Burden-of-illness and cost-driving factors in Dravet syndrome patients and carers: A prospective, multicenter study from Germany

The emotional burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy: A qualitative study in Japan

INTRODUCTION

Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare, childhood-onset conditions associated with severe, treatment-resistant epilepsy and developmental issues, including motor and cognitive impairment. Tuberous sclerosis complex (TSC) is a rare genetic disease commonly associated with epilepsy and other neuropsychiatric disorders. This cross-sectional, interview-based study examined the qualitative impact of caring for patients with LGS, DS, and TSC-associated epilepsy on caregivers in Japan, from the perspective of both caregivers and physicians.

METHODS

The survey included a pre-interview worksheet to describe caregivers' emotional journeys, followed by a ≤ 60-minute one-on-one interview. Eligible participants were Japanese caregivers of patients with LGS, DS, or TSC treated for epilepsy symptoms, and Japan-residing pediatricians or neurologists treating ≥ 3 patients with LGS, DS, and/or TSC. Interview question responses were subjected to content analysis to identify the most common response tendencies and themes.

RESULTS

Twenty-six caregivers responded (mean [standard deviation (SD)] age, 45.9 [9.5] years; age range 29-68; 92 % female), caring for patients with LGS (n = 5), DS (n = 10), and TSC (n = 11); patient mean (SD) age, 13.6 (10.0) years; age range 2-44; 27 % adults; 50 % female. Nineteen physicians, treating patients with LGS (n = 9), DS (n = 7), and TSC (n = 10), participated. Caregivers and physicians generally aligned on the factors affecting caregivers' emotional states / quality of life (QoL). The most frequently reported caregiver emotions at the time of diagnosis were shock and discouragement, anxiety for the future, and relief at receiving a diagnosis. Negative emotions throughout disease progression up until the time of survey were mainly caused by worsening of seizures, burden of constant caregiving / lack of free time, and patient's developmental issues. Positive emotions were linked to effective treatment / reduced seizures; more free time owing to the use of facilities, services, or other caregiving support; and developmental progress. Physicians acknowledged that caregivers required consultation services to support their emotional needs. In terms of unmet needs, caregiver and physician responses were aligned on the insufficient availability of services/facilities, the lack of effective treatments, and the uncertainties of adult patient care.

CONCLUSIONS

Caregivers of patients with LGS, DS, or TSC-associated epilepsy in Japan reported a high degree of emotional burden related to frequent seizures, developmental issues, and constant caregiving. The burden of suboptimal treatment effectiveness, limited access to support services, and uncertainties in long-term care emphasize important unmet treatment needs.

A tool for Dravet syndrome-associated neuropsychiatric comorbidities evaluation (DANCE)

BACKGROUND

Dravet syndrome (DS) is a rare and severe form of epilepsy that begins in infancy, which is primarily caused by pathogenic variants in the SCN1A gene. DS is characterized by prolonged and frequent drug-resistant seizures, as well as developmental delays and behavioral problems. The identification of these comorbidities is based on clinical interview and relies on healthcare professionals (HCPs) experience.

METHODS

We assembled a group of expert HCPs and caregivers to create a screening checklist for assessing DS-Associated Neuropsychiatric Comorbidities (DANC). The checklist includes questions related to cognitive and psychiatric domains, motor skills, and the impact of DS on families' daily lives. We administered the checklist to 24 caregivers of DS patients from Belgium, France, and Spain. After piloting, we obtained feedback from expert HCPs and caregivers to refine the checklist.

RESULTS

DS patients showed a wide array of neuropsychiatric symptoms related to DS. The most common cognitive domains reported were attention difficulties and multitasking problems (18/24 caregivers), and impulsivity (17/24), while the most common psychiatric symptoms were temper tantrums (14/24), mood swings (13/24) and autism spectrum disorder (12/24). Balance and coordination problem have been reported in almost all patients with a statement of only 4/23 with complete mobility. Most patients were dependent on others for self-care and eating, and presented sleeping disturbances. Caregivers reported high levels of stress in the family unit, both between siblings and parents. Results show that the main concerns of parents were the behavior and the cognition of the person with DS. The quantitative feedback results showed good-to-very good scores on usefulness, ease of completion, clarity and comprehensiveness of the checklist.

CONCLUSIONS

This pilot study suggests that the DANCE checklist could be a useful screening tool in daily practice for neuropsychiatric comorbidities facilitating their diagnosis and treatment, and empowering both caregivers and patients.

Cost Effectiveness of Adding Fenfluramine to Standard of Care for Patients with Dravet Syndrome in Sweden

OBJECTIVE

This study evaluated, in a Swedish setting, the cost effectiveness of fenfluramine (FFA) as an add-on to standard of care (SoC) for reducing seizure frequency in Dravet syndrome, a severe developmental epileptic encephalopathy.

METHODS

Cost effectiveness of FFA+SoC compared with SoC only was evaluated using a patient-level simulation model with a lifetime horizon. Patient characteristics and treatment effects, including convulsive seizures, seizure-free days and mortality, were derived from FFA clinical trials. Resource use and costs included cost of drug acquisition, routine care and monitoring, as well as ongoing and emergency resources. Quality of life (QoL) estimates for patients and their caregivers were derived from clinical trial data. Robustness was evaluated by one-way sensitivity analysis, probabilistic sensitivity analysis and scenario analyses.

RESULTS

Lifetime cost of FFA+SoC was ~3 million SEK per patient compared with ~1.5 million SEK for SoC only. FFA+SoC generated 15% more QALYs than SoC only (21.2 vs 18.5 over a lifetime), resulting in an incremental cost-effectiveness ratio (ICER) of ~540,000 SEK. Moreover, FFA+SoC had a higher probability of being cost effective than SoC only from a willingness-to-pay threshold of 710,000 SEK. Results remained generally consistent across scenario analyses, with only few exceptions (exclusions of carer utility or FFA effect on sudden unexpected death in epilepsy).

CONCLUSION

Due to better seizure control, FFA is a clinically meaningful add-on therapy and was estimated to be a cost-effective addition to current SoC for patients with this rare disease in Sweden at a willingness-to-pay threshold of 1,000,000 SEK.

Caregiver perceptions of the impact of Dravet syndrome on the family, current supports and hopes and fears for the future: A qualitative study

BACKGROUND

Dravet syndrome (DS) is a Developmental and Epileptic Encephalopathy (DEE) with onset typically in infancy. Seizures are pharmaco-resistant, and neurodevelopment is compromised in almost all children. There is limited data on the impact of the condition on the family, support needs and hopes and fears in Sweden.

METHODS

Interviews were undertaken with the caregivers of 36 of 48 (75%) living children with DS in Sweden focusing on the perceived impact on the family, current supports and hopes and fears for the future. Data from the interviews were analyzed by two raters using reflexive thematic analysis.

RESULTS

The analysis revealed seven main themes focusing on the perceived negative impact the disease has on caregivers and family functioning. These negative impacts concerned: caregiver sleep (e.g., frequent night waking), siblings (e.g., gets less attention/time), social life (e.g., limited vacations), family finances (e.g., limited career progression), parental health (both mental and physical) and need for constant supervision (e.g., child's need for constant supervision for fear of seizures). Another theme concerned the impact on family relationships. Whilst some caregivers perceived the impact to be negative (e.g., limited time for each other) others felt that having a child with DS lead to stronger relationships and more 'teamwork'. With respect to supports, the caregivers identified a number of areas where they felt the family could access appropriate supports. Themes regarding supports included: support from the wider family and friends, support from DS support groups (online or in-person), support from the child's hospital or disability service and respite care (e.g., child was looked after on weekends or had paid carers in the home). Regarding hopes and fears for the future, responses focused mainly on fears, including concerns about premature death of the child, transition to adult healthcare services and care arrangements for child when parents are dead. Hopes for the future included better treatment for epilepsy and associated neurodevelopmental problems and finding a cure for DS.

CONCLUSIONS

Caregivers of children with DS report that the disease can have a very comprehensive negative impact on caregiver and family functioning. Identifying and providing the supports to ameliorate these negative impacts is vital to optimize caregiver and family wellbeing and quality of life.

Invisible patients in rare diseases: parental experiences with the healthcare and social services for children with rare diseases. A mixed method study

This study explores the experiences of Polish caregivers of children with rare disease (CRD) with health care and social services for CRD. A mixed-methods approach was employed, using an open-ended questionnaire with a convenience sample. Quantitative data presented through descriptive statistics, were complemented by thematic analysis applied to qualitative responses. Responses from 925 caregivers of 1002 children with CRD revealed that the duration of the diagnostic journey varied, spanning from 0 to 18 years, with an average time of 1.7 years. Similarly, the average number of physicians consulted before receiving the correct diagnosis was 4.8. The Internet was basic source of information about children's disease. Although caregivers were to some extent satisfied with the quality of health care for CRD, they complained at the accessibility of health care and social services, physicians' ignorance regarding RDs, the lack of co-ordinated care and financial and psychological support. To break the cycle of the diagnostic and therapeutic odyssey that may aggravate the condition of CRD, cause parental stress and financial burden there is a need to change our view on CRD from cure to family-oriented care. Multifaceted challenges and needs of CRD families should be prioritized.

A quantitative cross-sectional study of the burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy in Japan

INTRODUCTION

Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC)-associated epilepsy are rare conditions associated with severe childhood-onset epilepsy. Caregivers play a critical role in the patients' care and may experience significant psychosocial and socioeconomic burden. This cross-sectional study determined the burden of caring for patients with these rare epilepsy conditions in Japan.

METHODS

A quantitative online survey was used to assess patients' and caregivers' characteristics and the caregivers' emotional state, among others. Several validated questionnaires were used: the Hospital Anxiety and Depression Scale (HADS; 0-21 score) assessed the caregivers' emotional wellbeing, the Pediatric Quality of Life Inventory Family Impact Module (PedsQL FIM; 0-100 score) assessed the health-related quality of life (HRQoL) of the caregivers and their families, and the Work Productivity and Activity Impairment General Health (WPAI:GH; 0-100 % score) questionnaire assessed work productivity.

RESULTS

A total of 36 caregivers responded (median [interquartile range (IQR)] age 43.5 [39.5, 48.3] years; 33/36 [92 %] female; 13/36 [36 %] working part-time and 13/36 [36 %] not working). Participants cared for 7/36 (19 %), 19/36 (53 %), and 10/36 (28 %) patients with LGS, DS, and TSC, respectively (median [IQR] age, 11.0 [6.8, 16.3] years; age at first seizure, 0 [0, 0] years). Patients received a median (IQR) of 4 (3, 5) treatment drug types. Patients experienced median (IQR) 3.0 (0, 21.0) epileptic seizures in the previous week; 28/36 (78 %) had severe intellectual disabilities, and 34/36 (94 %) had developmental delays. Caregivers reported stress (17/36 [47 %]), sleep problems (13/36 [36 %]), and anxiety (12/36 [33 %]). They spent a median (IQR) of 50.0 (17.5, 70.0) hours caregiving in the previous week, with 3.0 (1.0, 11.0) hours of seizure-specific care. Caregivers reported that their lives would be easier with a median (IQR) of 1.5 (0, 5.0) hours fewer per week caring for patients during/following seizures. Median HADS scores were 9.5 ('suspected anxiety diagnosis') and 7.5 ('no depression') for caregivers, and PedsQL FIM Total median score was 60.1, indicating HRQoL impairment for the caregiver and their family. WPAI:GH scores for paid workers indicated important work impairment. Higher caregiving hours (≥ 21 h vs. < 21 h in the previous week) resulted in higher caregiver burden as indicated by the HADS Total score (p = 0.0062) and PedsQL FIM Total score (p = 0.0007).

CONCLUSIONS

Caregivers of patients with LGS, DS, or TSC in Japan experience a significant time burden, reduced HRQoL, and high level of work/activity impairment. Caregivers provide round-the-clock care to patients and rely on family and specialized caring services to help manage the increased caregiving time, which tends to be associated with greater emotional burden and HRQoL impact.

Characterizing emergency department and inpatient health care utilization after seizure-related hospitalization: A retrospective cohort study

OBJECTIVE

Seizure care is a significant driver of health care costs in both emergency department (ED) and inpatient settings, but the majority of studies have focused on inpatient admissions as the only metric of health care utilization. This study aims to better characterize ED and inpatient encounters among patients with seizure to inform care and policy.

METHODS

Using statewide administrative data from the Healthcare Cost and Utilization Project State Inpatient Databases and State Emergency Department Databases from Florida and New York, we identified patients with a seizure-related index hospitalization between January 1, 2016, and December 31, 2018. Among this cohort, we examined the incidence and characteristics of subsequent acute care visits in the ED and inpatient settings for 365 days after initial hospital discharge.

RESULTS

A total of 54 456 patients had an eligible seizure-related hospitalization. Patients were 49% female, predominantly White (64%) and non-Hispanic (84%), and used a public primary payer (68%). There were 36 838 (68%) patients with at least one acute care visit in the year following discharge. Overall, patients had a median of 2 (interquartile [IQR] = 1-5) subsequent acute care visits and the median time to first acute care visit was 53 days (IQR = 15-138). Of the 154 369 subsequent acute care visits, 97 399 (63%) were ED-only visits, 56 970 (37%) were readmissions, and 37 176 (24%) were seizure-related. There were 18 786 patients (35%) with four or more acute care visits over 365 days of follow-up. Patients with four or more visits contributed 84% of acute care visits and 78% of costs after initial hospitalization.

SIGNIFICANCE

The majority of patients hospitalized for seizure return to the ED or hospital at least once in the year after discharge. A small portion of patients account for the majority of ED and inpatient visits as well as health care costs associated with this population, identifying a subgroup of patients who may benefit from improved inpatient and outpatient management.

A European pilot study in Dravet Syndrome to delineate what really matters for the patients and families

We aimed to identify caregivers' opinions on the outcome measures that matter in clinical trials in individuals with Dravet syndrome (DS). We conducted a prospective European multicenter study based on an 11 closed questions survey developed by the French reference center for rare epilepsies and DS patients' advocacy groups. Items included questions on seizures and daily life outcomes that a clinical trial on a therapy for individuals with DS should target. Statistical analyses were performed to evaluate the impact of the country of residence and of the patients' age. The survey was answered by 153 caregivers (68%: France, 28%: Germany, and 24%: Italy) off individuals with DS. Individuals with DS included 86 males (mean age of 11.4 [interquartile: 7-20.4] years). Families ranked as important almost all the items proposed. However, items related to daily life had the highest rank in all three countries compared to items about seizures (P = 0.02). Increase in individuals' age was associated with a higher age at diagnosis (ρ = 0.26, P = 0.02), and a lower impact of seizure duration (ρ = -0.25, P = 0.005) and on the need of hospital referral (ρ = -0.26, P = 0.005). These data can help tailor patient-centered outcome measures in future clinical and real-life trials for DS.

Methods used to account for caregivers' sex and gender within studies examining the financial burden of caregivers of children and adolescents : Results from a scoping review

Background

Interest in the financial burden of informal caregivers has been growing. Unfortunately, it remains unclear which method(s) should be used when quantifying this burden.

Purpose

We conducted a scoping review aimed at identifying which methods have been used to conduct such work and quantified their performance. We were also interested in examining how sex and gender considerations were considered within selected studies.

Data Sources

Using a standardized approach, we identified studies published between 2012 and 2022 that aimed to document the financial burden of caregivers to child and adolescent patients. Our search strategy was applied to the MEDLINE, Embase, CINHAL, and Academic Search Premier databases.

Study Selection

Manuscript selection was performed by pairs of reviewers.

Data Extraction

Data extraction was performed by one reviewer with a second reviewer performing quality control. Results were reported using a narrative approach.

Data Synthesis

We identified 9801 unique citations, of which 200 were included in our review. Selected studies covered various disease area (eg, infection/parasitic diseases [n = 31, 16%]) and included quantitative (n = 180, 90%), qualitative (n = 4, 2%) and mixed study designs (n = 16, 8%). Most studies (n = 182, 91%) used questionnaires/surveys, either alone or in combination with other methods, to assess caregivers' financial burden. Less than half (n = 93, 47%) of studies reported on caregivers' sex and none reported on their gender.

Conclusion

We conducted an unrestricted review of published studies examining caregiver's financial burden which allowed us to identify general methodological trends observed in this literature. We believe this work may help improve future studies focusing on this important issue.

Long-term predictors of developmental outcome and disease burden in SCN1A-positive Dravet syndrome

Dravet syndrome is a severe infantile onset developmental and epileptic encephalopathy associated with mutations in the sodium channel alpha 1 subunit gene SCN1A. Prospective data on long-term developmental and clinical outcomes are limited; this study seeks to evaluate the clinical course of Dravet syndrome over a 10-year period and identify predictors of developmental outcome. SCN1A mutation-positive Dravet syndrome patients were prospectively followed up in the UK from 2010 to 2020. Caregivers completed structured questionnaires on clinical features and disease burden; the Epilepsy & Learning Disability Quality of Life Questionnaire, the Adaptive Behavioural Assessment System-3 and the Sleep Disturbance Scale for Children. Sixty-eight of 113 caregivers (60%) returned posted questionnaires. Developmental outcome worsened at follow-up (4.45 [SD 0.65], profound cognitive impairment) compared to baseline (2.9 [SD 1.1], moderate cognitive impairment, P < 0.001), whereas epilepsy severity appeared less severe at 10-year follow-up (P = 0.042). Comorbidities were more apparent at 10-year outcome including an increase in autistic features (77% [48/62] versus 30% [17/57], χ2 = 19.9, P < 0.001), behavioural problems (81% [46/57] versus 38% [23/60], χ2 = 14.1, P < 0.001) and motor/mobility problems (80% [51/64] versus 41% [24/59], χ2 = 16.9, P < 0.001). Subgroup analysis demonstrated a more significant rise in comorbidities in younger compared to older patients. Predictors of worse long-term developmental outcome included poorer baseline language ability (P < 0.001), more severe baseline epilepsy severity (P = 0.003) and a worse SCN1A genetic score (P = 0.027). Sudden unexpected death in epilepsy had not been discussed with a medical professional in 35% (24/68) of participants. Over 90% of caregivers reported a negative impact on their own health and career opportunities. Our study identifies important predictors and potential biomarkers of developmental outcome in Dravet syndrome and emphasizes the significant caregiver burden of illness. The negative impact of epilepsy severity at baseline on long-term developmental outcomes highlights the importance of implementing early and focused therapies whilst the potential impact of newer anti-seizure medications requires further study.

Non-pharmacological therapeutic needs in people with Dravet syndrome

Dravet syndrome (DS) is a genetic rare disease, which is usually caused by a mutation in the SCN1A gene. DS is characterised by a drug-resistant epilepsy and by cognitive and behavioural disturbances. Thus, DS patients require both pharmacological and non-pharmacological treatments. However, there is a paucity of studies on non-pharmacological therapies and their potential benefits. The main aim of this study was to describe the non-pharmacological therapy modalities received by DS patients and their socio-economic impact on the family. Thus, we designed an online survey addressed to caregivers of DS patients. Our results indicated that up to 91.9% of the surveyed patients required non-pharmacological therapies, which were mainly directed to treat cognitive, sensory and motor impairments. In many cases, the economic costs of these therapies were borne entirely by the families. Nevertheless, patients required a deployment of resources not only at a health care level, but also at an educational level.

Critical incidents, nocturnal supervision, and caregiver knowledge on SUDEP in patients with Dravet syndrome: A prospective multicenter study in Germany

OBJECTIVE

The aim was to investigate the monitoring, interventions, and occurrence of critical, potentially life-threatening incidents in patients with Dravet syndrome (DS) and caregivers' knowledge about sudden unexpected death in epilepsy (SUDEP).

METHODS

This multicenter, cross-sectional study of patients with DS and their caregivers in Germany consisted of a questionnaire and prospective diary querying the disease characteristics and demographic data of patients and caregivers.

RESULTS

Our analysis included 108 questionnaires and 82 diaries. Patients with DS were 49.1% male (n = 53), with a mean age of 13.5 (SD ± 10.0 years) and primary caregivers were 92.6% (n = 100) female, with a mean age of 44.7 (SD ± 10.6 years). Monitoring devices were used regularly by 75.9% (n = 82) of caregivers, and most monitored daily/nightly. Frequently used devices were pulse oximeters (64.6%), baby monitors (64.6%), thermometers (24.1%), and Epi-Care (26.8%). Younger caregiver and patient age and history of status epilepticus were associated with increased use of monitoring, and 81% of monitor users reported having avoided a critical incident with nocturnal monitoring. The need for resuscitation due to cardiac or respiratory arrest was reported by 22 caregivers (20.4%), and most cases (72.7%) were associated with a seizure. Caregivers reported frequently performing interventions at night, including oropharyngeal suction, oxygenation, personal hygiene, and change of body position. Most caregivers were well informed about SUDEP (n = 102; 94%) and monitored for a lateral or supine body position; however, only 39.8% reported receiving resuscitation training, whereas 52.8% (n = 57) knew what to do in case the child's breathing or heart activity failed.

SIGNIFICANCE

Critical incidents and the need for resuscitation are reported frequently by caregivers and may be related to high mortality and SUDEP rates in DS. Resuscitation training is welcomed by caregivers and should be continuously provided. Oxygen monitoring devices are frequently used and considered useful by caregivers.

Dravet syndrome: A systematic literature review of the illness burden

We performed a systematic literature review and narrative synthesis according to a pre-registered protocol (Prospero: CRD42022376561) to identify the evidence associated with the burden of illness in Dravet syndrome (DS), a developmental and epileptic encephalopathy characterized by drug-resistant epilepsy with neurocognitive and neurobehavioral impairment. We searched MEDLINE, Embase, and APA PsychInfo, Cochrane's database of systematic reviews, and Epistemonikos from inception to June 2022. Non-interventional studies reporting on epidemiology (incidence, prevalence, and mortality), patient and caregiver health-related quality of life (HRQoL), direct and indirect costs and healthcare resource utilization were eligible. Two reviewers independently carried out the screening. Pre-specified data were extracted and a narrative synthesis was conducted. Overall, 49 studies met the inclusion criteria. The incidence varied from 1:15 400-1:40 900, and the prevalence varied from 1.5 per 100 000 to 6.5 per 100 000. Mortality was reported in 3.7%-20.8% of DS patients, most commonly due to sudden unexpected death in epilepsy and status epilepticus. Patient HRQoL, assessed by caregivers, was lower than in non-DS epilepsy patients; mean scores (0 [worst] to 100/1 [best]) were 62.1 for the Kiddy KINDL/Kid-KINDL, 46.5-54.7 for the PedsQL and 0.42 for the EQ-5D-5L. Caregivers, especially mothers, were severely affected, with impacts on their time, energy, sleep, career, and finances, while siblings were also affected. Symptoms of depression were reported in 47%-70% of caregivers. Mean total direct costs were high across all studies, ranging from $11 048 to $77 914 per patient per year (PPPY), with inpatient admissions being a key cost driver across most studies. Mean costs related to lost productivity were only reported in three publications, ranging from approximately $19 000 to $20 000 PPPY ($17 596 for mothers vs $1564 for fathers). High seizure burden was associated with higher resource utilization, costs and poorer HRQoL. The burden of DS on patients, caregivers, the healthcare system, and society is profound, reflecting the severe nature of the syndrome. Future studies will be able to assess the impact that newly approved therapies have on reducing the burden of DS.

Determining the Relationship Between Seizure-Free Days and Other Predictors of Quality of Life in Patients with Dravet Syndrome and Their Carers from FFA Registration Studies

INTRODUCTION

Dravet syndrome (DS) is a rare, lifelong epileptic encephalopathy characterised by frequent and severe seizures associated with premature mortality. Typically diagnosed in infancy, patients also experience progressive behavioural, motor-function and cognitive decline. Twenty percent of patients do not reach adulthood. Quality of life (QoL) is impaired for both patients and their carers. Reducing convulsive seizure frequency, increasing convulsive seizure-free days (SFDs) and improving patient/carer QoL are primary treatment goals in DS. This study explored the relationship between SFDs and patients' and carers' QoL to inform a cost-utility analysis of fenfluramine (FFA).

METHODS

In FFA registration studies, patients (or their carer proxies) completed the Paediatric QoL inventory (PedsQL). These data were mapped to EuroQol-5 Dimensions Youth version (EQ-5D-Y) to provide patient utilities. Carer utilities were collected using EQ-5D-5L and mapped to EQ-5D-3L to align patient and carer QoL on the same scale. Linear mixed-effects and panel regression models were tested and Hausman tests identified the most appropriate approach for each group. On this basis, a linear mixed-effects regression model was used to examine the relationships between patient EQ-5D-Y and clinically relevant variables (age, frequency of SFDs per 28 days, motor impairments and treatment dose). A linear panel regression model examined the relationship between SFDs and carer QoL.

RESULTS

After adjustment for age and underlying comorbidities, the patient regression model showed that SFDs per 28 days was a significant predictor of QoL. Each additional patient-SFD increased utility by 0.005 (p < 0.001). The carer linear panel model also showed that increasing SFDs per 28 days was a significant predictor of improved QoL. Each additional SFD increased carer utility by 0.014 (p < 0.001).

CONCLUSION

This regression framework highlights that SFDs are significantly correlated with both patients' and carers' QoL. Treatment with effective antiseizure medications that increase SFDs directly improves QoL for patients and their carers.

Caring for Children with Dravet Syndrome: Exploring the Daily Challenges of Family Caregivers

While Polish studies focus on the symptoms, causes and treatment of people suffering from Dravet syndrome (DS), much less is known about the situation of the family caregivers of DS children. This study was designed to explore the experiences, daily challenges and needs related to caring for DS children. An anonymous self-administered online questionnaire was developed. The survey was completed by 75 family caregivers affiliated with the Association for People with Severe Refractory Epilepsy DRAVET.PL on Facebook. Most caregivers felt burdened by their children's reduced mobility (57.3%), mood swings (57.3%), lack of access to rehabilitation and medicine (56%) and healthcare expenses (50.7%). Caregivers also complained of a lack of time to themselves (76%) and work restrictions resulting from caregiving (72%). They consequently reported experiencing fatigue (84%), a deterioration of mental health (60%) and intimacy problems with their spouse/partner (53.4%). An important source of strain was a prolonged diagnostic odyssey and the constant struggle over the healthcare services for DS children. Since DS caregivers' problems and needs are often overlooked, they may be described as the forgotten people in DS. Healthcare professionals should be educated about the challenges related to caring for DS child, psycho-social status and coping resources of DS caregivers, and should focus on identification, monitoring and supporting caregivers' physical and mental well-being and needs.

Sleep quality, anxiety, symptoms of depression, and caregiver burden among those caring for patients with Dravet syndrome: a prospective multicenter study in Germany

BACKGROUND

This study measured sleep quality among caregivers of patients with Dravet syndrome (DS) and assessed the impacts of mental health problems and caregiver burden on sleep quality.

METHODS

This multicenter, cross-sectional study of patients with DS and their caregivers throughout Germany consisted of a questionnaire and a prospective 4-week diary querying disease characteristics, demographic data, living conditions, nocturnal supervision, and caregivers' work situations. Sleep quality was assessed using the Pittsburgh Sleeping Quality Index (PSQI). The Hospital Anxiety and Depression Scale (HADS) and the Burden Scale for Family Caregivers (BSFC) were used to measure anxiety, symptoms of depression, and caregiver burden.

RESULTS

Our analysis included 108 questionnaires and 82 four-week diaries. Patients with DS were 49.1% male (n = 53), with a mean age of 13.5 ± 10.0 years. Caregivers were 92.6% (n = 100) female, with a mean age of 44.7 ± 10.6 years. The overall mean PSQI score was 8.7 ± 3.5, with 76.9% of participants (n = 83) scoring 6 or higher, indicating abnormal sleep quality. The HADS for anxiety and depression had overall mean scores of 9.3 ± 4.3 and 7.9 ± 3.7, respectively; 61.8% and 50.9% of participants scored above the cutoff value of 8 for anxiety and depression, respectively. Statistical analyses revealed caregiver anxiety levels and patients' sleep disturbances as major factors influencing PSQI scores. The overall mean BSFC score of 41.7 ± 11.7 indicates a moderate burden, with 45.3% of caregivers scoring 42 or higher.

CONCLUSIONS

Sleep quality is severely affected among caregivers of patients with DS, correlating with anxiety, comorbidities, and patients' sleep disturbances. A holistic therapeutic approach should be implemented for patients with DS and their caregivers, focusing on the sleep quality and mental health of caregivers.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS), DRKS00016967. Registered 27 May 2019, http://www.drks.de/DRKS00016967.

Emotional experiences of family caregivers of children with Dravet syndrome

BACKGROUND

Since the psychosocial implications of Dravet syndrome (DS) are much more serious and far-reaching than in other types of epilepsy, caring for a DS child seriously affects the entire family. This study describes the emotional experiences of family caregivers of DS children and evaluates the way caregiving affects their perceived quality of life.

METHODS

An anonymous, self-administered online questionnaire was sent to family caregivers of DS children through the online patient advocacy organization the Association for People with Severe Refractory Epilepsy DRAVET.PL. It focussed on the psychosocial impact of caregiving for DS children, the perceived burden of caregiving, caregivers' emotional experiences and feelings related to caregiving, and the impact of DS on the perceived quality of life.

RESULTS

Caregivers stressed that caring for a DS child is associated with a significant psychosocial and emotional burden that affects the entire family. Although most caregivers reported that it was the child's health problems and behavioral and psychological disorders that were the most challenging aspects of caregiving, they were also burdened by the lack of emotional support. As caregivers were profoundly engaged in caregiving, they experienced a variety of distressing emotions, including feelings of helplessness, anxiety and fear, anticipated grief, depression, and impulsivity. Many caregivers also reported that their children's disease disrupted their relationships with their spouses, family, and healthy children. As caregivers reported experiencing role overload, physical fatigue, and mental exhaustion, they stressed the extent to which caregiving for DS children impaired their quality of life, their social and professional life, and was a source of financial burden.

CONCLUSIONS

As this study identified specific burden domains affecting DS caregivers' well-being family carers often need special attention, support, and help. To alleviate the humanistic burden of DS carers a bio-psychosocial approach focusing on physical, mental, and psychosocial interventions should include both DS children and their caregivers.

The burden of illness in Lennox-Gastaut syndrome: a systematic literature review

BACKGROUND

Lennox-Gastaut syndrome (LGS) is a severe developmental and epileptic encephalopathy characterized by drug-resistant epilepsy with multiple seizure types starting in childhood, a typical slow spike-wave pattern on electroencephalogram, and cognitive dysfunction.

METHODS

We performed a systematic literature review according to the PRISMA guidelines to identify, synthesize and appraise the burden of illness in LGS (including "probable" LGS). Studies were identified by searching MEDLINE, Embase and APA PsychInfo, Cochrane's database of systematic reviews, and Epistemonikos. The outcomes were epidemiology (incidence, prevalence or mortality), direct and indirect costs, healthcare resource utilization, and patient and caregiver health-related quality of life (HRQoL).

RESULTS

The search identified 22 publications evaluating the epidemiology (n = 10), direct costs and resource (n = 10) and/or HRQoL (n = 5). No studies reporting on indirect costs were identified. With no specific ICD code for LGS in many regions, several studies had to rely upon indirect methods to identify their patient populations (e.g., algorithms to search insurance claims databases to identify "probable" LGS). There was heterogeneity between studies in how LGS was defined, the size of the populations, ages of the patients and length of the follow-up period. The prevalence varied from 4.2 to 60.8 per 100,000 people across studies for probable LGS and 2.9-28 per 100,000 for a confirmed/narrow definition of LGS. LGS was associated with high mortality rates compared to the general population and epilepsy population. Healthcare resource utilization and direct costs were substantial across all studies. Mean annual direct costs per person varied from $24,048 to $80,545 across studies, and home-based care and inpatient care were significant cost drivers. Studies showed that the HRQoL of patients and caregivers was adversely affected, although only a few studies were identified. In addition, studies suggested that seizure events were associated with higher costs and worse HRQoL. The risk of bias was low or moderate in most studies.

CONCLUSIONS

LGS is associated with a significant burden of illness featuring resistant seizures associated with higher costs and worse HRQoL. More research is needed, especially in evaluating indirect costs and caregiver burden, where there is a notable lack of studies.

Patient profile, management, and quality of life associated with Dravet syndrome: a cross-sectional, multicentre study of 80 patients in Spain

The aim of this study was to describe the profile of patients diagnosed with Dravet syndrome (DS), their clinical management, and the impact of DS on their quality of life (QoL) and family. Data of 80 patients from 11 centres in Spain was collected. Patients (47.5% female) were 12.7 (9.6) years on average (SD, standard deviation). Despite the first episode occurred when patients were a mean (SD) of 0.4 (0.2) years, DS was not diagnosed until they were 6.9 (10.1) years old. The majority (86.7%) had SCN1A gene mutations and 73.4% had seizures during the last year (mostly generalized motor seizures [47.8%]). The mean (SD) number of status epilepticus episodes was 3.6 (8.0) since diagnosis and 0.1 (0.5) in the last year. On the Health Utilities Index Mark (HUI) multi-attribute scale, the mean global score (SD) was 0.56 (0.24) in HUI2 and 0.32 (0.37) in HUI3. The impact of the disease was severe in most patients (HUI2, 81%; HUI3, 83.5%). In the Care-related QoL (CarerQol) the mean (SD) well-being score was 7.2 (2.1). Most caregivers (90%) were satisfied with their caregiving tasks, although 75% had difficulties combining these tasks with daily activities, 68.8% reported mental health problems and 61.2% physical problems.

Psychobehavioural and Cognitive Adverse Events of Anti-Seizure Medications for the Treatment of Developmental and Epileptic Encephalopathies

The developmental and epileptic encephalopathies encompass a group of rare syndromes characterised by severe drug-resistant epilepsy with onset in childhood and significant neurodevelopmental comorbidities. The latter include intellectual disability, developmental delay, behavioural problems including attention-deficit hyperactivity disorder and autism spectrum disorder, psychiatric problems including anxiety and depression, speech impairment and sleep problems. Classical examples of developmental and epileptic encephalopathies include Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. The mainstay of treatment is with multiple anti-seizure medications (ASMs); however, the ASMs themselves can be associated with psychobehavioural adverse events, and effects (negative or positive) on cognition and sleep. We have performed a targeted literature review of ASMs commonly used in the treatment of developmental and epileptic encephalopathies to discuss the latest evidence on their effects on behaviour, mood, cognition, sedation and sleep. The ASMs include valproate (VPA), clobazam, topiramate (TPM), cannabidiol (CBD), fenfluramine (FFA), levetiracetam (LEV), brivaracetam (BRV), zonisamide (ZNS), perampanel (PER), ethosuximide, stiripentol, lamotrigine (LTG), rufinamide, vigabatrin, lacosamide (LCM) and everolimus. Bromide, felbamate and other sodium channel ASMs are discussed briefly. Overall, the current evidence suggest that LEV, PER and to a lesser extent BRV are associated with psychobehavioural adverse events including aggressiveness and irritability; TPM and to a lesser extent ZNS are associated with language impairment and cognitive dulling/memory problems. Patients with a history of behavioural and psychiatric comorbidities may be more at risk of developing psychobehavioural adverse events. Topiramate and ZNS may be associated with negative effects in some aspects of cognition; CBD, FFA, LEV, BRV and LTG may have some positive effects, while the remaining ASMs do not appear to have a detrimental effect. All the ASMs are associated with sedation to a certain extent, which is pronounced during uptitration. Cannabidiol, PER and pregabalin may be associated with improvements in sleep, LTG is associated with insomnia, while VPA, TPM, LEV, ZNS and LCM do not appear to have detrimental effects. There was variability in the extent of evidence for each ASM: for many first-generation and some second-generation ASMs, there is scant documented evidence; however, their extensive use suggests favourable tolerability and safety (e.g. VPA); second-generation and some third-generation ASMs tend to have the most robust evidence documented over several years of use (TPM, LEV, PER, ZNS, BRV), while evidence is still being generated for newer ASMs such as CBD and FFA. Finally, we discuss how a variety of factors can affect mood, behaviour and cognition, and untangling the associations between the effects of the underlying syndrome and those of the ASMs can be challenging. In particular, there is enormous heterogeneity in cognitive, behavioural and developmental impairments that is complex and can change naturally over time; there is a lack of standardised instruments for evaluating these outcomes in developmental and epileptic encephalopathies, with a reliance on subjective evaluations by proxy (caregivers); and treatment regimes are complex involving multiple ASMs as well as other drugs.

Exploring the relationships between composite scores of disease severity, seizure-freedom and quality of life in Dravet syndrome

BACKGROUND

In Dravet syndrome (DS), a rare epileptic and developmental encephalopathy, the effectiveness of a new treatment is predominantly measured in terms of seizure frequency. However, this may not fully capture the impact of a treatment on the broader aspects of the syndrome and patients' health-related quality of life (HRQoL). Using a previously published survey which collected data from DS patients and their carers on the broader manifestations of their syndrome, their HRQoL, and their experience of seizures, this study created composite measures of symptom severity to offer new perspectives on the multifaceted aspects of this rare condition.

METHODS

Survey responses on the severity of physical and psychosocial symptoms were combined with independent assessments of disability and care need, to generate three composite symptom scores assessing the manifestations of DS (physical, psychosocial and care requirements). Variation in HRQoL was investigated in multiple regression analyses to assess the strength of association between each of these composite measures and three forms of seizure measures (seizure frequency, days with no seizures and longest interval without seizures), as experienced over a 4- and 12-week period.

RESULTS

Composite scores were calculated for a cohort of 75 primarily paediatric patients who were enrolled in the study. Strong associations were found between each of the three composite symptom scores and each of the three seizure measures, with the regression coefficient on symptom score highly significant (p ≤ 0.001) in all nine comparisons. Separate regressions using predictors of HRQoL (Kiddy KINDL and Kid KINDL) as the dependent variable were inconclusive, identifying only behavioural/attention problems and status epilepticus as significant predictors of HRQoL.

CONCLUSIONS

These results allow the development of a composite score that may be useful in developing a clinical understanding of the severity of DS for an individual patient and establishing their treatment goals. Where measurement of long-term sequalae of disease is not feasible, such as clinical trials, correlation of the composite score with experience of seizures and seizure-free periods may allow a better contextualisation of the results of short-term assessments.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS), DRKS00011894. Registered 16 March 2017, http://www.drks.de/ DRKS00011894.

The clinical, economic, and humanistic burden of Dravet syndrome - A systematic literature review

Dravet syndrome (DS) is a developmental and epileptic encephalopathy with evolving disease course as individuals age. In recent years, the treatment landscape of DS has changed considerably, and a comprehensive systematic review of the contemporary literature is lacking. Here we synthesized published evidence on the occurrence of clinical impacts by age, the economic and humanistic (health-related quality-of-life [HRQoL]) burden, and health state utility. We provide an evidence-based, contemporary visualization of the clinical manifestations, highlighting that DS is not limited to seizures; non-seizure manifestations appear early in life and increase over time, contributing significantly to the economic and humanistic burden of disease. The primary drivers of HRQoL in DS include seizure severity, cognition, and motor and behavioral problems; in turn, these directly affect caregivers through the extent of assistance required and consequent impact on activities of daily living. Unsurprisingly, costs are driven by seizure-related events, hospitalizations, and in-home medical care visits. This systematic review highlights a paucity of longitudinal data; most studies meeting inclusion criteria were cross-sectional or had short follow-up. Nonetheless, available data illustrate the substantial impact on individuals, their families, and healthcare systems and establish the need for novel therapies to address the complex spectrum of DS manifestations.

Trends in resource utilization and cost of illness in patients with active epilepsy in Germany from 2003 to 2020

OBJECTIVE

To calculate epilepsy-related direct, indirect, and total costs in adult patients with active epilepsy (ongoing unprovoked seizures) in Germany and to analyze cost components and dynamics compared to previous studies from 2003, 2008 and 2013. This analysis was part of the Epi2020 study.

METHODS

Direct and indirect costs related to epilepsy were calculated with a multicenter survey using an established and validated questionnaire with a bottom-up design and human capital approach over a 3-month period in late 2020. Epilepsy-specific costs in the German health care sector from 2003, 2008 and 2013 were corrected for inflation to allow for a valid comparison.

RESULTS

Data on the disease-specific costs for 253 patients in 2020 were analyzed. The mean total costs were calculated at € 5,551 (± € 5,805; median: € 2,611; range: € 274 to € 21,667) per three months, comprising mean direct costs of € 1,861 (± € 1,905; median: € 1,276; range: € 327 to € 13,158) and mean indirect costs of € 3,690 (± € 5,298; median: € 0; range: € 0 to € 11,925). The main direct costs components were hospitalization (42.4%), anti-seizure medication (42.2%) and outpatient care (6.2%). Productivity losses due to early retirement (53.6%), part-time work or unemployment (30.8%) and seizure-related off-days (15.6%) were the main reasons for indirect costs. However, compared to 2013, there was no significant increase of direct costs (-10.0%), and indirect costs significantly increased (p<0.028, +35.1%), resulting in a significant increase in total epilepsy-related costs (p<0.047, +20.2%). Compared to the 2013 study population, a significant increase of cost of illness could be observed (p=0.047).

SIGNIFICANCE

The present study shows that disease-related costs in adult patients with active epilepsy increased from 2013 to 2020. As direct costs have remained constant, this increase is attributable to an increase in indirect costs. These findings highlight the impact of productivity loss caused by early retirement, unemployment, working time reduction and seizure-related days off.

Multicenter, cross-sectional study of the costs of illness and cost-driving factors in adult patients with epilepsy

OBJECTIVE

This study was undertaken to quantify epilepsy-related costs of illness (COI) in Germany and identify cost-driving factors.

METHODS

COI were calculated among adults with epilepsy of different etiologies and severities. Multiple regression analysis was applied to determine any epilepsy-related and sociodemographic factors that serve as cost-driving factors.

RESULTS

In total, 486 patients were included, with a mean age of 40.5 ± 15.5 years (range = 18-83 years, 58.2% women). Mean 3-month COI were estimated at €4911, €2782, and €2598 for focal, genetic generalized, and unclassified epilepsy, respectively. The mean COI for patients with drug-refractory epilepsy (DRE; €7850) were higher than those for patients with non-DRE (€4720), patients with occasional seizures (€3596), or patients with seizures in remission for >1 year (€2409). Identified cost-driving factors for total COI included relevant disability (unstandardized regression coefficient b = €2218), poorer education (b = €2114), living alone (b = €2612), DRE (b = €1831), and frequent seizures (b = €2385). Younger age groups of 18-24 years (b = -€2945) and 25-34 years (b = -€1418) were found to have lower overall expenditures. A relevant disability (b = €441), DRE (b = €1253), frequent seizures (b = €735), and the need for specialized daycare (b = €749) were associated with higher direct COI, and poorer education (b = €1969), living alone (b = €2612), the presence of a relevant disability (b = €1809), DRE (b = €1831), and frequent seizures (b = €2385) were associated with higher indirect COI.

SIGNIFICANCE

This analysis provides up-to-date COI data for use in further health economics analyses, highlighting the high economic impacts associated with disease severity, disability, and disease-related loss of productivity among adult patients with epilepsy. The identified cost drivers could be used as therapeutic and socioeconomic targets for future cost-containment strategies.

A review of fenfluramine for the treatment of Dravet syndrome patients

Introduction

Dravet Syndrome (DS) is a rare epileptiform disorder typically presenting within the first year of life of a normally developing infant. It is characterized by several prolonged seizures that are often resistant to current anti-epileptic drug (AED) regimens. This paper outlines the history and clinical trials of the drug fenfluramine, a drug that when used in addition to AED regimens may provide hope to children affected by DS.

Body

Fenfluramine (3-trifulormethyl-N-ethylamphetamine) is an amphetamine derivative that primarily affects serotonin neurotransmitter levels. It was initially prescribed in the 1960s as an appetite suppressant marketed as a weight loss drug. However, it was removed from the markets due to its association with cardiac valvopathies. It continued to by studied in epilepsy by Gastaut in the 1980s in children with self-induced syncope and irretractable epilepsy. In 2012, Ceulemans et al. studied the use of fenfluramine in patients with DS. Following the success of that retrospective case study, Nabbout et al. and Legae et al. conducted two randomized control trials leading to the FDA approval of fenfluramine under its trade name Fintepla in 2020.

Discussion

The success of the randomized control trials suggests the addition of fenfluramine to current AED regimens may lead to better control of seizures in patients with DS. The side effects of fenfluramine prove to be manageable and the concern for valvopathies has not been reproducible with low dose fenfluramine.

Epidemiology, healthcare resource use, and mortality in patients with probable Dravet syndrome: A population-based study on German health insurance data

OBJECTIVE

Ten-year retrospective study to assess burden of illness in patients with probable Dravet syndrome (DS) identified from German healthcare data.

METHODS

In the absence of an International Classification of Diseases code, patients with probable DS were identified using a selection algorithm considering diagnoses and drug prescriptions. Primary analyses were prevalence and demographics; secondary analyses included healthcare costs, annual hospitalization rate (AHR) and length of stay (LOS), medication use, and mortality.

RESULTS

In the final study year, 64 patients with probable DS (mean [range] age: 33.2 [3-82] years; male: 48%) were identified. Prevalence: 4.7 per 100,000 people. During the study, 160 patients with probable DS were identified and followed up for 1,261 patient-years. Mean cost of healthcare was €11,048 per patient-year (PPY), mostly attributable to inpatient care (47%), medication (26%), and services and devices (19%). Annual healthcare costs were significantly greater for those with prescribed rescue medication (15% of patient-years) vs. without (€16,123 vs. €10,125 PPY, p < 0.001). Mean (standard deviation [SD]) AHR and LOS were 1.1 (1.7) and 17.5 (33.5) days PPY. AHR was significantly greater in patients with prescribed rescue medication vs. without (1.6 [2.0] vs. 1.0 [1.6] PPY, p < 0.001). Mean (SD) number of antiseizure medications prescribed was 2.6 (1.2) PPY and 5.0 (2.5) over the entire observable time for each patient. Mortality rate was significantly higher for probable DS vs. matched controls (11.88% [19 events] vs. 1.19% [172 events], p < 0.001).

CONCLUSION

Probable DS is associated with substantial healthcare costs in Germany.

A Practical Guide to the Treatment of Dravet Syndrome with Anti-Seizure Medication

Dravet syndrome is a severe developmental and epileptic encephalopathy characterised by refractory seizures and cognitive dysfunction. The treatment is challenging, not least because the seizures are highly drug resistant, requiring multiple anti-seizure medications (ASMs), while some ASMs can exacerbate seizures. Initial treatments include the broad-spectrum ASMs valproate (VPA), and clobazam (CLB) in some regions; however, they are generally insufficient to control seizures. With this in mind, three adjunct ASMs have been approved specifically for the treatment of seizures in patients with Dravet syndrome: stiripentol (STP) in 2007 in the European Union and 2018 in the USA, cannabidiol (CBD) in 2018/2019 (in combination with CLB in the European Union) and fenfluramine (FFA) in 2020. These "add-on" therapies (mostly to VPA/CLB) are used as escalation therapies, with the choice dependent on availability in different countries, patient characteristics and caregiver preferences. Topiramate is also frequently used, with evidence of efficacy in Dravet syndrome, and there is anecdotal evidence of efficacy with bromide, which is frequently used in Germany and Japan. With a growing treatment landscape for Dravet syndrome, there can be practical challenges for clinicians, particularly with issues associated with polypharmacy. This practical guide provides an overview of these main ASMs including their indications/contraindications, mechanism of action, efficacy, safety and tolerability profile, dosage requirements, and laboratory and clinical parameters to be evaluated. Standard laboratory and clinical parameters include blood counts, liver function tests, serum concentrations of ASMs, monitoring the growth of children, as well as weight loss and acceleration of behavioural problems. Regular cardiac monitoring is also important with FFA as it has previously been associated with cases of cardiac valve disease when used in adults at high doses (up to 120 mg/day) in combination with phentermine as a therapy for obesity. Importantly, no signs of heart valve disease have been documented to date at the low doses used in patients with developmental and epileptic encephalopathies. In addition, potential drug-drug interactions and their consequences are a key consideration in everyday practice. Interactions that potentially require dosage adjustments to alleviate adverse events include the following: STP + CLB resulting in increased plasma concentrations of CLB and its active metabolite norclobazam may increase somnolence, and an interaction with STP and VPA may increase gastrointestinal adverse events. Cannabidiol has a bi-directional interaction with CLB producing an increase in plasma concentrations of 7-OH-CBD and norclobazam resulting in the potential for increased somnolence and sedation. In addition, CBD is associated with elevations of liver transaminases particularly in patients taking concomitant VPA. The interaction between FFA and STP requires a dose reduction of FFA. Furthermore, concomitant administration of VPA with topiramate has been associated with encephalopathy and/or hyperammonaemia. Finally, we briefly describe other ASMs used in Dravet syndrome, and current key clinical trials.

Rare Neurological Diseases: an Overreview of Pathophysiology, Epidemiology, Clinical Features and Pharmacoeconomic Considerations in the Treating

Rare diseases (RD) are serious chronic diseases affecting small number of people compared to the general population. There are between 6000 and 8000 RDs, which affect about 400 million people worldwide. Drugs used for causal treatment of RDs are called orphan drugs. RDs bear great clinical and economic burden for patients, their families, healthcare systems and society overall. There are at least two reasons for the high cost of treatment of RDs. First, there is no causal therapy for majority of RDs, so exacerbations, complications, and hospitalizations in those patients are common. The second reason is high price of available orphan drugs, which are not cost-effective when traditional pharmacoeconomic evaluation is employed. The pharmacoeconomic aspect of the treatment of RDs is especially important in the field of neurology, since at least one fifth of all RDs is composed of neurological conditions. The aim of this paper was to provide a concise overview of the pathophysiological, epidemiological and clinical characteristics of some of the most important and common rare neurological diseases, with special reference to their impact on society and economy.

Patient and Caregiver Health State Utilities in Lennox-Gastaut Syndrome and Dravet Syndrome

PURPOSE

Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare, treatment-resistant forms of epilepsy characterized by childhood onset of seizures. Cost-effectiveness analysis for new antiseizure medications typically requires health state utilities (HSUs) that reflect the patient and caregiver burden of the relevant conditions. This study aimed to estimate HSUs for LGS and DS. Focus was placed on valuing the impact of seizure frequency and seizure-free days on health-related quality of life (HRQL) for patients and caregivers.

METHODS

Health state vignettes that described the experience of living with and caring for a child with LGS or DS were developed based on a targeted literature review and feedback from interviews with LGS and DS clinical experts and DS caregivers. Vignettes varied by the number of seizures and seizure-free days per month. Twenty-four vignettes were developed that described patient HRQL (6 per condition) and caregiver HRQL (6 per condition) for LGS or DS. Vignettes were evaluated via interviews from the general population in the United Kingdom and Sweden using a visual analog scale and time trade-off (TTO) method. Participants were recruited by interviewers based in different regions of the United Kingdom and Sweden using convenience sampling.

FINDINGS

Two hundred interviews were conducted by video call from March to April 2020. One hundred participants evaluated each of the 6 patient and 6 caregiver vignettes for LGS; a different 100 participants evaluated each of the DS vignettes. The estimated utility values vary consistently according to seizure frequency and number of seizure-free days. Patient TTO utility values range from -0.186 (highest seizure frequency and fewest seizure-free days) to 0.754 (seizure-free state) for LGS and from 0.171 to 0.778 for DS. The caregiver TTO utility values range from 0.032 to 0.810 and 0.510 to 0.881 for LGS and DS, respectively. Fewer seizures and additional seizure-free days are associated with better patient and caregiver HRQL.

IMPLICATIONS

This study estimated utility values for patients with LGS or DS and their caregivers using visual analog scale and TTO valuation among a general public sample. These utility values can be used in cost-effectiveness assessments of new antiseizure medications. The findings indicate the importance of seizure-free days as well as seizure frequency in patient and caregiver HRQL, which may inform the design of future clinical trials.

Health-related quality of life in children and adolescents with tuberous sclerosis complex and their caregivers: A multicentre cohort study from Germany

OBJECTIVE

This study aimed to measure health-related quality of life (HRQOL) in children and adolescents with tuberous sclerosis complex (TSC) and quality of life (QOL) and depressive symptoms among caregivers.

METHODS

Adequate metrics were used to assess HRQOL in children and adolescents with TSC (4-18 years, KINDL^R) as well as QOL (EQ-5D) and symptoms of depression (BDI-II) among caregivers. Predictors for reduced HRQOL and depressive symptoms were identified by variance analysis, ordinal regression, and bivariate correlation.

RESULTS

The mean HRQOL score was 67.9 ± 12.7, and significantly lower values were associated with increasing age, attending special needs education, TSC-associated psychiatric symptoms, and drug-related adverse events. The mean QOL of caregivers was 85.4 ± 15.7, and caregiver's sex, TSC mutation locus, familial TSC clustering, special needs education, degree of disability, care dependency, presence of TSC-associated psychiatric symptoms, and TSC severity were significant predictors of lower QOL. Depressive symptoms were identified in 45.7% of caregivers, associated with female sex of the caregiver, familial TSC clustering, special needs education, and presence of TSC-associated psychiatric symptoms of the child. Multivariate regression analysis revealed adolescence and drug-related adverse events as significant predictors for lower HRQOL in TSC children, and TSC2 variants predicted lower QOL and depressive symptoms in caregivers.

CONCLUSION

Compared with other chronic diseases, such as headache, diabetes or obesity, children with TSC have significantly lower HRQOL, which further decreases during adolescence. A decreased HRQOL of patients correlates with a lower QOL and increased symptoms of depression of their caregivers. These results may improve the comprehensive therapy and care of children and adolescents with TSC and their families and caregivers.

TRIAL REGISTRATION

DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Impact of developmental and epileptic encephalopathies on caregivers: A literature review

OBJECTIVES

Developmental and epileptic encephalopathies (DEEs) are rare neurodevelopmental disorders characterized by early-onset seizures and numerous comorbidities. Due to the complex requirements for the care of a child with a DEE, these disorders would be expected to impact health-related quality of life (HRQL) for caregivers as well as for patients. The objective of this literature review was to describe the impact of DEEs on the HRQL, emotional wellbeing, and usual activities (social, work, relationships, etc.) of caregivers, including the wider impact on other family members such as siblings.

METHODS

A literature search was conducted in May 2020 using MEDLINE® and Embase® databases. Quantitative and qualitative studies were identified using search terms related to family, disease type (including >20 specific DEEs), and quality of life/methodology. Each study was assessed for relevance and was graded using customized critical appraisal criteria. Findings from studies that were given the highest quality ratings were summarized and used to develop a conceptual model to illustrate the complex impact of DEEs on caregiver HRQL.

RESULTS

Sixty-seven relevant studies were identified, of which 39 (27 quantitative, 12 qualitative) met the highest appraisal criteria. The studies recruited caregivers of patients with one of eight individual DEEs, or pediatric intractable or refractory epilepsy. Most studies reported negative impacts on HRQL and emotional wellbeing in caregivers. The wide-ranging impact of a DEE was highlighted by reports of negative effects on caregivers' physical health, daily activities, relationships, social activities, leisure time, work, and productivity. Factors that influenced the perceived impact included demographic characteristics (e.g., child's age, living arrangements, family income) and clinical factors (e.g., feeding or sleep difficulties, disease severity). Few studies evaluated the impact on siblings.

CONCLUSIONS

There is evidence that DEEs can impact HRQL and emotional wellbeing and can limit usual activities for the primary caregiver and their wider family. However, no research was identified regarding many individual DEEs, and only limited research assessed the impact on different family members with most studies focusing on mothers. Further research is required to understand the influence of certain factors such as the age of the patient, disease severity, and seizures on caregiver burden. Furthermore, the review highlighted the lack of appropriate measurement tools to assess caregiver HRQL in this population.

Dravet syndrome: Effects on informal caregivers' mental health and quality of life - A systematic review

BACKGROUND

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy, with predictable negative consequences for informal caregivers' mental health. This systematic review aimed to evaluate the representativeness of depression, anxiety, and burden in these caregivers and assess their quality of life.

METHODS

The PRISMA recommendations were followed, and a comprehensive search was conducted on PubMed/MEDLINE, WoS and Scopus databases, without date or language limits. Only observational quantitative studies on adult informal caregivers of patients with DS were considered.

RESULTS

Of 876 records found, 21 full-text articles were assessed and only 6 met the inclusion criteria. The latter have mostly a cross-sectional design and include samples composed by 19 to 742 caregivers, mainly mothers/females. Most of the study participants had a Bachelor's degree/higher educational level and were married. An important incidence of depression and anxiety on DS caregivers was reported, with significantly higher levels compared with population norms and with carers of other patients with epilepsy. Depression/anxiety were shown to be significantly associated with caregivers' fatigue and compromised sleep quality. Other important aspects of burden have been identified; however, comparisons between studies were not possible as different scales were used. Caregivers' health-related quality of life is also affected, with mothers reporting a worse perception on this domain.

CONCLUSIONS

Mental health and quality of life of DS caregivers are compromised, with mothers bearing an apparently greater burden. Studies using validated instruments for this population to assess the previously considered outcomes are needed, in order to inform the development of preventive strategies and problem-oriented interventions.

Direct and indirect costs and cost-driving factors of Tuberous sclerosis complex in children, adolescents, and caregivers: a multicenter cohort study

BACKGROUND

Tuberous sclerosis complex (TSC), a multisystem genetic disorder, affects many organs and systems, characterized by benign growths. This German multicenter study estimated the disease-specific costs and cost-driving factors associated with various organ manifestations in TSC patients.

METHODS

A validated, three-month, retrospective questionnaire was administered to assess the sociodemographic and clinical characteristics, organ manifestations, direct, indirect, out-of-pocket, and nursing care-level costs, completed by caregivers of patients with TSC throughout Germany.

RESULTS

The caregivers of 184 patients (mean age 9.8 ± 5.3 years, range 0.7-21.8 years) submitted questionnaires. The reported TSC disease manifestations included epilepsy (92%), skin disorders (86%), structural brain disorders (83%), heart and circulatory system disorders (67%), kidney and urinary tract disorders (53%), and psychiatric disorders (51%). Genetic variations in TSC2 were reported in 46% of patients, whereas 14% were reported in TSC1. Mean total direct health care costs were EUR 4949 [95% confidence interval (95% CI) EUR 4088-5863, median EUR 2062] per patient over three months. Medication costs represented the largest direct cost category (54% of total direct costs, mean EUR 2658), with mechanistic target of rapamycin (mTOR) inhibitors representing the largest share (47%, EUR 2309). The cost of anti-seizure drugs (ASDs) accounted for a mean of only EUR 260 (5%). Inpatient costs (21%, EUR 1027) and ancillary therapy costs (8%, EUR 407) were also important direct cost components. The mean nursing care-level costs were EUR 1163 (95% CI EUR 1027-1314, median EUR 1635) over three months. Total indirect costs totaled a mean of EUR 2813 (95% CI EUR 2221-3394, median EUR 215) for mothers and EUR 372 (95% CI EUR 193-586, median EUR 0) for fathers. Multiple regression analyses revealed polytherapy with two or more ASDs and the use of mTOR inhibitors as independent cost-driving factors of total direct costs. Disability and psychiatric disease were independent cost-driving factors for total indirect costs as well as for nursing care-level costs.

CONCLUSIONS

This study revealed substantial direct (including medication), nursing care-level, and indirect costs associated with TSC over three months, highlighting the spectrum of organ manifestations and their treatment needs in the German healthcare setting.

TRIAL REGISTRATION

DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Direct and indirect costs and cost-driving factors in adults with tuberous sclerosis complex: a multicenter cohort study and a review of the literature

Background

Tuberous sclerosis complex (TSC) is a monogenetic, multisystem disorder characterized by benign growths due to TSC1 or TSC2 mutations. This German multicenter study estimated the costs and related cost drivers associated with organ manifestations in adults with TSC.

Methods

A validated, three-month, retrospective questionnaire assessed the sociodemographic and clinical characteristics, organ manifestations, direct, indirect, out-of-pocket (OOP), and nursing care-level costs among adult individuals with TSC throughout Germany from a societal perspective (costing year: 2019).

Results

We enrolled 192 adults with TSC (mean age: 33.4 ± 12.7 years; range: 18–78 years, 51.6% [n = 99] women). Reported TSC disease manifestations included skin (94.8%) and kidney and urinary tract (74%) disorders, epilepsy (72.9%), structural brain defects (67.2%), psychiatric disorders (50.5%), heart and circulatory system disorders (50.5%), and lymphangioleiomyomatosis (11.5%). TSC1 and TSC2 mutations were reported in 16.7% and 25% of respondents, respectively. Mean direct health care costs totaled EUR 6452 (median EUR 1920; 95% confidence interval [CI] EUR 5533–7422) per patient over three months. Medication costs represented the major direct cost category (77% of total direct costs; mean EUR 4953), and mechanistic target of rapamycin (mTOR) inhibitors represented the largest share (68%, EUR 4358). Mean antiseizure drug (ASD) costs were only EUR 415 (6%). Inpatient costs (8%, EUR 518) and outpatient treatment costs (7%; EUR 467) were important further direct cost components. The mean care grade allowance as an approximator of informal nursing care costs was EUR 929 (median EUR 0; 95% CI EUR 780–1083) over three months. Mean indirect costs totaled EUR 3174 (median EUR 0; 95% CI EUR 2503–3840) among working-age individuals (< 67 years in Germany). Multiple regression analyses revealed mTOR inhibitor use and persistent seizures as independent cost-driving factors for total direct costs. Older age and disability were independent cost-driving factors for total indirect costs, whereas epilepsy, psychiatric disease, and disability were independent cost-driving factors for nursing care costs.

Conclusions

This three-month study revealed substantial direct healthcare, indirect healthcare, and medication costs associated with TSC in Germany. This study highlights the spectrum of organ manifestations and their associated treatment needs in the German healthcare setting. Trial registration: DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-021-01838-w.

Prescription patterns of antiseizure drugs in tuberous sclerosis complex (TSC)-associated epilepsy: a multicenter cohort study from Germany and review of the literature

OBJECTIVE

Seizures are a primary and early disease manifestation of Tuberous Sclerosis Complex (TSC). We aimed to describe the age-stratified patterns of antiseizure drug (ASD) treatments among children, adolescents, and adults with TSC in Germany. Additionally, we reviewed real-world and clinical study evidence regarding ASD utilization in patients with TSC.

METHODS

We evaluated the pattern of routine ASD use and everolimus prescriptions based on a 2019 multicenter survey of 268 individuals with TSC-associated epilepsy. We contextualized the results with a structured review of real-world and clinical study evidence.

RESULTS

TSC-associated epilepsy treatment comprises a wide variety of ASDs. In this German sample, the majority of patients were treated with polytherapy, and lamotrigine (34.7%), valproate (32.8%), oxcarbazepine (28.7%), vigabatrin (19.0%), and levetiracetam (17.9%) were identified as the most-commonly used ASDs. In addition, everolimus was used by 32.5% of patients. In adherence to current TSC guidelines, the disease-modifying ASD vigabatrin was widely used in children (58% below the age of 5 years), whereas treatment in adults did not necessarily reflect guideline preference for (partial) GABAergic ASDs.

CONCLUSIONS

The selection of ASDs for patients with TSC-associated epilepsy follows well-evaluated recommendations, including the guidelines regarding vigabatrin use in children. Several characteristics, such as the comparatively high frequency of valproate use and polytherapy, reflect the severity of TSC-associated epilepsy.

Klinische Charakteristika und Lebensqualität beim Dravet-Syndrom: Ergebnisse der deutschen Kohorte des „Dravet syndrome caregiver survey“ (DISCUSS)

Hintergrund

Das Dravet-Syndrom (DS) ist ein seltenes, in der frühen Kindheit beginnendes, therapierefraktäres Epilepsiesyndrom, das mit einer hohen Morbidität und Mortalität verbunden ist.

Fragestellung

Ziele der Querschnittsstudie „Dravet syndrome caregiver survey“ (DISCUSS) sind die Identifizierung und Beschreibung der Faktoren, die einen Einfluss auf die Krankheitslast von Patienten mit DS und ihre Betreuer haben können. Die Ergebnisse der deutschen Kohorte werden vorgestellt.

Material und Methoden

Die Datenerhebung erfolgte durch eine anonyme Befragung von Eltern. Die Ergebnisse wurden für die verschiedenen Altersgruppen statistisch ausgewertet.

Ergebnisse

Der Fragebogen wurde von 68 Eltern der DS-Patienten mit einem durchschnittlichen Alter von 10 Jahren (Median: 9, Spanne: 1–26) ausgefüllt. Nur 3 Patienten (4,4 %) waren in den letzten 3 Monaten anfallsfrei. Insgesamt hatten 97 % der Patienten, die älter als 5 Jahre waren (n = 45), mindestens eine Komorbidität. Die zum Befragungszeitpunkt am häufigsten eingenommenen Antiepileptika waren Valproat, Kaliumbromid, Stiripentol, Clobazam und Topiramat. In der Vergangenheit wurden Natriumkanalblocker, Phenobarbital und Levetiracetam eingesetzt, aktuell fanden diese Antiepileptika nur selten Verwendung. Die Lebensqualität der Patienten war niedriger als die der Allgemeinbevölkerung. Die Erkrankung eines Familienmitglieds mit DS beeinflusst Eltern und Geschwister in hohem Maße.

Diskussion

Trotz individueller Kombinationstherapien sind die meisten Patienten mit DS nicht anfallsfrei. Insgesamt hat sich der Einsatz von beim DS wenig wirksamer Medikamente und der kontraindizierten Natriumkanalblocker zugunsten von wirksameren Medikamenten verschoben. Neue Therapie- und Versorgungskonzepte sind notwendig, um die Versorgung der Patienten mit DS zu verbessern und Eltern und Geschwister zu entlasten.

Epidemiology, healthcare resource use, and mortality in patients with probable Lennox-Gastaut syndrome: A population-based study on German health insurance data

OBJECTIVE

This retrospective study examined patients with probable Lennox-Gastaut syndrome (LGS) identified from German healthcare data.

METHODS

This 10-year study (2007-2016) assessed healthcare insurance claims information from the Vilua Healthcare research database. A selection algorithm considering diagnoses and drug prescriptions identified patients with probable LGS. To increase the sensitivity of the identification algorithm, two populations were defined: all patients with probable LGS (broadly defined) and only those with a documented epilepsy diagnosis before 6 years of age (narrowly defined). This specific criterion was used as LGS typically has a peak seizure onset between age 3 and 5 years. Primary analyses were prevalence and demographics; secondary analyses included healthcare costs, hospitalization rate and length of stay (LOS), medication use, and mortality.

RESULTS

In the final year of the study, 545 patients with broadly defined probable LGS (mean [range] age: 31.4 [2-89] years; male: 53%) were identified. Using the narrowly defined probable LGS definition, the number of patients was reduced to 102 (mean [range] age: 7.4 [2-14] years; male: 52%). Prevalence of broadly defined and narrowly defined probable LGS was 39.2 and 6.5 per 100,000 people. During the 10-year study, 208 patients with narrowly defined probable LGS were identified and followed up for 1379 patient-years. The mean annual cost of healthcare was €22,787 per patient-year (PPY); greatest costs were attributable to inpatient care (33%), home nursing care (13%), and medication (10%). Mean annual healthcare costs were significantly greater for those with prescribed rescue medication (45% of patient-years) versus those without (€33,872 vs. €13,785 PPY, p < 0.001). Mean (standard deviation [SD]) annual hospitalization rate was 1.6 (2.0) PPY with mean (SD) annual LOS of 22.7 (46.0) days. Annual hospitalization rate was significantly greater in those who were prescribed rescue medication versus those who were not (2.2 [2.3] vs. 1.1 [1.6] PPY, p < 0.001). The mean (SD) number of different medications prescribed was 11.3 (7.3) PPY and 33.8 (17.0) over the entire observable time per patient (OET); antiepileptic drugs only accounted for 2.1 (1.1) of the medications prescribed PPY and 3.8 (2.0) OET. Over the 10-year study period, mortality in patients with narrowly defined probable LGS was significantly higher than the matched control population (six events [2.88%] vs. oneevent [0.01%], p < 0.001).

CONCLUSION

Annual healthcare costs incurred by patients with probable LGS in Germany were substantial, and mostly attributable to inpatient care, home nursing care, and medication. Patients prescribed with rescue medication incurred significantly greater costs than those who were not. Patients with narrowly defined probable LGS had a higher mortality rate versus control populations.

The Direct Costs of Dravet's Syndrome before and after Diagnosis Assessment

The objective of this study was to estimate the direct cost before and after diagnosis assessment in patients with Dravet's syndrome (DS). The basis of the economic study was to calculate the costs of health care before and after diagnosis of DS. We retrospectively evaluated all SCN1A positive patients with phenotype of DS treated in our hospital. Statistical analyses were performed by IBM SPSS Statistics 24.0 software. After the diagnosis of DS, there was a significant decline of health care costs (-85.6%) an average of €29.4 ± 26.1 monthly per patient. We estimated the monthly costs at €204.5 ± 167 (median: €193.9, range: €35.5-534.4) per patient before DS diagnosis. The major cost was for hospitalization in neurological department: €43.3 ± 52 (median: €21.9, range: €9.5-179.4) per patient. Minimal cost per patient per months before DS diagnosis was cost of psychological testing/care and complementary rehabilitation (0.13 and 0.6% of total cost). After DS diagnosis, the major cost was focused on nonhospitalization care of patients (64.8%), minimal (€0) for genetic testing and major for outpatient care (18%, mean: €5.3, median: €7). DS results in essential health care utilization and high financial burden before diagnosis elucidation caused by repeated hospitalization and extensive diagnostics tests of "epileptic encephalopathy of unknown etiology." The results of this study point out that early assessment of the diagnosis leads to significant decrease of the financial costs because of adequate therapeutic management and exclusion of redundant diagnostic testing after elucidation of correct diagnosis.

Efficacy, Retention and Tolerability of Everolimus in Patients with Tuberous Sclerosis Complex: A Survey-Based Study on Patients' Perspectives

BACKGROUND

The approval of everolimus (EVE) for the treatment of angiomyolipoma (2013), subependymal giant cell astrocytoma (2013) and drug-refractory epilepsy (2017) in patients with tuberous sclerosis complex (TSC) represents the first disease-modifying treatment option available for this rare and complex genetic disorder.

OBJECTIVE

The objective of this study was to analyse the use, efficacy, tolerability and treatment retention of EVE in patients with TSC in Germany from the patient's perspective.

METHODS

A structured cross-age survey was conducted at 26 specialised TSC centres in Germany and by the German TSC patient advocacy group between February and July 2019, enrolling children, adolescents and adult patients with TSC.

RESULTS

Of 365 participants, 36.7% (n = 134) reported the current or past intake of EVE, including 31.5% (n = 115) who were taking EVE at study entry. The mean EVE dosage was 6.1 ± 2.9 mg/m² (median: 5.6 mg/m², range 2.0-15.1 mg/m²) in children and adolescents and 4 ± 2.1 mg/m² (median: 3.7 mg/m², range 0.8-10.1 mg/m²) in adult patients. An early diagnosis of TSC, the presence of angiomyolipoma, drug-refractory epilepsy, neuropsychiatric manifestations, subependymal giant cell astrocytoma, cardiac rhabdomyoma and overall multi-organ involvement were associated with the use of EVE as a disease-modifying treatment. The reported efficacy was 64.0% for angiomyolipoma (75% in adult patients), 66.2% for drug-refractory epilepsy, and 54.4% for subependymal giant cell astrocytoma. The overall retention rate for EVE was 85.8%. The retention rates after 12 months of EVE therapy were higher among adults (93.7%) than among children and adolescents (88.7%; 90.5% vs 77.4% after 24 months; 87.3% vs 77.4% after 36 months). Tolerability was acceptable, with 70.9% of patients overall reporting adverse events, including stomatitis (47.0%), acne-like rash (7.7%), increased susceptibility to common infections and lymphoedema (each 6.0%), which were the most frequently reported symptoms. With a total score of 41.7 compared with 36.8 among patients not taking EVE, patients currently being treated with EVE showed an increased Liverpool Adverse Event Profile. Noticeable deviations in the sub-items 'tiredness', 'skin problems' and 'mouth/gum problems', which are likely related to EVE-typical adverse effects, were more frequently reported among patients taking EVE.

CONCLUSIONS

From the patients' perspective, EVE is an effective and relatively well-tolerated disease-modifying treatment option for children, adolescents and adults with TSC, associated with a high long-term retention rate that can be individually considered for each patient. Everolimus therapy should ideally be supervised by a centre experienced in the use of mechanistic target of rapamycin inhibitors, and adverse effects should be monitored on a regular basis.

Advances in the design and discovery of novel small molecule drugs for the treatment of Dravet Syndrome

Introduction: Dravet syndrome (severe myoclonic epilepsy in infancy) begins in the first year of life characterized by generalized or unilateral clonic seizures that are frequently triggered by high fever. A subsequent worsening stage occurs (in years 1-4 of life) and seizure activity is accompanied by disturbed psychomotor development. The third stage of the disease, known as the 'stabilization phase,' is associated with seizures and intellectual impairment. Of note, a mutation in the voltage-gated sodium-channel gene α 1 subunit (SCN1A) has been found in around 85% of patients with Dravet syndrome.Areas covered: The authors review the current treatment strategies as well as potential drugs in the initial stages of clinical evaluation. The authors also review drugs with protective activity in mice models of Dravet syndrome.Expert opinion: Experimental data and results from initial clinical studies have brought attention to several drugs with various mechanisms of action including: ataluren (a suppressant of premature stop codons; under clinical evaluation), EPX-100, EPX-200, fenfluramine (serotonin modulators), soticlestat (an 24-hydroxylase cholesterol enzyme inhibitor), SPN-817 (an inhibitor of acetylcholinesterase), verapamil (a voltage-dependent calcium channel inhibitor) and STK-001 (an antisense oligonucleotide). The latter is scheduled for clinical evaluation.

Therapeutic advances in Dravet syndrome: a targeted literature review

INTRODUCTION

Dravet syndrome (DS), a prototypic developmental and genetic epileptic encephalopathy (DEE), is characterized by an early onset of treatment-refractory seizures, together with impairments in motor control, behavior, and cognition. Even with multiple conventional anti-epileptic drugs, seizures remain poorly controlled, and there has been a considerable unmet need for effective and tolerable treatments.

AREAS COVERED

This targeted literature review aims to highlight recent changes to the therapeutic landscape for DS by summarizing the most up-to-date, evidence-based research, including pivotal data from the clinical development of stiripentol, cannabidiol, and fenfluramine, which are important milestones for DS treatment, together with the latest findings of other pharmacotherapies in development. In phase III, double-blind, placebo-controlled randomized controlled trials stiripentol, cannabidiol, and fenfluramine have shown clinically relevant reductions in convulsive seizure frequency, and are generally well tolerated. Stiripentol was associated with responder rates (greater than 50% reduction in convulsive seizure frequency) of 67%-71%, when added to valproic acid and clobazam; cannabidiol was associated with responder rates of 43%-49% (48%-63% in conjunction with clobazam), and fenfluramine of 54%-68% across studies. Therapies in development include soticlestat, ataluren, verapamil, and clemizole, with strategies to treat the underlying cause of DS, including gene therapy and antisense oligonucleotides beginning to emerge from preclinical studies.

EXPERT OPINION

Despite the challenges of drug development in rare diseases, this is an exciting time for the treatment of DS, with the promise of new efficacious and well-tolerated therapies, which may pave the way for treatment advances in other DEEs.

Stiripentol: A Review in Dravet Syndrome

Stiripentol (Diacomit^®) is an orally-active, structurally unique anti-epileptic drug (AED) with multiple potential mechanisms of action, including enhancement of central γ-aminobutyric acid transmission. In the EU, stiripentol is indicated for use in conjunction with clobazam and valproate as adjunctive therapy of refractory generalized tonic-clonic seizures in patients with Dravet syndrome (DS; previously known as severe myoclonic epilepsy of infancy), whose seizures are not adequately controlled with clobazam and valproate. This approval (and similar DS indications in the USA, Canada and Japan), reflect the results of the STICLO studies, two small, randomized controlled trials in which stiripentol as adjunctive therapy was associated with a markedly superior response rate after 2 months compared with placebo in patients aged between 3 and ≈ 21 years with DS that was inadequately controlled with clobazam and valproate. These short-term results have subsequently been supported and extended by findings from longer-term, open-label, observational studies, including a retrospective longitudinal cohort study, which showed that the efficacy of combining stiripentol with clobazam and valproate when started at paediatric age was maintained in mid-adulthood with up to 24 years of exposure, and up to 40 years of age. Drowsiness, appetite loss, weight loss, ataxia and tremor are the most common adverse events associated with the addition of stiripentol to clobazam and valproate. Based on the available evidence, stiripentol, as an adjunct to clobazam and valproate, is a demonstrably beneficial and generally well-tolerated second-line treatment for patients with DS.

Decision Models for Assessing the Cost Effectiveness of Treatments for Pediatric Drug-Resistant Epilepsy: A Systematic Review of Economic Evaluations

BACKGROUND

Drug-resistant epilepsy affects about one-third of children with epilepsy and is associated with high costs to the healthcare system, yet the cost effectiveness of most treatments is unclear. Use of cannabis-based products for epilepsy is increasing, and the cost effectiveness of such strategies relative to conventional pharmacologic treatments must be considered.

OBJECTIVE

The objective of this systematic review was to identify economic evaluations of cannabis-based treatments for pediatric drug-resistant epilepsy. We also sought to identify and appraise decision models that have been used in economic evaluations of pharmacologic treatments (i.e., antiepileptic drugs) in this population.

METHODS

Electronic searches of MEDLINE, EMBASE, and the Cochrane library, as well as a targeted grey literature search, were undertaken (11 June 2018). Model-based full economic evaluations involving cannabis-based treatments or pharmacologic treatments for drug-resistant epilepsy in children were eligible for inclusion. Two independent reviewers selected studies for inclusion, and study quality was assessed by use of the Drummond and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklists. Study findings, as well as model characteristics, are narratively summarized.

RESULTS

Nine economic evaluations involving children with drug-resistant epilepsy were identified; however, none involved cannabis-based treatments. All studies involved pharmacologic treatments compared with other pharmacologic treatments or non-pharmacologic treatments (i.e., ketogenic diet, epilepsy surgery, vagus nerve stimulation). Few studies have assessed the cost effectiveness of pharmacologic treatments in specific drug-resistant epilepsy syndromes, including Dravet and Lennox-Gastaut syndromes. Five included studies involved use of Markov models with a similar structure (i.e., health states based on seizure frequency relative to baseline). There was a wide range of methodological quality, and few studies fully addressed context-specific issues such as weight gain and treatment switching.

CONCLUSION

Whether cannabis-based treatments for pediatric drug-resistant epilepsy represent good value for money has yet to be investigated. Economic evaluations of such treatments are needed and should address issues of particular importance in pediatric epilepsy, including weight gain over time, switching or discontinuation of treatments, effectiveness of interventions and comparators, and long-term effectiveness beyond the duration of available clinical studies.

PROSPERO REGISTRATION

CRD42018099591.

General Trends in Prices and Prescription Patterns of Anticonvulsants in Germany between 2000 and 2017: Analysis of National and Cohort-Based Data

OBJECTIVE

Our aim was to explore trends in price evolution and prescription volumes of anticonvulsants (AEDs, antiepileptic drugs) in Germany between 2000 and 2017.

METHOD

This study used data from annual reports on mean prescription frequency and prices of defined daily doses (DDD) of AEDs in Germany to analyze nationwide trends. Interrupted time series (ITS) analysis was employed to test for significant effects of several statutory healthcare reforms in Germany on AED price evolution. These data were compared to cohort-based prescription patterns of four German cohort studies from 2003, 2008, 2013, and 2016 that included a total of 1368 patients with focal and generalized epilepsies.

RESULTS

Analysis of national prescription data between 2000 and 2017 showed that mean prices per DDD of third-generation AEDs decreased by 65% and mean prices of second-generation AEDs decreased by 36%, whereas mean prices of first-generation AEDs increased by 133%. Simultaneously, mean prescription frequency of third- generation AEDs increased by 2494%, while there was a substantial decrease in the use of first- (- 55%) and second- (- 16%) generation AEDs. ITS analysis revealed that in particular the introduction of mandatory rebates on drugs in 2003 affected prices of frequently used newer AEDs. These findings are consistent with data from cohort studies of epilepsy patients showing a general decrease of prices for frequently used AEDs in monotherapy by 62% and in combination therapies by 68%. The analysis suggests that overall expenses for AEDs remained stable despite an increase in the prescription of "newer" and "non-enzyme-inducing" AEDs for epilepsy patients.

CONCLUSION

Between 2000 and 2017, a distinct decline in AED prices can be observed that seems predominately caused by a governmentally obtained price decline of third- and second-generation drugs. These observations seem to be the result of a German statutory cost containment policy applied across all health-care sectors. The increasing use of third-generation AEDs to the disadvantage of "old" and "enzyme-inducing" AEDs reflects the preferences of physicians and patients with epilepsy and follows national treatment guidelines.

Seizure management and prescription patterns of anticonvulsants in Dravet syndrome: A multicenter cohort study from Germany and review of literature

OBJECTIVE

The aim of this study was to describe the treatment pattern of patients with Dravet syndrome (DS) in Germany with routine antiepileptic drugs (AEDs) and emergency medication, and to review the literature of real-world evidence on medicine utilization of patients with DS in Europe.

METHODS

Patient use of routine AEDs and emergency medications over 3-6 months was analyzed from a 2018 multicenter survey of 93 caregivers of patients with DS throughout Germany. Results were contextualized in a review of real-world evidence on medicine utilization of patients with DS in Europe.

RESULTS

The variety of medications and the most frequent combinations routinely used by patients with DS (AEDs and others) are described. Patients use a large number of pharmaceutical treatments to manage seizures. The five most commonly used AEDs were sodium valproate (66% of the patients; mean daily dose: 660 mg; 24.5 mg per kg bodyweight), bromide (44%; 1462 mg; 51.2 mg per kg), clobazam (41%; 10.4 mg; 0.32 mg per kg), stiripentol (35%; 797 mg; 27.6 mg per kg), and topiramate (24%; 107 mg; 3.5 mg per kg). Ninety percent had reported using emergency medications in the last 3 months;, with the most common medications being Buccolam (40%, an oromucosal form of midazolam) and diazepam (20%, mostly rectal application). No discernable relationships between current medication and age or seizure frequency were observed.

SIGNIFICANCE

This is the first comprehensive report of routine AEDs and emergency medication use in a large sample of patients with DS in Germany over a period of 3-6 months and shows that despite the most common AED combinations being in line with clinical guidelines/best practice, there is no discernable impact of best treatment on seizure frequency. We find a higher use of bromide in Germany compared with other real-world evidence in Europe.

Analysis of the caregiver burden associated with Sanfilippo syndrome type B: panel recommendations based on qualitative and quantitative data

BACKGROUND

Sanfilippo syndrome type B (Sanfilippo B) belongs to a group of rare lysosomal storage diseases characterized by progressive cognitive decline from an early age, acute hyperactivity, and concomitant somatic symptoms. Caregivers face a unique set of challenges related to the complex nature of Sanfilippo B, but the burden and impact on quality of life (QoL) of caregivers is poorly defined and best practice guidance for clinicians is lacking.

METHODS

An international clinical advisors meeting was convened to discuss key aspects of caregiver burden associated with Sanfilippo B based on findings from qualitative and quantitative research undertaken to identify and quantify the nature and impact of the disease on patients and caregivers.

RESULTS

Providing care for patients with Sanfilippo B impinges on all aspects of family life, evolving as the patient ages and the disease progresses. Important factors contributing toward caregiver burden include sleep disturbances, impulsive and hyperactive behavior, and communication difficulties. Caregiver burden remained high throughout the life of the patient and, coupled with the physical burden of daily care, had a cumulative impact that generated significant psychological stress.

CONCLUSION

A Sanfilippo-specific QoL questionnaire is needed that is directed at caregiver needs and burden and best practice management of these domains.

A multicenter, matched case-control analysis comparing burden-of-illness in Dravet syndrome to refractory epilepsy and seizure remission in patients and caregivers in Germany

OBJECTIVE

To compare direct and indirect costs and quality of life (QoL) of pediatric and adult patients with Dravet syndrome (DS), with drug-resistant epilepsy (DRE) and in seizure remission (SR), and their caregivers, in Germany.

METHODS

Questionnaire responses from 93 DS patients and their caregivers were matched by age and gender with responses from 93 DRE and 93 SR patients collected in independent studies, and were compared across main components of QoL, direct costs (patient visits, medication use, care level, medical equipment, and ancillary treatments), and indirect costs (quitting job, reduced working hours, missed days).

RESULTS

Mean total direct costs were highest for DS patients (€4864 [median €3564] vs €3049 [median €1506] for DRE [excluding outliers], P = 0.01; and €1007 [median €311], P < 0.001 for SR). Total lost productivity over 3 months was highest among caregivers of pediatric DS (€4757, median €2841), compared with those of DRE (€1541, P < 0.001; median €0) and SR patients (€891, P < 0.001; median €0). The proportions of caregivers in employment were similar across groups (62% DS, 63% DRE, and 63% SR) but DS caregivers were more likely to experience changes to their working situation, such as quitting their job (40% DS vs 16% DRE and 9% SR, P < 0.001 in both comparisons). KINDL scores were significantly lower for DS patients (62 vs 74 and 72, P < 0.001 in both comparisons), and lower than for the average German population (77). Pediatric caregiver EQ-5D scores across all cohorts were comparable with population norms, but more DS caregivers experienced moderate to severe depressive symptoms (24% vs 11% and 5%). Mean Beck Depression Inventory (BDI-II) score was significantly higher in DS caregivers than either of the other groups (P < 0.001).

SIGNIFICANCE

This first comparative study of Dravet syndrome to difficult-to-treat epilepsy and to epilepsy patients in seizure remission emphasizes the excess burden of DS in components of QoL and direct costs. The caregivers of DS patients have a greater impairment of their working lives (indirect costs) and increased depression symptoms.