[Lysosomal Storage Diseases: Challenges in Multiprofessional Patient Care with Enzyme Replacement Therapy]. / Lysosomale Speichererkrankungen: Herausforderungen bei der sektorübergreifenden, multiprofessionellen Patientenversorgung mit Enzymersatztherapie.

Background Due to their rarity studies in (ultra-) rare diseases are difficult. Only for a minority of these diseases causal therapies are available. Development and production of enzyme replacement therapies (ERT) for example are challenging and expensive. The number of patients is low, costs per patient are high. We will focus on the challenges of providing long-term ERT to patients with lysosomal storage diseases (LSD) in an out- and inpatient setting based on a literature search in Pubmed and own experience. Many ERTs for LSDs have a positive cost-benefit ratio. Possible side-effects are severe allergic reactions. ERT is covered by the insurance companies when prescribed by a physician, however they are liable to recourse by the insurance company as the expenses for drugs of the prescribing physician will be above average. In most cases the recourse can be averted if diagnoses of individual patients are disclosed. Intravenous infusion of ERT is not well-regulated in Germany/Austria. Infusion on a ward is safe however often not covered by the insurance companies as patients do not stay overnight. Another option is infusion in a day-care setting, however the lump sum paid for infusion does not cover costs for ERT. On an individual basis, reimbursement for medication (ERT) has to be negotiated with the insurance companies before infusion takes place. Home infusions are feasible, however careful evaluations of the infusion-team and the risk for side-effects have to be performed on an individual basis, legal issues have to be considered. In- and outpatient ERT of patients with LSDs is challenging but feasible after individual evaluation of patient and infusion team.

The effectiveness and cost-effectiveness of enzyme and substrate replacement therapies: a longitudinal cohort study of people with lysosomal storage disorders.

OBJECTIVES: To determine natural history and estimate effectiveness and cost of enzyme replacement therapy (ERT) and substrate replacement therapy (SRT) for patients with Gaucher disease, Fabry disease, mucopolysaccharidosis type I (MPS I), mucopolysaccharidosis type II (MPS II), Pompe disease and Niemann-Pick type C (NPC) disease. DESIGN: Cohort study including prospective and retrospective clinical- and patient-reported data. Age- and gender-adjusted treatment effects were estimated using generalised linear mixed models. Treated patients contributed data before and during treatment. Untreated patients contributed natural history data. SETTING: National Specialised Commissioning Group-designated lysosomal storage disorder (LSD) treatment centres in England. PARTICIPANTS: Consenting adults and children with a diagnosis of Gaucher disease (n = 272), Fabry disease (n = 499), MPS I (n = 126), MPS II (n = 58), NPC (n = 58) or Pompe disease (n = 93) who had attended a treatment centre in England. INTERVENTIONS: ERT and SRT. MAIN OUTCOME MEASURES: Clinical outcomes chosen by clinicians to reflect disease progression for each disorder; patient-reported quality-of-life (QoL) data; cost of treatment and patient-reported service-use data; numbers of hospitalisations, outpatient and general practitioner appointments; medication use; data pertaining to associated family/carer costs and QoL impacts. RESULTS: Seven hundred and eleven adults and children were recruited. In those with Gaucher disease (n = 175) ERT was associated with improved platelet count, haemoglobin, liver function and reduced risk of enlarged liver or spleen. No association was found between ERT and QoL. In patients with Fabry disease (n = 311) increased time on ERT was associated with small decreases in left ventricular mass and improved glomerular filtration rate, but not with changes in risk of stroke/transient ischaemic attacks or the need for a hearing aid. There was a statistically significant association between duration of ERT use and worsening QoL and fatigue scores. We found no statistical difference in estimates of treatment effectiveness between the two preparations, agalsidase beta (Fabrazyme(®), Genzyme) (n = 127) and agalsidase alpha (Replagal(®), Shire HGT) (n = 91), licensed for this condition. In Pompe disease (n = 77) our data provide some evidence of a beneficial effect on muscle strength and mobility as measured by a 6-minute walk test in adult-onset patients; there were insufficient data from infantile-onset Pompe patients to estimate associations between ERT and outcome. Among subjects with MPS I (n = 68), 42 of the 43 patients with MPS I subtype Hurler's disease had undergone a bone marrow transplant. No significant associations were found between ERT and any outcome measure for the MPS I subtype Scheie disease and heparan sulphate patients. An association between duration of ERT and growth in children was the only statistically significant finding among patients with MPS II (n = 39). There were insufficient data for patients with NPC disease to draw any conclusions regarding the effectiveness of SRT. The current annual cost to the NHS of the different ERTs means that between 3.6 and 17.9 discounted quality-adjusted life-years (QALYs) for adult patients and between 2.6 and 10.5 discounted QALYs for child patients would need to be generated for each year of being on treatment for ERTs to be considered cost-effective by conventional criteria. CONCLUSIONS: These data provide further evidence on the effectiveness of ERT in people with LSDs. However, the results need to be interpreted in light of the fact that the data are observational and the relative lack of power due to the small numbers of patients with MPS I, MPS II, Pompe disease and NPC disease. Future work should aim to effectively address the unanswered questions and this will require agreement on a common set of outcome measures and their consistent collection across all treatment centres. FUNDING: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 16, No. 39. See the HTA programme website for further project information.

The path less costly.

When faced with a competitive threat, two companies took diametrically opposite approaches. Both were ultimately successful, but Genzyme's decision proved to be the cleaner and cheaper option.

Expensive drugs for rare disorders: to treat or not to treat? The case of enzyme replacement therapy for mucopolysaccharidosis VI.

BACKGROUND: Mucopolysaccharidosis VI (MPS VI) is a very rare, chronically debilitating lysosomal storage disorder that develops in people with an enzyme deficiency. Clinical characteristics and progression rates vary widely between patients. The recent introduction of enzyme replacement therapy (ERT) has improved considerably the lives of patients with MPS VI, at an annual cost of treatment between euro 150,000 and euro 450,000 per patient. SCOPE: This Commentary article addresses the controversial topic of granting reimbursement for expensive treatment options for orphan diseases, such as MPS VI. The discussion reflects clinical, economic and ethical aspects and incorporates insights from the relevant literature (based on a Medline search to September 2008) on MPS VI, efficacy of ERT, orphan drugs, and the economics and ethics of health-care prioritisation. FINDINGS: Although ERT for MPS VI received marketing authorisation in the European Union in January 2006, patients' access to this therapy varies geographically due to differences between national reimbursement schemes for orphan drugs. Some inclusion and exclusion criteria for treatment of MPS VI patients with ERT appear arbitrary and may contribute to the exclusion from treatment of patients who could benefit in the long term. Reimbursement schemes which rely on proof of short-term treatment effectiveness may discriminate against slowly progressive patients, as health gain can often not be confirmed over a short period of time in these patients. Conventional cost-effectiveness analysis remains silent on crucial issues related to budgetary impact, i.e. opportunity cost from a system perspective, and fair access to treatment. CONCLUSIONS: To prevent patients from being deprived of effective treatment, it is suggested that inclusion and exclusion criteria for treatment should be primarily based on a careful individual assessment of expected long-term clinical benefits. Once treatment has been agreed to as the correct option on clinical grounds, it is further argued that the conventional cost-effectiveness criterion currently in widespread use does not offer a sufficient basis for rejecting reimbursement of expensive treatments for exceptionally rare disorders, providing that decisions on reimbursement are intended to reflect public preferences.

Enzyme reconstitution/replacement therapy for lysosomal storage diseases.

PURPOSE OF REVIEW: Over the past 15 years, the lysosomal storage diseases have become paradigms for the specific treatment of monogenic disorders, particularly those affecting children. This review summarizes the phenotypes and recent literature regarding enzyme reconstitution (replacement) therapy and outcomes for such treatable lysosomal storage diseases: Gaucher disease, Fabry disease, Pompe disease and the mucopolysaccharidoses. RECENT FINDINGS: Recent clinical trials have shown that enzyme reconstitution therapy effectively treats many of the manifestations of the lysosomal storage diseases. When initiated early in the disease course, enzyme reconstitution therapy can reverse some disease manifestations, but may not completely alleviate the disease progression. Enzyme reconstitution therapy is generally well tolerated. Many adverse events are antibody-related, but can be managed without requiring cessation of enzyme reconstitution therapy. Documented IgE reactions, i.e. anaphylactoid, are quite rare (fewer than 1%). SUMMARY: Enzyme reconstitution therapy is a safe and effective treatment modality available for several of the lysosomal storage diseases. Owing to the short history of enzyme reconstitution therapy, the long-term outcomes of enzyme reconstitution therapy-treated individuals are unknown and require further investigation. Medical professionals must learn to identify patients likely to benefit from these life-changing therapies so as to prevent many of the devastating, irreversible complications of the lysosomal storage diseases.

Lysosomal storage diseases: natural history and ethical and economic aspects.

Potential treatment for lysosomal diseases now includes enzyme replacement therapy, substrate reduction therapy, and chaperone therapy. The first two of these have been implemented commercially, and the spectrum of diseases that are now treatable has expanded from Gaucher disease to include several other disorders. Treatment of these diseases is extremely costly. We explore some of the reasons for the high cost and discuss how, by proper selection of patients and appropriate dosing, the economic burden on society of treating these disease may be ameliorated, at least in part. However, the cost of treating rare diseases is a growing problem that society needs to address.

Prevalence of lysosomal storage disorders.

CONTEXT: Lysosomal storage disorders represent a group of at least 41 genetically distinct, biochemically related, inherited diseases. Individually, these disorders are considered rare, although high prevalence values have been reported in some populations. These disorders are devastating for individuals and their families and result in considerable use of resources from health care systems; however, the magnitude of the problem is not well defined. To date, no comprehensive study has been performed on the prevalence of these disorders as a group. OBJECTIVE: To determine the prevalence of lysosomal storage disorders individually and as a group in the Australian population. DESIGN: Retrospective case studies. SETTING: Australia, from January 1, 1980, through December 31, 1996. MAIN OUTCOME MEASURE: Enzymatic diagnosis of a lysosomal storage disorder. RESULTS: Twenty-seven different lysosomal storage disorders were diagnosed in 545 individuals. The prevalence ranged from 1 per 57000 live births for Gaucher disease to 1 per 4.2 million live births for sialidosis. Eighteen of 27 disorders had more than 10 diagnosed cases. As a group of disorders, the combined prevalence was 1 per 7700 live births. There was no significant increase in the rate of either clinical diagnoses or prenatal diagnoses of lysosomal storage disorders during the study period. CONCLUSIONS: Individually, lysosomal storage disorders are rare genetic diseases. However, as a group, they are relatively common and represent an important health problem in Australia.

Electron microscopic examination of skin biopsy as a cost-effective tool in the diagnosis of lysosomal storage diseases.

In this report, we have summarized our 9-year experience of over 100 proven cases of lysosomal storage disease using electron microscopic evaluation of skin biopsies as a screening tool. The skin biopsy was very specific in establishing the diagnosis in only two disorders, namely neuronal ceroid lipofuscinosis and mucolipidosis IV. Although the biopsy was not diagnostic in other categories of storage diseases, it proved to be highly sensitive and provided valuable clues to direct further investigations on the basis of morphologic appearance of stored material and the cell type affected. Only in two cases of biochemically proven lysosomal storage disease was the morphologic diagnosis unable to be confirmed. We have compared the cost of screening for storage disorders using skin biopsy with the cost of performing multiple lysosomal enzyme assays. Our findings indicate that the skin biopsy, although more expensive than a single enzyme assay, provides an efficient, rapid, cost-effective tool to screen for more than 35 lysosomal storage disorders.