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Journal: Orphanet journal of rare diseases

228

BackgroundCharcot-Marie-Tooth type 1A disease (CMT1A) is a rare orphan inherited neuropathy caused by an autosomal dominant duplication of a gene encoding for the structural myelin protein PMP22, which induces abnormal Schwann cell differentiation and dysmyelination, eventually leading to axonal suffering then loss and muscle wasting. We favour the idea that diseases can be more efficiently treated when targeting multiple disease-relevant pathways. In CMT1A patients, we therefore tested the potential of PXT3003, a low-dose combination of three already approved compounds (baclofen, naltrexone and sorbitol). Our study conceptually builds on preclinical experiments highlighting a pleiotropic mechanism of action that includes downregulation of PMP22. The primary objective was to assess safety and tolerability of PXT3003. The secondary objective aimed at an exploratory analysis of efficacy of PXT3003 in CMT1A, to be used for designing next clinical development stages (Phase 2b/3).Methods80 adult patients with mild-to-moderate CMT1A received in double-blind for 1 year Placebo or one of the three increasing doses of PXT3003 tested, in four equal groups. Safety and tolerability were assessed with the incidence of related adverse events. Efficacy was assessed using the Charcot-Marie-Tooth Neuropathy Score (CMTNS) and the Overall Neuropathy Limitations Scale (ONLS) as main endpoints, as well as various clinical and electrophysiological outcomes.ResultsThis trial confirmed the safety and tolerability of PXT3003. The highest dose (HD) showed consistent evidence of improvement beyond stabilization. CMTNS and ONLS, with a significant improvement of respectively of 8% (0.4% - 16.2%) and 12.1% (2% - 23.2%) in the HD group versus the pool of all other groups, appear to be the most sensitive clinical endpoints to treatment despite their quasi-stability over one year under Placebo. Patients who did not deteriorate over one year were significantly more frequent in the HD group.ConclusionsThese results confirm that PXT3003 deserves further investigation in adults and could greatly benefit CMT1A-diagnosed children, usually less affected than adults.Trial registrationEudraCT Number: 2010-023097-40. ClinicalTrials.gov Identifier: NCT01401257. The Committee for Orphan Medicinal Products issued in February 2014 a positive opinion on the application for orphan designation for PXT3003 (EMA/OD/193/13).

Concepts: Clinical trial, Action potential, Electromyography, Myelin, Vincristine, Charcot-Marie-Tooth disease, Schwann cell, Jean-Martin Charcot

174

Since its enactment in 2000, the European Orphan Medicinal Products Regulation has allowed the review and approval of approaching 70 treatments for some 55 different conditions in Europe. Success does not come without a price, however. Many of these so-called “orphan drugs” have higher price points than treatments for more common diseases. This has been raising debate as to whether the treatments are worth it, which, in turn risks blocking patient access to treatment. To date, orphan drugs have only accounted for a small percentage of the overall drug budget. It would appear that, with increasing numbers of orphan drugs, governments are concerned about the future budget impact and their cost-effectiveness in comparison with other healthcare interventions. Orphan drugs are under the spotlight, something that is likely to continue as the economic crisis in Europe takes hold and governments respond with austerity measures that include cuts to healthcare expenditures. Formally and informally, governments are looking at how they are going to handle orphan drugs in the future. Collaborative proposals between EU governments to better understand the value of orphan drugs are under consideration. In recent years there has been increasing criticism of behaviours in the orphan drug field, mainly centring on two key perceptions of the system: the high prices of orphan drugs and their inability to meet standard cost-effectiveness thresholds; and the construct of the system itself, which allows companies to gain the benefits that accrue from being badged as an orphan drug. The authors hypothesise that, by examining these criticisms individually, one might be able to turn these different “behaviours” into criteria for the creation of a system to evaluate new orphan drugs coming onto the market. It has been acknowledged that standard methodologies for Health Technology Assessments (HTA) will need to be tailored to take into account the specificities of orphan drugs given that the higher price-points claimed by orphan drugs are unlikely to meet current cost-effectiveness thresholds. The authors propose the development of a new assessment system based on several evaluation criteria, which would serve as a tool for Member State governments to evaluate each new orphan drug at the time of pricing and reimbursement. These should include rarity, disease severity, the availability of other alternatives (level of unmet medical need), the level of impact on the condition that the new treatment offers, whether the product can be used in one or more indications, the level of research undertaken by the developer, together with other factors, such as manufacturing complexity and follow-up measures required by regulatory or other authorities. This will allow governments to value an orphan drug that fulfilled all the criteria very differently from one that only met some of them. An individual country could determine the (monetary) value that it places on each of the different criteria, according to societal preferences, the national healthcare system and the resources at its disposal – each individual government deciding on the weighting attributed to each of the criteria in question, based on what each individual society values most. Such a systematic and transparent system will help frame a more structured dialogue between manufacturers and payers, with the involvement of the treating physicians and the patients; and foster a more certain environment to stimulate continued investment in the field. A new approach could also offer pricing and reimbursement decision-makers a tool to handle the different characteristics amongst new orphan drugs, and to redistribute the national budgets in accordance with the outcome of a differentiated assessment. The authors believe that this could, therefore, facilitate the approach for all stakeholders.

Concepts: Health economics, Universal health care, Clinical trial, Price, Rare disease, Orphan drug, European Organization for Rare Diseases, National Organization for Rare Disorders

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BACKGROUND: Families of children living with a rare disease report significant health and social burden, however, few studies have systematically examined family needs by using validated tools to assess the scope and extent of this burden. Our aim was to develop a comprehensive survey to assess health, psychosocial and financial impacts on Australian families caring for a child with a rare disease. METHODS: We developed a self-administered survey for parents/carers incorporating pre-validated tools. The survey included questions about experiences of diagnosis, health services use and needs, needs for peer and financial supports. Forty-seven families attending the state-wide Genetic Metabolic Disorders Service at the Children’s Hospital at Westmead, Sydney were invited to participate. RESULTS: Of 46 families who received the survey, 30 (65%) completed it. Most (93%) found the survey acceptable and relevant (91%). Patients were 1–17 years old, 14 (47%) male, and 12 (40%) non-Caucasian. Eighteen (60%) had a lysosomal storage disease and 12(40%) had a mitochondrial disorder. Eleven (38%) saw 3–5 doctors and four (14%) saw 6–10 doctors before receiving the correct diagnosis; 43% felt diagnosis was delayed. Seven (33%) were dissatisfied with the way diagnosis was given, due to insensitive style of communication, inadequate information and psychological support. Psychosocial impact was moderate to high for 90% of families and the level of impact was not dependent on the level of health functioning of the child. Twenty-six (87%) wanted, but only 13(43%) received, information about peer-support groups. The 30 children accounted for 168 visits to general practitioners and 260 visits to specialist doctors; 21 (70%) children had at least one admission to hospital, including one who had 16 admissions in the previous 12 months. Most families (77%) received financial assistance but 52% believed this was insufficient. Families benefited from a specialised multi-disciplinary clinic but called for patient-held electronic medical records. CONCLUSIONS: Australian families caring for children with genetic metabolic disorders are adversely impacted by delays in diagnosis, lack of easy access to peer support groups and lack of psychological support. Further research is needed to estimate economic impact and to analyse health service delivery models for children with rare diseases in Australia.

Concepts: Health care, Medicine, Health, Epidemiology, Metabolism, Lysosomal storage disease, Physician, Inborn errors of metabolism

171

BACKGROUND: Uveitis is an autoimmune disease of the eye that refers to any of a number of intraocular inflammatory conditions. Because it is a rare disease, uveitis is often overlooked, and the possible associations between uveitis and extra-ocular disease manifestations are not well known. The aim of this study was to characterise uveitis in a large sample of patients and to evaluate the relationship between uveitis and systemic diseases. METHODS: The present study is a cross-sectional study of a cohort of patients with uveitis. Records from consecutive uveitis patients who were seen by the Uveitis Service in the Department of Ophthalmology at the Medical University of Vienna between 1995 and 2009 were selected from the clinical databases. The cases were classified according to the Standardization of Uveitis Nomenclature Study Group criteria for uveitis. RESULTS: Data were available for 2619 patients, of whom 59.9% suffered from anterior, 14.8% from intermediate, 18.3% from posterior and 7.0% from panuveitis. 37.2% of all cases showed an association between uveitis and extra-organ diseases; diseases with primarily arthritic manifestations were seen in 10.1% of all cases, non-infectious systemic diseases (i.e., Behcet’s disease, sarcoidosis or multiple sclerosis) in 8.4% and infectious uveitis in 18.7%. 49.4% of subjects suffering from anterior uveitis tested positively for the HLA-B27 antigen. In posterior uveitis cases 29% were caused by ocular toxoplasmosis and 17.7% by multifocal choroiditis. CONCLUSION: Ophthalmologists, rheumatologists, infectiologists, neurologists and general practitioners should be familiar with the differential diagnosis of uveitis. A better interdisciplinary approach could help in tailoring of the work-up, earlier diagnosis of co-existing diseases and management of uveitis patients.

Concepts: Medicine, Epidemiology, Medical terms, Infection, Rheumatoid arthritis, Ophthalmology, Ankylosing spondylitis, Uveitis

170

BACKGROUND: The clinical course of Cystic Fibrosis (CF) is usually measured using the percent predicted FEV1 and BMI Z-score referenced against a healthy population, since achieving normality is the ultimate goal of CF care. Referencing against age and sex matched CF peers may provide valuable information for patients and for comparison between CF centers or populations. Here, we used a large database of European CF patients to compute CF specific reference equations for FEV1 and BMI, derived CF-specific percentile charts and compared these European data to their nearest international equivalents. METHODS: 34859 FEV1 and 40947 BMI observations were used to compute European CF specific percentiles. Quantile regression was applied to raw measurements as a function of sex, age and height. Results were compared with the North American equivalent for FEV1 and with the WHO 2007 normative values for BMI. RESULTS: FEV1 and BMI percentiles illustrated the large variability between CF patients receiving the best current care. The European CF specific percentiles for FEV1 were significantly different from those in the USA from an earlier era, with higher lung function in Europe. The CF specific percentiles for BMI declined relative to the WHO standard in older children. Lung function and BMI were similar in the two largest contributing European Countries (France and Germany). CONCLUSION: The CF specific percentile approach applied to FEV1 and BMI allows referencing patients with respect to their peers. These data allow peer to peer and population comparisons in CF patients.

Concepts: Median, Quantile, Cystic fibrosis, Peer-to-peer, Quartile, Reference, Percentile rank, File sharing

168

Blistering in epidermolysis bullosa simplex type Dowling-Meara (EBS-DM) is associated with an inflammatory phenotype, which can be disrupted by diacerein in vitro. In this pilot study we hypothesized, that a topical formulation of diacerein 1% reduces blistering. Five patients initially applied diacerein underneath both armpits. Then, each participant received 1% diacerein-cream for one armpit, and placebo for the other (randomized withdrawal). The number of blisters was reduced significantly (left: -78%; right: -66% of baseline) within two weeks and remained significantly below the initial level even during withdrawal in four patients. These findings point to a relevant effect of diacerein and provide important information for a confirmative study.

Concepts: Typography, Typeface, Axilla, Epidermolysis bullosa

168

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder caused by alpha-galactosidase A deficiency leading to renal, cardiac, cerebrovascular disease and premature death. Treatment with alpha-galactosidase A (enzyme replacement therapy, ERT) stabilises disease in some patients, but long term effectiveness is unclear. METHODS: Renal, cardiac, and cerebral outcomes were prospectively studied in males and females with Fabry disease treated with ERT. Additionally, the occurrence of major cardiac events, stroke, end-stage renal disease and death was compared to a natural history (NH) cohort meeting treatment criteria. RESULTS: Of 75 patients on ERT (median treatment duration 5.2 years, range 0.05-11.0), prospective follow-up was available for 57 adult patients (30 males) and 6 adolescents. Renal function declined in males (-3.4 ml/min/1.73 m2 per year, SE 0.2; p < 0.001) despite ERT, but followed the normal course in females (-0.8 ml/min/1.73 m2 per year, SE 0.3; p = 0.001). Cardiac mass increased during ERT in males (+ 1.2 gram/m2.7, SE 0.3; p < 0.001), but remained stable in females (-0.3 gram/m2.7 per year, SE 0.4; p = 0.52). ERT did not prevent the occurrence of cerebral white matter lesions. Comparison of ERT treated to untreated patients revealed that the odds to develop a first complication increased with age (OR 1.05 (95% CI: 1.0-1.1) per year, p = 0.012). For development of a first or second complication the odds declined with longer treatment duration (OR 0.81 (95% CI: 0.68-0.96) per year of ERT, p = 0.015;OR 0.52 (0.31-0.88), p = 0.014 respectively). CONCLUSIONS: Long term ERT does not prevent disease progression, but the risk of developing a first or second complication declines with increasing treatment duration. ERT in advanced Fabry disease seems of doubtful benefit.

Concepts: Renal failure, Chronic kidney disease, Kidney, Nephrology, Death, Lysosomal storage disease, Enzyme replacement therapy, Fabry disease

168

BACKGROUND: Propionic acidemia is an inherited disorder caused by deficiency of propionyl-CoA carboxylase. Although it is one of the most frequent organic acidurias, information on the outcome of affected individuals is still limited.Study design/methods: Clinical and outcome data of 55 patients with propionic acidemia from 16 European metabolic centers were evaluated retrospectively. 35 patients were diagnosed by selective metabolic screening while 20 patients were identified by newborn screening. Endocrine parameters and bone age were assessed. In addition, IQ testing was performed and the patients' and their families' quality of life was assessed. RESULTS: The vast majority of patients (>85%) presented with metabolic decompensation in the neonatal period. Asymptomatic individuals were the exception. About three quarters of the study population was mentally retarded, median IQ was 55. Apart from neurologic symptoms, complications comprised hematologic abnormalities, cardiac diseases, feeding problems and impaired growth. Most patients considered their quality of life high. However, according to the parents' point of view psychic problems were four times more common in propionic acidemia patients than in healthy controls. CONCLUSION: Our data show that the outcome of propionic acidemia is still unfavourable, in spite of improved clinical management. Many patients develop long-term complications affecting different organ systems. Impairment of neurocognitive development is of special concern. Nevertheless, self-assessment of quality of life of the patients and their parents yielded rather positive results.

Concepts: Medicine, Infant, Pediatrics, Intelligence quotient, Mental retardation, Propionyl-CoA carboxylase, Propionic acidemia, Propionyl-CoA

168

BACKGROUND: Pathologic studies played an important role in evaluating patients with Alport syndrome besides genotyping. Difficulties still exist in diagnosing Alport syndrome (AS), and misdiagnosis is a not-so-rare event, even in adult patient evaluated with renal biopsy. METHODS: We used nested case–control study to investigate 52 patients previously misdiagnosed and 52 patients initially diagnosed in the China Alport Syndrome Treatments and Outcomes Registry e-system. RESULTS: We found mesangial proliferative glomerulonephritis (MsPGN, 26.9%) and focal and segmental glomerulosclerosis (FSGS, 19.2%) were the most common misdiagnosis. FSGS was the most frequent misdiagnosis in female X-linked AS (fXLAS) patients (34.8%), and MsPGN in male X-linked AS (mXLAS) patients (41.2%). Previous misdiagnosed mXLAS patients (13/17, 76.5%) and autosomal recessive AS (ARAS) patients (8/12, 66.7%) were corrected after a second renal biopsy. While misdiagnosed fXLAS patients (18/23, 78.3%) were corrected after a family member diagnosed (34.8%) or after rechecking electronic microscopy and/or collagen-IV alpha-chains immunofluresence study (COL-IF) (43.5%) during follow-up. With COL-IF as an additional criterion for AS diagnosis, we found that patients with less than 3 criteria reached have increased risk of misdiagnosis (3.29-fold for all misdiagnosed AS patients and 3.90-fold for fXLAS patients). CONCLUSION: We emphasize timely and careful study of electronic microscopy and COL-IF in pathologic evaluation of AS patients. With renal and/or skin COL-IF as additional criterion, 3 diagnosis criteria reached are the cutoff for diagnosing AS pathologically.

Concepts: Medical terms, Diagnosis, Pathology, Medical diagnosis, Glomerulonephritis, Sex linkage, Dominance, Alport syndrome

152

Factors associated with survival in pemphigus have not yet been thoroughly addressed. Therefore, in the present study, risk factors for overall mortality in a large group of patients with pemphigus vulgaris and foliaceus were investigated.

Concepts: Cohort study, Epidemiology, Actuarial science, Future, Pemphigus, Pemphigus foliaceus, Chronic blistering cutaneous conditions