9 results on '"West, Michael L."'
Search Results
2. Independent Registries Are Cost-Effective Tools to Provide Mandatory Postauthorization Surveillance for Orphan Medicinal Products.
- Author
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Sirrs SM, Arthus MF, Bichet DG, Rockman-Greenberg C, LeMoine K, Morel CF, Lachmann R, Lynd LD, Wasim S, West ML, and Hollak C
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- Canada, Cost-Benefit Analysis, Data Collection economics, Enzyme Replacement Therapy methods, Fabry Disease drug therapy, Humans, Data Collection methods, Orphan Drug Production statistics & numerical data, Product Surveillance, Postmarketing methods, Registries
- Abstract
Objectives: Orphan medicinal products (OMPs) often receive market authorization under conditions imposed by regulators for ongoing postauthorization surveillance (PAS) to answer questions that remain at the time of market entry. This surveillance may be provided through industry-funded registries (IFRs). Nevertheless, data in these registries may not be of sufficient quality to answer these questions and may not always be accessible for regulatory review. We propose that a mandatory independent registry is an efficient and cost-effective tool for PAS for OMPs., Methods: Using data from the Canadian Fabry Disease Initiative, we reviewed costs per unique patient from sites participating in both the independent national registry and IFRs for Fabry disease and compared data completeness from the Canadian Fabry Disease Initiative to that in published documents from IFRs., Results: The costs of data collection through the independent registry were 17% to 36% (depending on site) lower than costs to collect data in the IFRs, and completeness of data collected through the independent registry was higher than that through the IFRs. Data from the independent registry were reviewed annually to guide indications for publicly funded Fabry disease therapy. Even when enrollment ceased to be a requirement to receive therapy, 77% of patients continued to enroll in the registry, suggesting the structure was acceptable to patients., Conclusions: Independent registries are cost-effective and efficient tools and should be mandated by regulatory agencies as the preferred tool for PAS for OMPs. Countries with publicly funded health systems should consider investment in registry infrastructure for OMPs., (Copyright © 2020 ISPOR–The Professional Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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3. Screening, diagnosis, and management of patients with Fabry disease: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) Controversies Conference.
- Author
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Schiffmann R, Hughes DA, Linthorst GE, Ortiz A, Svarstad E, Warnock DG, West ML, and Wanner C
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- Biomedical Research, Disease Progression, Enzyme Replacement Therapy, Genetic Predisposition to Disease, Genetic Testing, Heredity, Humans, Mutation, Pedigree, Phenotype, Predictive Value of Tests, Prognosis, Risk Assessment, Risk Factors, alpha-Galactosidase genetics, alpha-Galactosidase therapeutic use, Fabry Disease diagnosis, Fabry Disease epidemiology, Fabry Disease genetics, Fabry Disease therapy, Nephrology
- Abstract
Patients with Fabry disease (FD) are at a high risk for developing chronic kidney disease and cardiovascular disease. The availability of specific but costly therapy has elevated the profile of this rare condition. This KDIGO conference addressed controversial areas in the diagnosis, screening, and management of FD, and included enzyme replacement therapy and nonspecific standard-of-care therapy for the various manifestations of FD. Despite marked advances in patient care and improved overall outlook, there is a need to better understand the pathogenesis of this glycosphingolipidosis and to determine the appropriate age to initiate therapy in all types of patients. The need to develop more effective specific therapies was also emphasized., (Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
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4. Urinary biomarker investigation in children with Fabry disease using tandem mass spectrometry.
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Auray-Blais C, Blais CM, Ramaswami U, Boutin M, Germain DP, Dyack S, Bodamer O, Pintos-Morell G, Clarke JT, Bichet DG, Warnock DG, Echevarria L, West ML, and Lavoie P
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- Adolescent, Adult, Aged, Case-Control Studies, Child, Child, Preschool, Chromatography, High Pressure Liquid, Cohort Studies, Fabry Disease genetics, Female, Genotype, Humans, Infant, Male, Middle Aged, Mutation genetics, Young Adult, alpha-Galactosidase genetics, Biomarkers urine, Fabry Disease diagnosis, Fabry Disease urine, Glycolipids urine, Sphingolipids urine, Tandem Mass Spectrometry methods, Trihexosylceramides urine
- Abstract
Background: Fabry disease is an X-linked lysosomal storage disorder affecting both males and females with tremendous genotypic/phenotypic variability. Concentrations of globotriaosylceramide (Gb3), globotriaosylsphingosine (lyso-Gb3)/related analogues were investigated in pediatric and adult Fabry cohorts. The aims of this study were to transfer and validate an HPLC-MS/MS methodology on a UPLC-MS/MS new generation platform, using an HPLC column, for urine analysis of treated and untreated pediatric and adult Fabry patients, to establish correlations between the excretion of Fabry biomarkers with gender, treatment, types of mutations, and to evaluate the biomarker reliability for early detection of pediatric Fabry patients., Method: A UPLC-MS/MS was used for biomarker analysis., Results: Reference values are presented for all biomarkers. Results show that gender strongly influences the excretion of each biomarker in the pediatric Fabry cohort, with females having lower urinary levels of all biomarkers. Urinary distribution of lyso-Gb3/related analogues in treated Fabry males was similar to the untreated and treated Fabry female groups in both children and adult cohorts. Children with the late-onset p.N215S mutation had normal urinary levels of Gb3, and lyso-Gb3 but abnormal levels of related analogues., Conclusions: In this study, Fabry males and most Fabry females would have been diagnosed using the urinary lyso-Gb3/related analogue profile., (Copyright © 2014 Elsevier B.V. All rights reserved.)
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- 2015
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5. How well does urinary lyso-Gb3 function as a biomarker in Fabry disease?
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Auray-Blais C, Ntwari A, Clarke JT, Warnock DG, Oliveira JP, Young SP, Millington DS, Bichet DG, Sirrs S, West ML, Casey R, Hwu WL, Keutzer JM, Zhang XK, and Gagnon R
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- Adolescent, Adult, Aged, Biomarkers urine, Case-Control Studies, Child, Child, Preschool, Creatine urine, Fabry Disease enzymology, Fabry Disease physiopathology, Female, Glycolipids pharmacology, Humans, Kidney physiopathology, Male, Middle Aged, Psychosine analogs & derivatives, Psychosine urine, Reference Standards, Reproducibility of Results, Sex Factors, Sphingolipids pharmacology, Urinalysis standards, Young Adult, alpha-Galactosidase antagonists & inhibitors, Fabry Disease urine, Glycolipids urine, Sphingolipids urine, Urinalysis methods
- Abstract
Background: Fabry disease is characterized by accumulation of glycosphingolipids, such as globotriaosylceramide (Gb(3)), in many tissues and body fluids. A novel plasma biomarker, globotriaosylsphingosine (lyso-Gb(3)), is increased in patients with the disease. Until now, lyso-Gb(3) was not detectable in urine, possibly because of the presence of interfering compounds., Methods: We undertook to: 1) characterize lyso-Gb(3) in urine; 2) develop a method to quantitate urinary lyso-Gb(3) by mass spectrometry; 3) evaluate urinary lyso-Gb(3) as a potential biomarker for Fabry disease; and 4) determine whether lyso-Gb(3) is an inhibitor of α-galactosidase A activity. We analyzed urinary lyso-Gb(3) from 83 Fabry patients and 77 healthy age-matched controls., Results: The intraday and interday bias and precision of the method were <15%. Increases in lyso-Gb(3)/creatinine correlated with the concentrations of Gb(3) (r(2)=0.43), type of mutations (p=0.0006), gender (p<0.0001) and enzyme replacement therapy status (p=0.0012). Urine from healthy controls contained no detectable lyso-Gb(3). Lyso-Gb(3) did not inhibit GLA activity in dried blood spots. Increased urinary excretion of lyso-Gb(3) of Fabry patients correlated well with a number of indicators of disease severity., Conclusion: Lyso-Gb(3) is a reliable independent biomarker for clinically important characteristics of Fabry disease., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
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6. Effects of enzyme replacement therapy in Fabry disease--a comprehensive review of the medical literature.
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Lidove O, West ML, Pintos-Morell G, Reisin R, Nicholls K, Figuera LE, Parini R, Carvalho LR, Kampmann C, Pastores GM, and Mehta A
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- Adult, Child, Fabry Disease complications, Fabry Disease physiopathology, Female, Gastrointestinal Diseases etiology, Gastrointestinal Diseases physiopathology, Humans, Immunoglobulin G immunology, Isoenzymes immunology, Kidney physiopathology, Male, Middle Aged, Nervous System Diseases physiopathology, Quality of Life, Randomized Controlled Trials as Topic, Recombinant Proteins, Treatment Outcome, alpha-Galactosidase immunology, Enzyme Replacement Therapy, Fabry Disease drug therapy, Isoenzymes therapeutic use, Nervous System Diseases etiology, alpha-Galactosidase therapeutic use
- Abstract
Enzyme replacement therapy with α-galactosidase A has been used to treat Fabry disease since 2001. This article reviews the published evidence for clinical efficacy of the two available enzyme preparations. We focused on heart, kidney, and nervous system manifestations, which impact both quality of life and overall prognosis. A literature search was undertaken to identify prospective open or randomized controlled trials of enzyme replacement therapy in patients with Fabry disease published since 2001. To date, no definitive conclusion can be drawn from studies that have directly compared therapeutic responses between the two commercially available enzyme preparations. Significant clinical benefits of enzyme replacement therapy have been demonstrated, mainly in patients at an early phase of the disease, with beneficial effects on heart, kidneys, pain, and quality of life in treated patients. Incidence of antibodies against agalsidase alfa and agalsidase beta observed during major clinical studies suggests a greater antigenic response to agalsidase beta. Further studies are required to confirm the long-term clinical benefits of enzyme replacement therapy. More studies with female patients are needed as are investigations of early initiation of enzyme replacement therapy to determine the optimal time to start treatment to prevent irreversible organ damage. The value of adjunctive and supportive therapies should also be rigorously analyzed.
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- 2010
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7. Therapeutic goals in the treatment of Fabry disease.
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Mehta A, West ML, Pintos-Morell G, Reisin R, Nicholls K, Figuera LE, Parini R, Carvalho LR, Kampmann C, Pastores GM, and Lidove O
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- Cardiovascular Diseases drug therapy, Cardiovascular Diseases etiology, Clinical Trials as Topic, Fabry Disease physiopathology, Female, Gastrointestinal Diseases drug therapy, Gastrointestinal Diseases etiology, Hearing Loss drug therapy, Hearing Loss etiology, Humans, Kidney Diseases drug therapy, Kidney Diseases etiology, Male, Neuralgia drug therapy, Neuralgia etiology, Quality of Life, Enzyme Replacement Therapy, Fabry Disease complications, Fabry Disease drug therapy
- Abstract
Purpose: Fabry disease is a progressive multiorgan, multisystem disorder that is caused by a deficiency in the lysosomal enzyme α-galactosidase A. Serious renal, cardiac, and cerebrovascular involvement are responsible for much of the morbidity and premature mortality associated with Fabry disease, and neuropathic pain, gastrointestinal problems, and hypohidrosis negatively affect quality of life of patients with Fabry disease. Fabry disease is X-linked, but women are often symptomatic and may be as severely affected as men., Methods: We propose a series of therapeutic and symptomatic goals for use in setting the expectations of enzyme replacement therapy and for assessing the response to enzyme replacement therapy in the treatment of Fabry disease., Results: Enzyme replacement therapy has been available since 2001 and has been associated with benefit in clinical trials, including stabilization of kidney function, improvement of cardiac structure and function, reduction in severity of neuropathic pain, and improvement in gastrointestinal involvement., Conclusions: The presentation of these therapeutic goals will aid in the evaluation of response to enzyme replacement therapy and be useful in establishing an overall management plan for individual patients.
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- 2010
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8. The pharmacology of multiple regimens of agalsidase alfa enzyme replacement therapy for Fabry disease.
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Clarke JT, West ML, Bultas J, and Schiffmann R
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- Adolescent, Adult, Clinical Protocols, Dose-Response Relationship, Drug, Drug Administration Schedule, Fabry Disease enzymology, Humans, Infusions, Intravenous, Isoenzymes administration & dosage, Isoenzymes adverse effects, Isoenzymes pharmacokinetics, Isoenzymes pharmacology, Male, Recombinant Proteins, Trihexosylceramides blood, alpha-Galactosidase administration & dosage, alpha-Galactosidase adverse effects, alpha-Galactosidase pharmacokinetics, Fabry Disease therapy, alpha-Galactosidase pharmacology
- Abstract
Purpose: This 10-week study was conducted to determine the pharmacokinetics of varying doses of agalsidase alfa and evaluate the effect of dose and dosing frequency on plasma Gb3 levels., Methods: Eighteen adult male Fabry patients, naive to enzyme replacement therapy, were randomized to one of five regimens: 0.1, 0.2, or 0.4 mg/kg weekly; 0.2 mg/kg every other week (the approved dose); or 0.4 mg/kg every other week. Intravenous infusion rate was 0.1 mg/kg per 20 minutes. Plasma Gb3 levels were assessed at baseline and periodically during the study., Results: The mean half-life was 56-76 minutes, and the mean volume of distribution at steady state was 17%-18% of body weight, with no significant association between dose and half-life, clearance, or volume of distribution at steady state. The area under the curve was linearly proportional to the dose from 0.1 to 0.4 mg/kg. Baseline average plasma Gb3 was 9.12 +/- 2.61 nmol/mL and after 10 weeks of treatment was significantly reduced by about 50% in each group with no statistically significant differences between groups., Conclusions: Reduction of plasma Gb3 levels was independent of dose or dose frequency in the range tested. These observations, coupled with the clinical trial experience of both agalsidase alfa and agalsidase beta, indicate that the standard dose of agalsidase alfa is sufficient to maximally reduce plasma Gb3. However, because plasma Gb3 is not a validated surrogate of disease severity in Fabry disease, further clinical study will be required to determine the optimal dosing regimen for providing maximal clinical benefit.
- Published
- 2007
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9. Patients with Fabry disease on dialysis in the United States.
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Thadhani R, Wolf M, West ML, Tonelli M, Ruthazer R, Pastores GM, and Obrador GT
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- Adult, Age Distribution, Cohort Studies, Female, Humans, Kidney Failure, Chronic therapy, Male, Middle Aged, Prevalence, Survival Analysis, United States epidemiology, X Chromosome, Fabry Disease mortality, Kidney Failure, Chronic mortality, Renal Dialysis statistics & numerical data
- Abstract
Background: : Fabry disease results from an X-linked deficiency of lysosomal alpha-galactosidase A and is a rare cause of end-stage renal disease. Little is known about the characteristics of patients with Fabry disease that initiate dialysis in the United States, although data from Europe suggests these individuals have a poor survival., Methods: : Using the United States Renal Disease System database, we first studied in detail 42 Fabry patients who initiated dialysis between April 1995 (following the introduction of the new detailed HCFA 2728 form) and July 1998. To examine crude survival in a larger cohort, 95 Fabry patients were studied who initiated dialysis between 1985 and 1993, similar to the European Registry. Diabetic and non-diabetic controls matched by age, gender, race, year of dialysis initiation, and initial dialysis modality were examined for comparison., Results: : During the years 1995 to 1998, the mean age of Fabry patients that initiated dialysis was 42 years, 83% were Caucasian, and 10% were African American. Despite the X-linked inheritance of Fabry disease, 12% of Fabry patients on dialysis were female. At initiation of dialysis mean serum albumin and creatinine were significantly higher and mean body mass index was significantly lower among Fabry patients, but mean glomerular filtration rate was similar to controls. Fabry patients tended to have a lower three-year survival compared to non-diabetic controls, but the results were not significantly different. In a larger cohort of Fabry patients who initiated dialysis between 1985 and 1993, the three-year survival of Fabry patients was significantly lower than non-diabetic controls: 63% (95% CI, 50 to 75%) versus 74% (95% CI, 67 to 80%; P=0.03)., Conclusion: : End-stage renal disease is associated with significant morbidity and mortality among patients with Fabry disease. Recent evidence that progression of Fabry disease may be attenuated by enzyme replacement therapy necessitates increased awareness of Fabry disease and its comorbidities.
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- 2002
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