Treatment Of Gaucher Disease Research Articles

Therapeutic potential of histone deacetylase inhibitor for treatment of Niemann-Pick type C1 disease

Background Niemann-Pick type C (NPC) is a rare, autosomal recessive neurodegenerative lysosomal storage disorder (LSD) caused due to mutation in either npc1 or npc2 genes. However, 95% of the reported cases are caused due to mutation in npc1 gene and only 5% due to the mutation in npc2 gene. Mutations in either of these two genes results in similar phenotype such that there is an abnormal accumulation of unesterified cholesterol and glycosphingolipids in late endosomes/ lysosomes (LE/Ly) of many cell types. NPC1 is a multi-spanning transmembrane protein localized in limiting membrane of LE/Ly whereas NPC2 is soluble cholesterol binding protein localized in the lumen of LE/Ly. There are no therapeutic options to treat the disease and the children born with this defect die before the age of 20 years. Miglustat, a drug used to treat Gaucher disease has been reported to stabilize NPC patients and has also been approved for treating NPC patients in Europe. Infusion of very high dose of chemical chaperone like 2-hydroxypropyl-b-cyclodextrin (HPBCD) several times a week has also been shown to reduce the cholesterol load in peripheral tissues. Unfortunately, the blood brain barrier (BBB) cross over capability of HPCD is very poor and hence requires intrathecal CNS injections.

Glycosylation and functionality of recombinant β-glucocerebrosidase from various production systems

The glycosylation of recombinant β-glucocerebrosidase, and in particular the exposure of mannose residues, has been shown to be a key factor in the success of ERT (enzyme replacement therapy) for the treatment of GD (Gaucher disease). Macrophages, the target cells in GD, internalize β-glucocerebrosidase through MRs (mannose receptors). Three enzymes are commercially available for the treatment of GD by ERT. Taliglucerase alfa, imiglucerase and velaglucerase alfa are each produced in different cell systems and undergo various post-translational or post-production glycosylation modifications to expose their mannose residues. This is the first study in which the glycosylation profiles of the three enzymes are compared, using the same methodology and the effect on functionality and cellular uptake is evaluated. While the major differences in glycosylation profiles reside in the variation of terminal residues and mannose chain length, the enzymatic activity and stability are not affected by these differences. Furthermore, the cellular uptake and in-cell stability in rat and human macrophages are similar. Finally, in vivo studies to evaluate the uptake into target organs also show similar results for all three enzymes. These results indicate that the variations of glycosylation between the three regulatory-approved β-glucocerebrosidase enzymes have no effect on their function or distribution.

Gaucher Disease and Its Treatment Options

To review the epidemiology, pathophysiology, and treatments of Gaucher disease (GD), focusing on the role of enzyme replacement therapy (ERT), andsubstrate reduction therapy (SRT). A literature search through PubMed (1984-May 2013) of English language articles was performed with terms: Gaucher's disease, lysosomal storage disease. Secondary and tertiary references were obtained by reviewing related articles. All articles in English identified from the data sources, clinical studies using ERT, SRT and articles containing other interesting aspects were included. GD is the most common inherited LSD, characterized by a deficiency in the activity of the enzyme acid β-glucosidase, which leads to accumulation of glucocerebroside within lysosomes of macrophages, leading to hepatosplenomegaly, bone marrow suppression, and bone lesions. GD is classified into 3 types: type 1 GD (GD1) is chronic and non-neuronopathic, accounting for 95% of GDs, and types 2 and 3 (GD2, GD3) cause nerve cell destruction. Regular monitoring of enzyme chitotriosidase and pulmonary and activation-regulated chemokines are useful to confirm the diagnosis and effectiveness of GD treatment. There are 4 treatments available for GD1: 3 ERTs and 1 SRT. Miglustat, an SRT, is approved for mild to moderate GD1. ERTs are available for moderate to severe GD1 and can improve quality of life within the first year of treatment. The newest ERT, taliglucerase alfa, is plant-cell derived that can be produced on a large scale at lower cost. Eliglustat tartrate, another SRT, is under phase 3 clinical trials. No drugs have been approved for GD2 or GD3.

Response to the Letter: Allogeneic Hematopoietic Stem Cell Transplantation for Treatment of Gaucher Disease

This is our response to the letter to the editor from Dr. Machaczka on our recent review paper titled “Gaucher's disease—a reappraisal of hematopoietic stem cell transplantation.”

New Insights into the Pharmacological Chaperone Activity of C2‐Substituted Glucoimidazoles for the Treatment of Gaucher Disease

Mutations in acid β-glucocerebrosidase (GCase) lead to the accumulation of the sphingolipid glucosylceramide, thereby resulting in Gaucher disease (GD). Active-site-specific competitive GCase inhibitors are effective pharmacological chaperones (PCs) that act as folding agents for mutant GCase folding in the endoplasmic reticulum. In this study, we prepared a series of glucoimidazole C2-substituent derivatives, and evaluated their inhibition and PC properties with GCase. A cell-based assay with patient-derived lymphoblasts (N370S or L444P mutations) demonstrated that administration of these compounds can significantly increase GCase activity. Interestingly, the 3,3-dimethyl-N-phenyl-4-amide-1-butyl-substituted moderate inhibitor 11 had the greatest effect on activity: 2.1-fold increase in N370S lymphoblasts at 2.5 μM and 1.2-fold increase in L444P at 0.5 μM following a three-day incubation. Computer docking studies and a protease protection assay were used to elucidate the ligand-enzyme interactions responsible for the chaperone activity of 11. Western blot and immuno-fluorescence assays verified restoration of GCase trafficking to the lysosome. Together, these results indicate that 11 is a promising PC for GD treatment and provide direct evidence of the mechanism of GCase chaperoning.

Molecular Basis and Clinical Management of Gaucher Disease

Gaucher disease (GD) type I is an autosomal recessive disease caused by a genetic deficiency of lysosomal β-glucocerebrosidase that leads to accumulation of undergraded substrate glucocerebroside and other glycolipids, thus causing damage in different organs. GBA is the only gene in which mutations are known to cause GD. Nearly 300 mutations have been identified in GD patients, including frame-shift mutations, point mutations, deletions, insertions, splice site mutations and recombinants. The variety of phenotypes associated to GD shows imperfect correlation with mutations. GD encompasses a spectrum of clinical findings from a perinatal lethal form to an asymptomatic form. However the classification of GD by clinical subtype is still useful in describing the wide range of clinical findings and broad variability in presentation. Three major clinical types are delineated: type I (chronic nonneuropathic), type II (acute neuropathic), and type III (chronic neuropathic). Patients with type I GD present with visceromegaly, hematological complications, and bone disease. Cardiac and pulmonary complications are rare. Type I GD adult patients have elevated risk of malignancies, Parkinson’s disease or Parkinsonism. Neuropathic forms of GD are rare and clinically ranging from lethal perinatal form to very mild form limited to abnormalities of horizontal ocular saccades. Diagnosis of acid β-glucosylceramidase relies on enzyme activity in peripheral blood leukocytes or skin fibroblasts and/or identification of GBA mutations. Enzyme replacement therapy is an effective treatment for non-neuropathic GD. Substrate inhibitor is the alternative therapy for some patients with GD is miglustat, iminosugar inhibitor of glucocerebroside synthase.

A multicenter, double-blind, randomized safety and efficacy study of two dose levels of taliglucerase alfa in pediatric patients with Gaucher disease

In the treatment of Gaucher disease (GD), early intervention with enzyme replacement therapy (ERT) is crucial in prevention of irreversible pathology. Taliglucerase alfa is a plant cell–expressed beta-glucocerebrosidase ERT that is approved in the USA, Israel, and Uruguay for treatment of GD in adults. The aim of this multicenter, double-blind, dose-ranging (30 and 60 U/kg), 12-month study was to investigate the safety and efficacy of taliglucerase alfa in pediatric GD patients aged 2 to <18 years. Primary efficacy variable: median percent change in hemoglobin concentration from baseline. Secondary variables: percent changes in spleen/liver volumes, platelet counts, and chitotriosidase activity. After completion of the 12-month study, patients were eligible to enter a 2-year extension. Eleven patients (nine, type 1; two, type 3) were randomized to taliglucerase alfa 30 or 60 U/kg. Progressive improvement was demonstrated in hemoglobin, spleen volume, liver volume, platelet count, and chitotriosidase activity. At 12 months, composite analysis of both dose groups revealed that mean hemoglobin and platelets were increased by 14.7% and 50.3%, respectively, from baseline, and absolute spleen and liver volumes were reduced 34.2% and 9.8%, respectively, from baseline. The majority (96.2%) of adverse events (AEs) were mild or moderate, 15.1% were reported as treatment related, and one related serious AE was reported (patient continues on treatment). There were no unexpected AEs and all treatment-related AEs were transient in nature. Taken together, as previously seen for adult patients with GD, data suggest that taliglucerase alfa has the potential to provide an alternative therapy in pediatric patients.

Heparan sulphate inhibits CXCL12-mediated hematopoietic cell migration and engraftment in mucopolysaccharidosis type I mice

reduced 50% of their normal therapeutic dosage of imiglucerase. After 6–12 month, 9 of them switched to velaglucerase alfa treatment. They have been followed for more than 12 months since drug switching. Clinic, biochemical and imaging parameters have been evaluated every 3–6 months. Velaglucerase alfa was administered at the dosage preceding the shortage period (range 60 to 94 U/kg/month). Results: Imiglucerase reduction was generally well tolerated in the majority of the patients, while only few showed GD symptoms recurrence (mainly asthenia and bone pain). One year after enzyme switch, asthenia improved in all patients and bone pain in two of them. At biochemical level, hemoglobin increased in 3 patients and platelet in 1 patient. Imaging analysis of organ volumes and femurs storage did not show significant modifications. No side effects were recorded. Conclusions: Velaglucerase alfa demonstrated to be an effective therapeutic alternative to imiglucerase in treating Gaucher disease.

Long-term safety and efficacy data of taliglucerase alfa, a Plant cell-expressed recombinant glucocerebrosidase, in the treatment of naïve Gaucher disease patients: 36-Month Results

Taliglucerase alfa is a beta-glucocerebrosidase enzyme replacement therapy (ERT) that is approved in the USA, Israel, and Uruguay for the treatment of Gaucher disease (GD) in adults, and is the first approved plant cell–expressed biotherapeutic. Pivotal study PB-06-001 was a 9-month, randomized, doubleblind, dose-ranging (30 and 60 U/kg) trial to assess the safety and efficacy of taliglucerase alfa in treatment-naive GD patients. Primary outcome measure was change from baseline in spleen volume, while secondary outcome measures included change from baseline in liver volumes, platelet counts, hemoglobin levels, and chitotriosidase activity. Key inclusion criteria were splenomegaly >8 multiples of normal (MN) and platelet counts <120,000/mm 3 . At the completion of the 9-month study, patients were eligible to enter an open-label extension study, PB-06-003, with taliglucerase alfa given every 2 weeks at the same dose as in study PB-06-001. Twenty-six treatment-naive GD patients from study PB06-001 continued double-blind treatment in study PB06-003. This interim analysis presents results for 23 patients that completed 27 months in PB-06-003 for a total of 36 months of taliglucerase alfa treatment. Mean spleen volume was reduced from 16.4/17.8 MN to 8.1/5.6 MN, liver volume was reduced from 1.7/1.5 to 1.3/1.1 MN, and chitotriosidase activity was reduced by 73.5% and 83.0% for 30 U/kg and 60 U/kg, respectively. Hemoglobin concentration and platelet counts were also improved. All treatment-related adverse events were mild or moderate in severity and transient in nature.

Use of the L-idonojirimycin derivatives as pharmacological chaperones for the treatment of Gaucher disease

who are also responsible for defining and coordinating research directions and funding pursuits. To provide a precisely defined basis for further research, we are also developing, in parallel, a framework for the ethical acquisition and secure storage of patient DNA samples. This expanded database of clinical, biochemical and genetic data will facilitate more opportunities for research aimed at the improvement of existing treatments and further supports the search for new therapeutic targets. Overall, thisMorquioBetter Project, which is funded by a patient support group, unites clinicians and scientists around the world, enhancing knowledge transfer and translation into better care and improved outcomes of affected patients.

The chaperone activity and toxicity of ambroxol on Gaucher cells and normal mice

Gaucher disease (GD), caused by a defect of acid β-glucosidase (β-Glu), is one of the most common sphingolipidoses. Recently, ambroxol, an FDA-approved drug used to treat airway mucus hypersecretion and hyaline membrane disease in newborns, was identified as a chemical chaperone for GD. In the present study, we investigated the chaperone activity and toxicity of ambroxol on both cultured GD patient cells and normal mice. We found that ambroxol treatment significantly increased N370S, F213I, N188S/G193W and R120W mutant β-Glu activities in GD fibroblasts with low cytotoxicity. Additionally, we measured the β-Glu activity in the tissues of normal mice which received water containing increasing concentrations of ambroxol ad libitum for one week. No serious adverse effect was observed during this experiment. Ambroxol significantly increased the β-Glu activity in the spleen, heart and cerebellum of the mice. This result showed its oral availability and wide distribution and chaperone activity in the tissues, including the brain, and its lack of acute toxicity. These characteristics of ambroxol would make it a potential therapeutic chaperone in the treatment of GD with neurological manifestations.

Imiglucerase in the treatment of Gaucher disease: a history and perspective.

The scientific and therapeutic development of imiglucerase (Cerezyme®) by the Genzyme Corporation is a paradigm case for a critical examination of current trends in biotechnology. In this article the authors argue that contemporary interest in treatments for rare diseases by major pharmaceutical companies stems in large part from an exception among rarities: the astonishing commercial success of Cerezyme. The fortunes of the Genzyme Corporation, latterly acquired by global giant Sanofi SA, were founded on the evolution of a blockbuster therapy for a single but, as it turns out, propitious ultra-orphan disorder: Gaucher disease.

Remodeling the oligosaccharides on β-glucocerebrosidase using hydrophobic interaction chromatography and applications of hydroxyl ethyl starch for improving remodeling and enhancing protein stability

In this article, we describe a hydrophobic interaction chromatography (HIC) method to remodel the carbohydrates on recombinant human β-glucocerebrosidase (GCR) and the use of hydroxyl ethyl starch (HES) an ethylated starch polymer, to improve this process. GCR is a therapeutic protein used in the treatment of Gaucher disease, a life threatening condition in which patients lack sufficient functional levels of this enzyme. Gaucher disease is the most common inherited lysosomal storage disorder resulting in hepatomegaly, splenomegaly, and bone and lung pathology due to the accumulation of glucosylceramide in the lysosomes of macrophages (Beutler and Grabowski, 2001). The oligosaccharide remodeling of GCR, performed on HIC using three enzymes that remove sugars, increases macrophage uptake through the mannose receptor and thereby lowers its therapeutic dose versus unmodified GCR (Furbish et al., 1981; Van Patten et al., 2007). In this article we describe findings that the addition of HES lowered the amounts of three deglycosylating enzymes needed for remodeling GCR. HES also stabilized the activity of α-glucosidase, α-galactosidase, and GCR under conditions in which these three enzymes rapidly lose activity in the absence of this polymer. Circular dichroism (CD) and second derivative UV spectroscopy revealed that the secondary and tertiary structure of α-glucosidase was unchanged while for GCR there was a slight compaction of the secondary structure but no apparent affect on the tertiary structure. The thermal stability of both GCR and α-glucosidase were enhanced by HES as both molecules showed an increased transition midpoint (T(m)).

Histone deacetylase inhibitors prevent the degradation and restore the activity of glucocerebrosidase in Gaucher disease

Gaucher disease (GD) is caused by a spectrum of genetic mutations within the gene encoding the lysosomal enzyme glucocerebrosidase (GCase). These mutations often lead to misfolded proteins that are recognized by the unfolded protein response system and are degraded through the ubiquitin-proteasome pathway. Modulating this pathway with histone deacetylase inhibitors (HDACis) has been shown to improve protein stability in other disease settings. To identify the mechanisms involved in the regulation of GCase and determine the effects of HDACis on protein stability, we investigated the most prevalent mutations for nonneuronopathic (N370S) and neuronopathic (L444P) GD in cultured fibroblasts derived from GD patients and HeLa cells transfected with these mutations. The half-lives of mutant GCase proteins correspond to decreases in protein levels and enzymatic activity. GCase was found to bind to Hsp70, which directed the protein to TCP1 for proper folding, and to Hsp90, which directed the protein to the ubiquitin-proteasome pathway. Using a known HDACi (SAHA) and a unique small-molecule HDACi (LB-205), GCase levels increased rescuing enzymatic activity in mutant cells. The increase in the quantity of protein can be attributed to increases in protein half-life that correspond primarily with a decrease in degradation rather than an increase in chaperoned folding. HDACis reduce binding to Hsp90 and prevent subsequent ubiquitination and proteasomal degradation without affecting binding to Hsp70 or TCP1. These findings provide insight into the pathogenesis of GD and indicate a potent therapeutic potential of HDAC inhibitors for the treatment of GD and other human protein misfolding disorders.

Guía de actuación en pacientes con enfermedad de Gaucher tipo 1

Gaucher's disease (GD) is an inborn error of metabolism of the lysosomal enzyme beta-glucosidase, which induces the deposition of undegraded glycolipid material in organs rich in mononuclear macrophage system including liver, spleen and bone marrow. Beta-glucosidase is suspected in patients with evidence of liver and/or spleen enlargement, anemia and/or thrombocytopenia not attributable to other causes, or bone crisis especially in children. In scarce cases GD is associated with neurological involvement. The diagnosis confirmation is performed by analysis of beta-glucosidase activity in peripheral blood leukocytes or fibroblasts. It is necessary to identify genetic mutations that cause GD. It is also advisable to identify biomarkers including chitotriosidase activity and plasma CCL-18/PARC concentration. The use of a protocol for assessing the intensity of the deposit is mandatory to establish the indication for treatment, especially in rare diseases. Nowadays there are several options for treatment of GD: enzyme replacement therapy and substrate reduction therapy. Regular assessments are needed to establish the response and the degree of achievement of the therapeutic goals recommended through expert consensus.

VP22 enhances the expression of glucocerebrosidase in human Gaucher II fibroblast cells mediated by lentiviral vectors

Gaucher disease is an autosomal recessive lysosomal storage disorder resulting in a deficiency of glucocerebrosidase (GC). Imiglucerase, a recombinant form of GC, has been successfully used in the treatment of Gaucher disease and has been shown to be a good potential candidate for gene therapy. However, its low transduction efficiency and short duration of expression have limited it as a gene therapy strategy. VP22, the herpes simplex virus type I tegument protein, is known to facilitate intercellular protein transport, thus making it a promising tool for improving gene transfer efficiency. To investigate whether the fusion of VP22 to GC could improve its therapeutic efficiency for Gaucher disease, the lentiviral vectors pHIV-GC and pHIV-VP(22)-GC were constructed and confirmed by PCR or RT-PCR. After packaging, the vectors were transduced into human Gaucher II fibroblast cells (GII cells). Flow cytometric analysis revealed that the GC expression rates in lenti-VP(22)-GC-transduced GII cells were higher by comparison than those in lenti-GC-transduced GII cells. A Western blot demonstrated higher levels of GC protein expression in lenti-VP(22)-GC-transduced GII cells. In addition, the long-term expression levels and increased GC activities in lenti-VP(22)-GC-transduced GII cells were also observed. These data implicate that VP22-mediated effects may be useful for enhancing the efficacy of this Gaucher disease treatment.

How I treat Gaucher disease

AbstractThis review presents a cohesive approach to treating patients with Gaucher disease. The spectrum of the clinical presentation of the disease is broad, yet heretofore there was only one disease-specific treatment. In the past 2 years, a global shortage of this product has resulted in reassessment of the “one enzyme–one disease–one therapy” mantra. It has also showcased the multiple levels that engage the patient, the treating physician, and the third-party insurer in providing adequate treatment to all symptomatic patients. The key points summarizing the way I manage my patients include accurate enzymatic diagnosis with mutation analysis (for some prognostication and better carrier detection in the family), a detailed follow-up every 6-12 months (with an option to see consultants and attention to comorbidities), and initiation of enzyme replacement therapy according to symptoms or deterioration in clinically significant features or both. I do not treat patients with very mild disease, but I consider presymptomatic therapy for patients at risk, including young women with poor obstetric history. I prefer the minimal-effective dose rather than the maximally tolerated dose, and when the difference between high-dose and lower-dose regimens is (merely statistically significant but) clinically meaningless, minimizing the burden on society by advocating less-expensive treatments is ethically justified.

Pharmacological chaperone therapy for Gaucher disease: a patent review

Introduction: Mutations in the gene encoding for acid β-glucosidase (β-glucocerebrosidase, GlcCerase) are seen in Gaucher disease (GD), which give rise to significant protein misfolding effects and result in progressive accumulation of glucosyl ceramide. The main treatment for GD is enzyme replacement therapy (ERT). The iminosugar glycosidase inhibitor N-(n-butyl)-1-deoxynojirimycin (miglustat, Zavesca™) is used in a second treatment modality known as substrate reduction therapy. At the beginning of the 21st century, a third therapeutic paradigm was launched, namely, pharmacological chaperone therapy (PCT). This therapeutic strategy relies on the capability of such inhibitors to promote the correct folding and stabilize mutant forms of lysosomal enzymes, such as GlcCerase, as they pass through the secretory pathway.Areas covered: This review summarizes the different approaches used to implement the concept of PCT for GD. It discusses the relevant research, patents and patent applications filed in the last decade.Expert opinion: While the significance of PCT remains a matter of debate, the great interest gathered regarding it in a relatively few years reflects its broad potential scope, well beyond GD. The fact that pharmacological chaperones can be designed to cross the blood brain barrier (BBB) make them candidates for the treatment of neuronopathic forms of GD that are not responsive to ERT. Combined therapies offer even broader possibilities that deserve to be fully explored.

Velaglucerase alfa: A new option for Gaucher disease treatment

Type 1 Gaucher disease (GD) results from inherited β-glucocerebrosidase gene mutations, leading to anemia, thrombocytopenia, splenomegaly, hepatomegaly and skeletal disease. Velaglucerase alfa is a β-glucocerebrosidase produced by gene activation in a human cell line, and indicated for type 1 GD. A phase I/II clinical trial (TKT025; N = 12), its ongoing extension (TKT025EXT) and three phase III trials (total N = 82), showed that velaglucerase alfa is generally well tolerated in adult and pediatric patients. Many disease-related parameters improved significantly in two phase III trials in treatment-naïve patients, and were successfully maintained in imiglucerase-experienced patients in a phase II/III switch study. Ten adults in TKT025EXT sustained improvements through 5 years, including bone mineral density. Comparison with imiglucerase shows that velaglucerase alfa is an effective, generally well-tolerated alternative enzyme replacement therapy. In vitro data suggest velaglucerase alfa may be internalized into cells more efficiently and have a lower rate of seroconversion. However, these results do not necessarily correlate with clinical efficacy.

Molecular Basis of Reduced Glucosylceramidase Activity in the Most Common Gaucher Disease Mutant, N370S

Gaucher disease is caused by the defective activity of the lysosomal hydrolase, glucosylceramidase. Although the x-ray structure of wild type glucosylceramidase has been resolved, little is known about the structural features of any of the >200 mutations. Various treatments for Gaucher disease are available, including enzyme replacement and chaperone therapies. The latter involves binding of competitive inhibitors at the active site to enable correct folding and transport of the mutant enzyme to the lysosome. We now use molecular dynamics, a set of structural analysis tools, and several statistical methods to determine the flexible behavior of the N370S Gaucher mutant at various pH values, with and without binding the chaperone, N-butyl-deoxynojirimycin. We focus on the effect of the chaperone on the whole protein, on the active site, and on three important structural loops, and we demonstrate how the chaperone modifies the behavior of N370S in such a way that it becomes more active at lysosomal pH. Our results suggest a mechanism whereby the binding of N-butyl-deoxynojirimycin helps target correctly folded glucosylceramidase to the lysosome, contributes to binding with saposin C, and explains the initiation of the substrate-enzyme complex. Such analysis provides a new framework for determination of the structure of other Gaucher disease mutants and suggests new approaches for rational drug design.