Advent Of Enzyme Replacement Therapy Research Articles

Management of Craniosynostosis in Lethal Perinatal Hypophosphatasia.

Although perinatal lethal hypophosphatasia (HPP) was once a disease with a universally poor prognosis, it has now become a rare but treatable condition with the advent of enzyme replacement therapy with asfotase alfa. As a result, a greater population of patients with perinatal HPP are presenting with abnormal head shape and craniosynostosis. The authors present here 3 cases of perinatal lethal HPP, 1 treated with traditional open cranial vault remodeling and 2 treated utilizing distraction osteogenesis techniques. All patients demonstrated outcomes comparable to those previously reported with traditional observation or open cranial vault repair. Thorough consideration and discussion between the surgical team and patient's family is needed to determine a treatment plan that best addresses the goals of patient and family in light of recent advances in medical treatment in this rare patient population in which surgical interventions were previously nearly impossible. This article further supports the safety and efficacy of surgical intervention and explores the utility of distraction osteogenesis to address craniosynostosis in this patient population.

Fabry disease in the practice of a neurologist

Fabry disease (FD) is a rare lysosomal storage disease caused by mutations in the GLA gene that results in deficient α-galactosidase A (α-Gal A) activity and is inherited in an X-linked manner. A decrease or complete absence of the activity of the a-Gal A enzyme causes a progressive accumulation of glycosphingolipids in the cells of the body. Due to progression of the disease, there is a rapid damage to the internal organs (especially kidneys and heart) and the brain, that is a common cause of premature death in a person with FD. The earliest possible detection of FD and timely treatment is the key to reducing the risk of severe and lifethreatening complications. Worldwide, the gold standard of care for patients with FD is enzyme replacement therapy (ERT) in combination with symptomatic therapy. One of ERT remedy for FD is beta-agalsidase (Fabrazyme®). Fabrazyme® is produced by Sanofi and approved in many countries around the world. With the advent of ERT, the quality of life of patients with FD has significantly improved and the frequency of premature death among these patients has decreased.

Effect of long term enzyme replacement therapy in late onset Pompe disease: A single-centre experience

Late onset Pompe disease (LOPD) is a slowly progressive metabolic myopathy with variable clinical severity. The advent of enzyme replacement therapy (ERT) has modified the natural course of the disease, though the treatment effect on adult patients is modest compared to infants with the classic form. This study aims to describe the long-term clinical outcome of the Greek LOPD cohort, as assessed by 6 min walk test, muscle strength using MRC grading scale and spirometry. ERT efficacy was estimated using statistical methodology that is novel in the context of Pompe disease, which at the same time is well-suited to longitudinal studies with small samples and missing data (local non-linear regression analysis). Improvement over baseline was significant at 1 year for motor performance and muscle strength (p < 0.05), and at 2 years for FVC-U and FVC-S (p < 0.05). A subgroup analysis showed that the onset of the disease before adulthood (18 years), a male gender, and a latency of more than 2 years between the onset of symptoms and ERT administration are unfavorable prognostic factors. Conclusively, this study presents longitudinal data from the Greek LOPD cohort supporting previous observations, that therapeutic delay is related to worse prognosis and treatment effects may decline after several years of ERT.

Novel Enzyme Replacement Therapies for Neuropathic Mucopolysaccharidoses.

Although the advent of enzyme replacement therapy (ERT) for mucopolysaccharidoses (MPS) has paved the way for the treatment for these hereditary disorders, the blood brain barrier (BBB) has prevented patients with MPS involving the central nervous system (CNS) from benefitting from ERT. Therefore, finding ways to increase drug delivery into the brain across the BBB remains a crucial challenge for researchers and clinicians in the field. Attempts have been made to boost brain uptake of enzymes by targeting various receptors (e.g., insulin and transferrin), and several other administration routes have also been tested. This review summarizes the available information on clinical trials (completed, ongoing, and planned) of novel therapeutic agents with efficacy against CNS symptoms in neuropathic MPS and also discusses the common associated challenges and pitfalls, some of which may help elucidate the pathogenesis of the neurodegeneration leading to the manifold CNS symptoms. A summary of current knowledge pertaining to the neuropathological progression and resultant neuropsychiatric manifestations is also provided, because it should be useful to ERT researchers looking for better approaches to treating CNS lesions in MPS.

SAT-102 AUTOLOGOUS STEM CELL THERAPY USING LENTIVIRAL VECTOR FOR TREATMENT OF FABRY DISEASE

Fabry disease (FD) is an X-linked lysosomal storage disease cause by deficiency of the enzyme alpha-galactosidase A (AGAL). This results in widespread multi-organ damage subsequent to the accumulation of globotriaosylsphingosine. The outlook of FD has significantly improved with the advent of enzyme replacement therapy (ERT) and oral chaperone therapy. These have stabilised renal and cardiac function and reduced symptom burden. These lifelong therapies do not prevent cerebrovascular complications.

The impact of Pompe disease on smooth muscle: a review.

Pompe disease (OMIM 232300) is an autosomal recessive disorder caused by mutations in the gene encoding acid α-glucosidase (GAA) (EC 3.2.1.20), the enzyme responsible for hydrolyzing lysosomal glycogen. The primary cellular pathology is lysosomal glycogen accumulation in cardiac muscle, skeletal muscle, and motor neurons, which ultimately results in cardiorespiratory failure. However, the severity of pathology and its impact on clinical outcomes are poorly described in smooth muscle. The advent of enzyme replacement therapy (ERT) in 2006 has improved clinical outcomes in infantile-onset Pompe disease patients. Although ERT increases patient life expectancy and ventilator free survival, it is not entirely curative. Persistent motor neuron pathology and weakness of respiratory muscles, including airway smooth muscles, contribute to the need for mechanical ventilation by some patients on ERT. Some patients on ERT continue to experience life-threatening pathology to vascular smooth muscle, such as aneurysms or dissections within the aorta and cerebral arteries. Better characterization of the disease impact on smooth muscle will inform treatment development and help anticipate later complications. This review summarizes the published knowledge of smooth muscle pathology associated with Pompe disease in animal models and in patients.

The emerging phenotype of late-onset Pompe disease: A systematic literature review.

Pompe disease is an autosomal recessive disorder caused by deficiency of the lysosomal glycogen-hydrolyzing enzyme acid α-glucosidase (GAA). The adult-onset form, late-onset Pompe disease (LOPD), has been characterized by glycogen accumulation primarily in skeletal, cardiac, and smooth muscles, causing weakness of the proximal limb girdle and respiratory muscles. However, increased scientific study of LOPD continues to enhance understanding of an evolving phenotype. To expand our understanding of the evolving phenotype of LOPD since the approval of enzyme replacement therapy (ERT) with alglucosidase alfa (Myozyme™/Lumizyme™) in 2006. All articles were included in the review that provided data on the charactertistics of LOPD identified via the PubMed database published since the approval of ERT in 2006. All signs and symptoms of the disease that were reported in the literature were identified and included in the review. We provide a comprehensive review of the evolving phenotype of LOPD. Our findings support and extend the knowledge of the multisystemic nature of the disease. With the advent of ERT and the concurrent increase in the scientific study of LOPD, the condition once primarily conceptualized as a limb-girdle muscle disease with prominent respiratory involvement is increasingly recognized to be a condition that results in signs and symptoms across body systems and structures.

DOENÇA DE GAUCHER TIPO 1 NO ESQUELETO: REVISÃO DA AMÉRICA LATINA

RESUMO A doença de Gaucher (DG) é a doença de depósito lisossômico mais prevalente, que se caracteriza pelo acúmulo de glicosilceramida e glucosilesfingosina em todos os tecidos do corpo. Com o advento da terapia de reposição de enzimas, o prognóstico dos pacientes com DG melhorou acentuadamente. Ainda assim, as manifestações esqueléticas associadas à DG respondem lentamente à terapia de reposição de enzimas e são as que contribuem de forma mais significativa para a morbidade do paciente. Esta revisão das manifestações ósseas da DG apresenta as mais recentes teorias sobre a sua fisiopatologia e uma revisão sistemática de estudos com pacientes latino-americanos que relataram a frequência das manifestações ósseas e os efeitos da terapia de reposição de enzimas sobre seu tratamento. Concluímos, destacando a importância da identificação precoce e do manejo adequado das doses apropriadas da terapia de reposição de enzimas para reduzir a morbidade causada pela DG.

Small Molecules

Lysosomal storage disorders are rare genetic disorders due to deficient lysosomal activity, which leads to progressive accumulation of nonmetabolized substrates. Patient’s clinical outcomes have significantly improved since the advent of enzyme replacement therapy, even though this therapeutic approach presents important limitations, such as immune reactions, low bioavailability of recombinant enzymes, and incapability to reach the central nervous system. New strategies based on gene therapy or small molecules have been proposed and tested as an alternative to enzyme replacement therapy or to complement it. Small molecules are orally administrated, no antigenic compound that can diffuse across cell membranes and distribute in steady-state concentrations, also reaching the central nervous system. Substrate reduction therapy, pharmacological chaperones, and stop-codon read-through enhancers are small molecules currently available for the treatment of lysosomal storage disorders. This article describes the characteristics of this class of compounds and the possible strategies to improve their efficiency in future development.

Neuronopathic Gaucher Disease

Gaucher disease (GD) has been classically divided into three phenotypes primarily according to the absence (type 1 GD or nonneuronopathic GD) or presence and severity (types 2 and 3 GD or neuronopathic GD) of neurological involvement. Despite such distinction, neurological manifestations have been recorded also in patients with type 1 GD: in this latter form, however, such manifestations are different and, in the majority of cases, of much less severity than those associated with types 2 and 3 GD. Significant advances in therapy have been achieved, primarily after the advent of enzyme replacement therapy (ERT). As it occurs in patients with type 1 GD, ERT is able to reverse systemic and extraneurological manifestations of type 3 GD, although evidence suggests that ERT is not able to prevent the progression of neurological involvement in the long term. Thus, it is necessary to better understand the pathophysiological mechanism underlying neurological involvement in GD patients, allowing the development of new therapeutic approaches capable of improving central nervous system manifestations in GD.

Persistent immune alterations and comorbidities in splenectomized patients with Gaucher disease

Gaucher disease (GD) is an autosomal recessive disorder caused by mutations in the gene encoding acid-β-glucosidase, resulting in functional disruptions in degradation of glycosphingolipids and lysosomal accumulation of the substrates. The most frequent clinical presentations of GD are thrombocytopenia, splenomegaly and bone pain. Prior to advent of enzyme replacement therapy, splenectomy was performed for complications of hypersplenism such as severe thrombocytopenia and transfusion dependency. Though there is evidence about worsening bone disease after splenectomy, there is no systematic study to assess its effects on the immune system in GD patients. In order to investigate the long-term immunological effects of splenectomy, we used flow cytometry to compare the immunophenotypes of GD patients who had undergone splenectomy (SGD) to those with intact spleen. The results show that SGD patients have significantly fewer CD27+/IgM+ B-cells but more CD4+/CD45RO+ and CD8+/CD45RO+ T-cells. The most surprising finding was an almost complete absence of circulating dendritic cells in SGD patients. In addition, splenectomized subjects had comorbidities, the most common being monoclonal gammopathy of undetermined significance (MGUS). Taken together, these results highlight the persistence of multiple immune alterations and comorbidities coexisting in higher frequency in the SGD group and they are not affected by GD specific therapy.

Longitudinal polysomnographic findings in infantile Pompe disease.

Infantile Pompe disease is a rare, metabolic disorder due to deficiency of the enzyme acid α-glucosidase that degrades lysosomal glycogen. The deficiency leads to multisystem dysfunction. Neuromuscular weakness due to metabolic myopathy is present, which predisposes children to sleep-disordered breathing. With the advent of enzyme replacement therapy (ERT), children are living longer, and there is a new natural history that is emerging. In a prior paper on our cohort of infantile Pompe disease patients, we reported a high incidence of both hypoventilation and obstructive sleep apnea (OSA). In this retrospective study, we analyzed longitudinal nocturnal polysomnography results from 10 patients with infantile-onset Pompe disease, all of which were on enzyme replacement therapy for a mean of 34.9 months at the time of follow-up study. Patients demonstrated relative stability in sleep disordered breathing, with a trend towards improvement in both OSA and central sleep apnea. ERT may help in the treatment of sleep apnea in this cohort.

PO-0043 Classic Infantile-onset Pompe Disease: A Study Of 8 Cases

Introduction Classic infantile pompe disease is an autosomal recessive inherited disorder caused by a deficiency of alpha 1–4 glucosidase, resulting in accumulation of glycogen in skeletal muscle and heart. It’s characterised by hypotonia, cardiomegaly and hypertrophic cardiomyopathy, feeding difficulties and respiratory distress, all patients died in the first year of life. Patients and methods A retrospective study of cases of classic infantile pompe disease collected in the Department of Paediatrics, Hospital Hedi Chaker, Sfax over a period of 7 years (2008–2013). Results During the study period we collected 8 cases of the disease. The average age at diagnosis was 3 months and 6 days. All patients were eutrophic. Hypotonia was noted in all cases, Respiratory distress in seven cases, cyanosis in 4 cases and a systolic murmur in 5 cases. Hepatomegaly was constant, macroglossia was noted in one patient. Chest radiography showed cardiomegaly in all cases. Electrocardiogram, showed electrical signs of left ventricular hypertrophy, wide QRS complex, a shortening of the PR interval was seen in 4 cases. Echocardiography confirmed diagnosis of hypertrophic cardiomyopathy. The dosage of acid maltase activity practiced in 5 patients, showed no enzyme activity. The genetic study of 4 patients showed a mutation in the homozygous state of the GAA gene. Treatment was purely symptomatic involving propranolol, oxygen and antibiotics. All patients died. Conclusion The fatal evolution of the classic infantile form of Pompe disease is being changed by the advent of enzyme replacement therapy wich significantly increased the survival of these patients.

Treatment of Lysosomal Storage Diseases: Recent Patents and Future Strategies

Lysosomal storage diseases (LSDs) are a group of rare genetic multisystemic disorders, resulting in deficient lysosomal activity. These pathologies are characterized by progressive accumulation of storage material within the lysosomes, ultimately leading to organ dysfunctions. LSDs patient's clinical outcomes have significantly improved, since the advent of enzyme replacement therapy (ERT). ERT is approved worldwide for 6 LSDs: Gaucher disease, Fabry disease, Mucopolysaccharidosis types I, II, and VI, and Pompe disease. The efficacy and safety of ERT for LSDs has been confirmed by extensive clinical trials, however therapy with infused protein is life-long and disease progression is still observed in treated patients. Obstacles to successful ERT, such as immune reactions against the infused enzyme, miss-targeting of recombinant enzymes, and difficult delivery to crucial tissues (i.e. brain and bone), determine the need for further research, in order to ameliorate therapeutic strategies. Viral gene therapy, stem cell based therapy, pharmacological chaperones and could be considered essential tools for future improvement of recombinant enzyme trafficking and targeting. This review will discuss recent patents and new strategic approaches for enzyme delivery to highlight the most relevant aspects, concerning next generation LSDs treatment.

Hypertrophic cardiomyopathy in pompe disease is not limited to the classic infantile-onset phenotype.

Pompe disease is a genetic disorder caused by a deficiency of acid α-glucosidase (GAA). Patients with classic infantile-onset Pompe disease usually present with hypertrophic cardiomyopathy and die before 1 year of age, if not treated with enzyme replacement therapy (ERT). In comparison, patients with late-onset Pompe disease typically do not have hypertrophic cardiomyopathy. However, here we describe five patients who presented with hypertrophic cardiomyopathy but did not fit the criteria of classic infantile-onset Pompe disease. Their ages at diagnosis of cardiomyopathy were 1 month in two patients following detection of an audible cardiac murmur and 2-3 years in the three remaining patients. All patients survived for 5-8 years without ERT. Three patients died before the advent of ERT from causes other than congestive heart failure. One patient had a good response to ERT starting at 5 years of age. The sibling of one patient, who did not receive ERT and died at age seven, was diagnosed prenatally. At 3months of age, the sibling had hypertrophic cardiomyopathy, and a muscle biopsy at that time revealed glycogen accumulation.This case series demonstrates that Pompe disease is a continuum of disease, and the development of cardiomyopathy is not limited to classic infantile-onset Pompe disease. These patients do not fit into the discrete phenotypes of infantile- or late-onset Pompe disease, which may suggest reconsidering the nomenclature of Pompe disease.

Enzyme Replacement in Neuronal Storage Disorders in the Pediatric Population

In the past 15years, for select lysosomal storage diseases, there has been a shift from symptom management to disease modification in terms of treatment strategy, mainly related to use of enzyme replacement therapy (ERT). Yet the application of ERT is for very few diseases, and while beneficial, ERT does not represent a cure. For some disorders, the advent of ERT has made a dramatic impact, while for others, benefits have been much more modest. Understanding of the long-term effects as well as the appropriate time for initiation of ERT is under exploration in a number of diseases, while the feasibility of ERT is still being established for others. No definite effects of ERT on central nervous system manifestations of lysosomal storage diseases have been observed for any disease to date. New strategies, including intrathecal enzyme replacement, gene therapy and substrate reduction therapy are being developed in animal models and clinical trials, which hopefully will begin a new era of nervous system disease modification in neuronal storage disorders.

Pompe’s Disease in Siblings Taking Enzyme Replacement Therapy: Skeletal Muscle Magnetic Resonance Imaging Findings

Pompe’s disease is a rare inherited muscle disorder resulting from deficiency of lysosomal acid α-glucosidase. This report describes the muscle magnetic resonance imaging findings in two young adults with late-onset Pompe’s disease. A specific pattern of muscle involvement has been described in multiple inherited muscle disorders, including Pompe’s disease. With the advent of enzyme replacement therapy, increased utilisation of imaging for diagnosis, monitoring of disease progress, and treatment response are expected. This article emphasises the importance of magnetic resonance imaging in screening the skeletal muscle in this disease and describes the development of new imaging techniques.

Therapeutic advances in the management of Pompe disease and other metabolic myopathies

The world of metabolic myopathies has been dramatically modified by the advent of enzyme replacement therapy (ERT), the first causative treatment for glycogenosis type II (GSDII) or Pompe disease, which has given new impetus to research into that disease and also other pathologies. This article reviews new advances in the treatment of GSDII, the consensus about ERT, and its limitations. In addition, the most recent knowledge regarding the pathophysiology, phenotype, and genotype of the disease is discussed. Pharmacological, immunotherapy, nutritional, and physical/rehabilitative treatments for late-onset Pompe disease and other metabolic myopathies are covered, including treatments for defects in glycogen metabolism, such as glycogenosis type V (McArdle disease), and glycogenosis type III (debrancher enzyme deficiency), and defects in lipid metabolism, such as carnitine palmitoyltransferase II deficiency and electron transferring flavoprotein dehydrogenase deficiency, or riboflavin-responsive multiple acyl-CoA dehydrogenase deficiency.

CRIM-negative Pompe disease patients with satisfactory clinical outcomes on enzyme replacement therapy

Pompe disease, especially in its infantile form, is a fatal disease. Most of the patients with this disease synthesize a nonfunctional form of the enzyme alpha glucosidase (GAA), the deficient enzyme in this disease. Patients producing some amount of this protein are labeled as cross-reactive immunologic material (CRIM)-positive. Few of them are unable to synthesize it and are labeled CRIM-negative. The clinical course of the disease has changed with the advent of enzyme replacement therapy (ERT) with recombinant alpha glucosidase enzyme (rhGAA). However, CRIM-negative patients have always been known to have poor outcome on ERT due to the development of anti-rhGAA antibodies in their bodies that neutralizes ERT efficacy. Here, we describe two CRIM-negative siblings on rhGAA ERT with unusually low anti-rhGAA antibody titer and good clinical outcome. Up to our current knowledge, this is the first report that describes such a good response to ERT in CRIM-negative patients.

Gaucher Disease: A Comprehensive Review

Gaucher disease (GD) is an inherited error of metabolism due to a deficiency of glucocerebrosidase. This leads to excessive storage of glucocerebroside in the liver, spleen, bone, and bone marrow. Patients develop anemia, thrombocytopenia, hepatosplenomegaly, bone infarcts, aseptic necrosis of bone, and osteoporosis. There are three types of GD; types 2 and 3 have neurological involvement. With the advent of enzyme replacement therapy and substrate reduction therapy, the natural history of the disease has been has significantly changed, with a marked decrease in morbidity, especially for type 1 patients. This article reviews a broad spectrum of information regarding Gaucher disease, from the history of the disease to newer therapies still in the investigational stage.