

Duchenne muscular dystrophy (DMD) and related dystrophinopathies are neuromuscular conditions with great unmet medical needs that require the development of effective medical treatments.

Objective

To aid sponsors in clinical development of drugs and therapeutic biological products for treating DMD across the disease spectrum by integrating advancements, patient registries, natural history studies, and more into a comprehensive guidance.

Methods

This guidance emerged from collaboration between the FDA, the Duchenne community, and industry stakeholders. It entailed a structured approach, involving multiple committees and boards. From its inception in 2014, the guidance underwent revisions incorporating insights from gene therapy studies, cardiac function research, and innovative clinical trial designs.

Results

The guidance provides a deeper understanding of DMD and its variants, focusing on patient engagement, diagnostic criteria, natural history, biomarkers, and clinical trials. It underscores patient-focused drug development, the significance of dystrophin as a biomarker, and the pivotal role of magnetic resonance imaging in assessing disease progression. Additionally, the guidance addresses cardiomyopathy's prominence in DMD and the burgeoning field of gene therapy.

Conclusions

The updated guidance offers a comprehensive understanding of DMD, emphasizing patient-centric approaches, innovative trial designs, and the importance of biomarkers. The focus on cardiomyopathy and gene therapy signifies the evolving realm of DMD research. It acts as a crucial roadmap for sponsors, potentially leading to improved treatments for DMD.

Eliciting Exploratory Patient Preference Data: A Case Study in a Rare Disease

INTRODUCTION

Qualitative and quantitative methods provide different and complementary insights into patients' preferences for treatment.

OBJECTIVE

The aim of this study was to use a novel, mixed-methods approach employing qualitative and quantitative approaches to generate preliminary insights into patient preferences for the treatment of a rare disease-generalized myasthenia gravis (gMG).

METHODS

We conducted a mixed-methods study to collect exploratory qualitative and quantitative patient preference information and generate informative results within a condensed timeline (about 4 months). Recruitment was facilitated by an international health research firm. Study participants first reviewed a brief document describing six treatment attributes (to facilitate more efficient review of the material during the focus groups) and were then provided a link to complete an online quantitative survey with a single risk threshold task. They then participated in online focus groups, during which they discussed qualitative questions about their experience with gMG treatment and completed up to three quantitative threshold tasks, the first of which repeated the threshold task from the online survey.

RESULTS

The study elicited both quantitative data on 18 participants' risk tolerance and qualitative data on their treatment experience, additional treatment attributes of importance, the reasoning behind their preferences, and the trade-offs they were willing to make. Most participants (n = 15) chose the same hypothetical treatment in the first threshold task in the online survey and the focus groups. Focus group discussions provided insights into participants' choices in the threshold tasks, confirmed that all the attributes were relevant, and helped clarify what was important about the attributes.

CONCLUSIONS

Patient preference information can be collected using a variety of approaches, both qualitative and quantitative, tailored to fit the research needs of a study. The novel mixed-methods approach employed in this study efficiently captured patient preference data that were informative for exploratory research, internal decision making, and future research.

A qualitative study to understand the Duchenne muscular dystrophy experience from the parent/patient perspective

BACKGROUND

Duchenne muscular dystrophy (DMD) is a rare, severe, fatal neuromuscular disease characterized by progressive atrophy and muscle weakness, resulting in loss of ambulation, decreased upper body function, and impaired cardiorespiratory function. This study aimed to generate qualitative evidence to describe the primary symptoms and impacts of DMD in ambulatory and non-ambulatory patients as reported by patient/caregiver dyads. Information was also gathered on expectations for future DMD treatments.

METHODS

Forty-six dyads (caregiver and patients with DMD aged 4 to 22 years) participated in 60-min semi-structured video interviews. Interview transcripts were analyzed using thematic analysis. Differences in experiences with DMD by ambulation status were examined.

RESULTS

Mean ages of ambulatory (n = 28) and non-ambulatory participants (n = 18) were 8.7 and 11.3 years, respectively, with an average age of diagnosis of 3.7 years (SD = 2.3). The primary symptoms reported by both groups were lack of strength (ambulatory: n = 28, 100.0%; non-ambulatory: n = 17, 94.4%) and fatigue (ambulatory: n = 24, 85.7%; non-ambulatory: n = 14, 77.8%). Physical function was the domain that was most impacted by DMD, with participants describing progressive decline of physical function due to loss of physical strength as the primary defining feature of the disease across all stages of ambulatory ability. For those who maintained ambulatory ability at the time of the interview, physical function impacts described impaired mobility (e.g., climbing stairs: n = 16, 57.1%; running: n = 13, 46.4%), impaired upper body function, in particular fine motor skills like holding a pen/pencil or buttoning clothes (n = 17, 60.7%), problem with transfers (e.g., getting off the floor: n = 10, 35.7%), and activities of daily living (ADLs; n = 15, 53.6%). For non-ambulatory participants, the functional impacts most frequently described were problems with transfers (e.g., getting in/out of bed: n = 13, 72.2%; getting in/out of chair or position in bed: both n = 10, 55.6%), impaired upper body function (reaching: n = 14, 77.8%), and ADLs (n = 15, 83.3%). Meaningful treatment goals differed by ambulatory status; for ambulatory participants, goals included maintaining current functioning (n = 20, 71.4%), improving muscle strength (n = 7, 25.9%), and reducing fatigue (n = 6, 22.2%). For non-ambulatory participants, these included increased upper body strength (n = 8, 42.1%) and greater independence in ADLs (n = 6, 31.6%). A preliminary conceptual model was developed to illustrate the primary symptoms and physical function impacts of DMD and capture their relationship to disease progression.

CONCLUSION

This study contributes to the limited qualitative literature by characterizing impacts of physical limitations and symptoms of DMD on disease progression and thus providing insights into the lived experience with DMD. Differences in treatment goals were also identified based on ambulatory status. Taken together, these findings can help inform patient-centered measurement strategies for evaluating outcomes in DMD clinical research.

The Lived Experience of Pediatric Gene Therapy: A Scoping Review

Little is known about patients' and families' lived experiences of participating in pediatric gene therapy (GT) clinical trials. Currently, pediatric GT research targets a broad range of indications--including rare and ultra-rare diseases--which vary in severity and in the availability of alternative therapies. Pediatric GT differs meaningfully from adult GT because the decision to participate involves a dyad of both the child and parent or caregiver/s. It is critical to understand patients' and caregivers' perceptions and experiences of social, emotional, physical, and logistical burdens or benefits of participating in such trials, and how they weigh and prioritize these factors when deciding whether to participate. We conducted a scoping review of the current literature in this subject area with objectives to (1) provide an overview of existing literature, (2) identify gaps and areas for further research, and (3) better understand the lived impact of pediatric GT research on patients and their parents/caregivers. Four themes emerged, including (1) weighing risks and benefits (2) timing of GT trial participation, (3) value of clear communication, and (4) potential impact on quality of life. Notably, our sample surfaced articles about how patients/parents/caregivers were thinking about GT-their understanding of its safety, efficacy, and risks-rather than accounts of their experiences, which was our initial intention. Nevertheless, our findings offer useful insights to improve the informed consent process and promote a more patient- and family-centered approach. Moreover, our findings can contribute to patient advocacy organizations' efforts to develop educational materials tailored to patients' and families' expressed informational needs and perspectives, and can inform more patient- and family-centered policies from GT clinical trial sponsors.

How Great a Risk Do You Take? A Qualitative Study Exploring Attitudes of Individuals with Friedreich Ataxia Toward Gene Therapy

Scientists and pharmaceutical companies are working toward delivering gene therapy (GT) for Friedreich ataxia (FRDA). Understanding the views of people with lived experience of FRDA and their parents toward GT is essential to inform trial design and identify potential barriers to participation in clinical trials. The goals of this study were to identify the attitudes toward GT held by individuals with FRDA and parents of individuals with FRDA, and to explore how these may impact future trials for this condition. Audiorecorded, semistructured, qualitative interviews with 19 Australians explored experiences of FRDA, knowledge about clinical trials, views on GT, including risks and benefits, and potential barriers to participation in trials. Participants included thirteen individuals living with FRDA aged between 15-43 years, and six parents of children with FRDA aged 4-12 years of age. Thematic analysis of the interviews identified six main themes. Findings from this study indicate there is strong desire for information regarding GT in FRDA, however the current level of uncertainty around GT makes decision making challenging. The desire to maintain functional status and avoid additional risk of deterioration from an investigational treatment was apparent. Importantly, neurological targets were identified as preferred for GT trials. Further research is required to identify if attitudes and perceptions differ according to geographical location and disease stage.

Public Attitudes About the Use of Gene Therapy in Mainland China

Importance

In addition to technical barriers, public attitudes about the use of gene therapy have an important association with the clinical implementation of gene therapy.

Objective

To investigate the factors associated with public acceptance of gene therapy among individuals in China.

Design, Setting, and Participants

This cross-sectional study used data from a survey conducted among 21 880 individuals in mainland China from June 20 to August 31, 2022.

Main Outcomes and Measures

Stepwise linear regression was used to analyze factors associated with public acceptance of gene therapy in 5 key areas: basic personal information (gender, region, age, and educational level), family situation (marital status, children, and cousins), economic status (assets, debts, and insurance coverage), health knowledge (health literacy score and media use), and physical health status (chronic illness, cancer, European Quality of Life 5-Dimension 5-Level version [EQ-5D-5L] score, and Brief Illness Perception Questionnaire [BIPQ] score). Acceptance scores were calculated based on a visual analog scale (range, 0-100, with higher scores indicating higher acceptance of gene therapy). Further subgroup analysis was carried out in different age subgroups and populations with or without chronic diseases.

Results

A total of 21 880 participants (mean [SD] age, 39.4 [18.9] years; 10 947 female participants [50.0%]; 10 933 male participants [50.0%]) were analyzed in this study. The mean (SD) acceptance score of gene therapy in the survey was 60.56 (27.60). Compared with people aged 60 years or older, those aged 12 to 18 years had higher acceptance of gene therapy (β = 1.48 [95% CI, 0.09-2.88]), while groups aged 19 to 30 years (β = -3.43 [95% CI, -4.80 to -2.07]), 31 to 44 years (β = -1.44 [95% CI, -2.76 to -0.12]), and 45 to 59 years (β = -2.05 [95% CI, -3.27 to -0.83]) had lower acceptance. Compared with people living in Eastern China, those in Central China had lower acceptance of gene therapy (β = -1.58 [95% CI, -2.54 to -0.62]), while those in Western China had higher acceptance (β = 0.92 [95% CI, 0.09-1.76]). Higher educational level (undergraduate or above vs junior high or below) was associated with higher acceptance of gene therapy (β = 1.56 [95% CI, 0.49-2.63]). Number of properties owned was also associated with higher acceptance of gene therapy (2 vs 0: β = 2.38 [95% CI, 1.04-3.72]; ≥3 vs 0: β = 4.66 [95% CI, 2.92-6.39]). Diagnosis of chronic disease was associated with lower acceptance of gene therapy (β = -17.86 [95% CI, -20.49 to -15.24]), while diagnosis of cancer was associated with higher acceptance (β = 6.99 [95% CI, 1.84-12.14]). Higher BIPQ score (β = 0.40 [95% CI, 0.34-0.45]), higher health literacy score (β = 0.70 [95% CI, 0.62-0.78]), and media use (β = 0.49 [95% CI, 0.41-0.57]) were all associated with high acceptance of gene therapy, while a higher EQ-5D-5L score was associated with lower acceptance (β = -0.29 [95% CI, -0.47 to -0.11]). For older people, being in debt, not having health insurance, and the EQ-5D-5L score were uniquely relevant factors. For people with chronic disease, having an undergraduate degree or higher, a diagnosis of cancer, and the BIPQ score were uniquely relevant factors.

Conclusions and Relevance

These results suggest that basic personal information, economic status, health knowledge, and physical health status were the main factors associated with the acceptance of gene therapy. Improving the health literacy of the population and promoting trust in gene therapy may be effective ways to increase the acceptance of gene therapy. Poorer economic levels and worse disease states may reduce the public's willingness to accept gene therapy.

General Practitioners perspectives on infant telomere length screening after a pregnancy complication: a qualitative analysis

BACKGROUND

Pregnancy complications can impact the mother and child's health in the short and longterm resulting in an increased risk of chronic disease later in life. Telomere length is a biomarker of future cardiometabolic diseases and may offer a novel way of identifying offspring most at risk for future chronic diseases.

OBJECTIVE(S)

To qualitatively explore General Practitioners' (GPs) perspectives on the feasibility and uptake for recommending a telomere screening test in children who were born after a pregnancy complication.

METHODS

Twelve semi-structured interviews were conducted with GPs within metropolitan Adelaide, South Australia. Interviews were audio recorded, transcribed verbatim, and analysed for codes and themes.

RESULTS

Two themes were generated: ethical considerations and practical considerations. Ethically, the GP participants discussed barriers including consenting on behalf of a child, parental guilt, and the impact of health insurance, whereas viewing it for health promotion was a facilitator. For practical considerations, barriers included the difficulty in identifying people eligible for screening, maintaining medical communication between service providers, and time and financial constraints, whereas linking screening for telomere length with existing screening would facilitate uptake.

CONCLUSIONS

GPs were generally supportive of potential telomere screening in infants, particularly via a saliva test that could be embedded in current antenatal care. However, several challenges, such as lack of knowledge, ethical considerations, and time and financial constraints, need to be overcome before such a test could be implemented into practice.

Tailoring Magnetite-Nanoparticle-Based Nanocarriers for Gene Delivery: Exploiting CRISPRa Potential in Reducing Conditions

Gene delivery has emerged as a promising alternative to conventional treatment approaches, allowing for the manipulation of gene expression through gene insertion, deletion, or alteration. However, the susceptibility of gene delivery components to degradation and challenges associated with cell penetration necessitate the use of delivery vehicles for effective functional gene delivery. Nanostructured vehicles, such as iron oxide nanoparticles (IONs) including magnetite nanoparticles (MNPs), have demonstrated significant potential for gene delivery applications due to their chemical versatility, biocompatibility, and strong magnetization. In this study, we developed an ION-based delivery vehicle capable of releasing linearized nucleic acids (tDNA) under reducing conditions in various cell cultures. As a proof of concept, we immobilized a CRISPR activation (CRISPRa) sequence to overexpress the pink1 gene on MNPs functionalized with polyethylene glycol (PEG), 3-[(2-aminoethyl)dithio]propionic acid (AEDP), and a translocating protein (OmpA). The nucleic sequence (tDNA) was modified to include a terminal thiol group and was conjugated to AEDP's terminal thiol via a disulfide exchange reaction. Leveraging the natural sensitivity of the disulfide bridge, the cargo was released under reducing conditions. Physicochemical characterizations, including thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the correct synthesis and functionalization of the MNP-based delivery carriers. The developed nanocarriers exhibited remarkable biocompatibility, as demonstrated by the hemocompatibility, platelet aggregation, and cytocompatibility assays using primary human astrocytes, rodent astrocytes, and human fibroblast cells. Furthermore, the nanocarriers enabled efficient cargo penetration, uptake, and endosomal escape, with minimal nucleofection. A preliminary functionality test using RT-qPCR revealed that the vehicle facilitated the timely release of CRISPRa vectors, resulting in a remarkable 130-fold overexpression of pink1. We demonstrate the potential of the developed ION-based nanocarrier as a versatile and promising gene delivery vehicle with potential applications in gene therapy. The developed nanocarrier is capable of delivering any nucleic sequence (up to 8.2 kb) once it is thiolated using the methodology explained in this study. To our knowledge, this represents the first MNP-based nanocarrier capable of delivering nucleic sequences under specific reducing conditions while preserving functionality.

A comprehensive qualitative framework for health-related quality of life in Duchenne muscular dystrophy

PURPOSE

Duchenne muscular dystrophy (DMD) is a rare x-linked neuromuscular condition predominantly affecting boys and men. There is a paucity of research qualitatively detailing the lived experience of health-related quality of life (HRQoL) for people with DMD. The aim of this study was to identify a comprehensive framework for better understanding HRQoL in DMD.

METHODS

Eighteen boys and men (aged 7 to ≥ 40 years) with DMD were recruited from charity Duchenne UK, a DMD support group, and 5 UK National Health Service Trusts. Semi-structured interviews were conducted using a topic guide informed by a review into HRQoL in DMD. Generic, preference-based, patient-reported outcome measures (PROs) were used as prompts. Interviews were audio recorded, transcribed verbatim and analysed using framework analysis.

RESULTS

Thirty-seven themes were coded, within seven categories. Six categories were conceptualised as components of HRQoL (autonomy, daily activities, feelings and emotions, identity, physical aspects, social relationships) and one considered an input (healthcare, support, and environment). Three additional themes were used to code feedback on the generic PROs (CHU-9D, EQ-5D, HUI). Social relationships received most coverage in the data and was noted as an omission from the PROs.

CONCLUSION

A 30-item framework for HRQoL in DMD has been developed, which was used as input into a new condition-specific HRQoL PRO and preference-based measure: the DMD-QoL. The data has value in its own right in highlighting the lived experience of HRQoL for people with DMD and as a barometer for assessing the content of HRQoL PROs for use in DMD.

Experiences surrounding the diagnostic process and care among parents of children diagnosed with Phelan-McDermid syndrome: A qualitative study

AIM

To explore the experience of parents of children diagnosed with Phelan-McDermid syndrome (PMS) with regard to the diagnostic process, treatment, and medical care.

METHOD

A qualitative descriptive study was conducted. Participants were recruited using non-probabilistic purposeful sampling. In total, 32 parents with children with PMS were included. In-depth interviews and researcher field notes were used. An inductive thematic analysis was performed.

RESULTS

Five themes were identified: (1) the 'diagnostic process' describes the diagnostic process and how it is communicated to the parents; (2) 'treatment and expectations' describes the expectations and hopes placed on future treatment; (3) 'family planning' describes how parents deal with genetic counselling when planning to have more children after a diagnosis of PMS; (4) 'the world of disability' describes the entry of parents into an environment of dependency and disability after the diagnosis; (5) 'family's financial situation' highlights the financial difficulties due to the high cost of therapies and daily care products.

INTERPRETATION

Our results provide insight on how a diagnosis of PMS and its consequences are experienced by parents of children with PMS. These results can be used by health professionals to help and support parents.

Perspectives, Expectations, and Concerns of European Patient Advocates on Advanced Therapy Medicinal Products

This paper presents the results of a qualitative study based on semi-structured interviews of 10 expert patient advocates on several different issues around Advanced Therapy Medicinal Products (ATMPs). The interviews were conducted between February and May 2020 based on a guideline with a list of 8 topics that covered concerns about safety and ethics, access problems and limitations, pricing of ATMPs and educational needs for patient communities. Overall, the interviewees expressed a high degree of convergence of opinions on most of the topics and especially on the identification of the reasons for concern. Conversely, when asked about possible solutions, quite a wide range of solutions were proposed, although with many common points. However, it highlights that the debate is still in its infancy and that there are not yet consolidated positions across the whole community. A general concern emerging from all the interviews is the potential limitation of access to approved ATMPs, both due to the high prices and to the geographical concentration of treatment centers. However, patients recognize the value of a model with a limited number of specialized clinical centers administering these therapies. On the ethical side, patients do not show particular concern as long as ATMPs and the underlying technology is used to treat severe diseases. Finally, patients are asking for both more education on ATMPs as well as for a more continuous involvement of patient representatives in the whole “life-cycle” of a new ATMP, from the development phase to the authorization, from the definition of the reimbursement scheme to the collection of Real Word Data on safety and long-term efficacy of the treatment.

Patients' and caregivers' maximum acceptable risk of death for non-curative gene therapy to treat Duchenne muscular dystrophy

BACKGROUND

Gene therapy offers an etiologically targeted treatment for genetic disorders. Little is known about the acceptance of mortality risk among patients with progressive, fatal conditions. We assessed patients' and caregivers' maximum acceptable risk (MAR) of mortality for gene therapy when used to treat Duchenne muscular dystrophy (DMD).

METHODS

The threshold technique was used to assess tolerance for mortality risks using a hypothetical vignette. Gene therapy was described as non-curative and resulting in a slowing of progression and with a 10-year benefit duration. MAR was analyzed using interval regression for gene therapy initiated "now"; in the last year of walking well; in the last year of being able to bring arms to mouth; and in newborns (for caregivers only).

RESULTS

Two hundred eighty-five caregivers and 35 patients reported the greatest MAR for gene therapy initiated in last year of being able to lift arms (mean MAR 6.3%), followed by last year of walking well (mean MAR 4.4%), when used "now" (mean MAR 3.5%), and when used in the newborn period (mean MAR 2.1%, caregivers only). About 35% would accept ≥200/2000 risk in the last year of being able to lift arms. Non-ambulatory status predicted accepting 1.8 additional points in MAR "now" compared with ambulatory status (p = 0.010). Respondent type (caregiver or patient) did not predict MAR.

CONCLUSION

In this first quantitative study to assess MAR associated with first-generation DMD gene therapy, we find relatively high tolerance for mortality risk in response to a non-curative treatment scenario. Risk tolerance increased with disease progression. Patients and caregivers did not have significantly different MAR. These results have implications for protocol development and shared decision making.

Parental perspectives on gene therapy for children with haemophilia: The Exigency study

INTRODUCTION

Gene therapy is used in life-limiting conditions of childhood. While not a current therapeutic option for children with haemophilia, it may be considered in the future especially for those where access to treatment is limited.

AIM

To assess the attitudes and opinions of parents of children with haemophilia about gene therapy as a potential future treatment, by understanding their awareness about gene therapy and what they need to know now and in the future; gauging levels of interest in gene therapy for their children; and exploring perceived current motivations and barriers.

METHODS

A mixed methods study with an online questionnaire and in-depth qualitative interviews in focus groups which were analysed using thematic analysis.

RESULTS

One hundred and fifty-eight participants commenced the online survey; 63 were fully completed (39%). 60 had heard of gene therapy but few (17/60 [28.3%]) felt they had a good understanding. 38/60 (63.3%) respondents did not know that gene therapy is not available for children. However, most held positive views: 53/60 (88.3%) saying they would consider it for their child. In the interviews, participants (N = 10, all mothers) discussed their awareness and understanding of gene therapy and opinions about it for children, including how this should be communicated to the child and parents.

CONCLUSION

A coherent, community-wide strategy for communicating information and news about gene therapy should now be provided for children and families living with haemophilia. This should come primarily from trusted haemophilia nursing teams, who can give tailored, age-appropriate, factual advice.

Gene therapy in Duchenne muscular dystrophy: Identifying and preparing for the challenges ahead

•

Despite the burden of gene therapy trials for DMD patients there is great enthusiasm.

•

Collaborating with relevant bodies (pharmacy) at an early stage can accelerate progress.

•

A hub and spoke model may be an option for delivering clinical trials and follow up care.

Stem Cell Aging in Skeletal Muscle Regeneration and Disease

Skeletal muscle comprises 30-40% of the weight of a healthy human body and is required for voluntary movements in humans. Mature skeletal muscle is formed by multinuclear cells, which are called myofibers. Formation of myofibers depends on the proliferation, differentiation, and fusion of muscle progenitor cells during development and after injury. Muscle progenitor cells are derived from muscle satellite (stem) cells (MuSCs), which reside on the surface of the myofiber but beneath the basement membrane. MuSCs play a central role in postnatal maintenance, growth, repair, and regeneration of skeletal muscle. In sedentary adult muscle, MuSCs are mitotically quiescent, but are promptly activated in response to muscle injury. Physiological and chronological aging induces MuSC aging, leading to an impaired regenerative capability. Importantly, in pathological situations, repetitive muscle injury induces early impairment of MuSCs due to stem cell aging and leads to early impairment of regeneration ability. In this review, we discuss (1) the role of MuSCs in muscle regeneration, (2) stem cell aging under physiological and pathological conditions, and (3) prospects related to clinical applications of controlling MuSCs.