Pegunigalsidase alfa, a novel PEGylated, covalently crosslinked form of α‐galactosidase A developed as enzyme replacement therapy (ERT) for Fabry disease (FD), was designed to increase plasma ...half‐life and reduce immunogenicity, thereby enhancing efficacy compared with available products. Symptomatic adults with FD participated in this open‐label, 3‐month dose‐ranging study, followed by a 9‐month extension. Three cohorts were enrolled in a stepwise manner, each receiving increased doses of pegunigalsidase alfa: 0.2, 1.0, 2.0 mg/kg, via intravenous infusion every other week. Pharmacokinetic analysis occurred on Day 1 and Months 3, 6, and 12. Kidney biopsies at baseline and Month 6 assessed peritubular capillary globotriaosylceramide (Gb3) content. Renal function, cardiac parameters, and other clinical endpoints were assessed throughout. Treatment‐emergent adverse events (AEs) and presence of immunoglobulin G (IgG) antidrug antibodies (ADAs) were assessed. Sixteen patients completed 1 year's treatment. Mean terminal plasma half‐life (each cohort) ranged from 53 to 121 hours. All 11 male and 1 of 7 female patients presented with classic FD phenotype, in whom renal peritubular capillary Gb3 inclusions were reduced by 84%. Mean estimated glomerular filtration rate was 111 mL/min/1.73 m2 at baseline, remaining stable throughout treatment. Three patients developed treatment‐induced IgG ADAs; following 1 year's treatment, all became ADA‐negative. Nearly all treatment‐emergent AEs were mild or moderate. One patient withdrew from the study following a serious related AE. Pegunigalsidase alfa may represent an advance in ERT for FD, based on its unique pharmacokinetics and apparent low immunogenicity.
Gaucher disease (GD) stands as one of the most prevalent lysosomal disorders, yet neuronopathic GD (nGD) is an uncommon subset characterized by a wide array of clinical manifestations that complicate ...diagnosis, particularly when neurological symptoms are understated. nGD may manifest as the acute neuronopathic type, or GD type 2 (GD2), either prenatally or within the first weeks to months of life, whereas GD type 3 (GD3) symptoms may emerge at any point during childhood or occasionally in adolescence. The clinical presentation encompasses severe systemic involvement to mild visceral disease, often coupled with a spectrum of progressive neurological signs and symptoms such as cognitive impairment, ataxia, seizures, myoclonus, varying degrees of brainstem dysfunction presenting with stridor, apneic episodes, and/or impaired swallowing. This manuscript aims to provide a comprehensive review of the incidence, distinctive presentations, and diverse clinical phenotypes of nGD across various countries and regions. It will explore the natural history of the neurodegenerative process in GD, shedding light on its various manifestations during infancy and childhood, and offer insights into the diagnostic journey, the challenges faced in the clinical management, and current and investigative therapeutic approaches for GD's neurological variants.
Migalastat stabilizes mutant α-galactosidase in Fabry's disease, reducing globotriaosylceramide deposition. In this study, the percentage of patients with a decrease of 50% or more in kidney ...interstitial capillary deposition at 6 months was similar in the migalastat and placebo groups.
Fabry’s disease is a rare, progressive, and devastating X-linked disorder caused by the functional deficiency of lysosomal α-galactosidase.
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The resultant accumulation of glycosphingolipids, predominantly globotriaosylceramide (GL-3), can lead to multisystem disease and early death.
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Binding of the pharmacologic chaperone migalastat to the active site of α-galactosidase stabilizes certain mutant enzymes, thus facilitating proper trafficking to lysosomes, where dissociation of migalastat allows α-galactosidase to catabolize accumulated substrates.
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In patients with mutant enzymes that are identified with the validated assay, orally administered migalastat may be an alternative treatment option for addressing certain unmet medical needs associated with enzyme-replacement therapy — for . . .
The definition of neuronopathic Gaucher disease Schiffmann, Raphael; Sevigny, Jeff; Rolfs, Arndt ...
Journal of inherited metabolic disease,
September 2020, Letnik:
43, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Neuronopathic Gaucher disease (nGD) has a very wide clinical and genotypic spectrum. However, there is no consensus definition of nGD, including no description of how best to diagnostically separate ...the acute form—Gaucher type 2—from the subacute or chronic form—Gaucher type 3. In this article, we define the various forms of Gaucher disease with particular emphasis on the presence of gaze palsy in all patients with nGD. This consensus definition will help in both clinical diagnosis and appropriate patient recruitment to upcoming clinical trials.
New Directions in Gaucher Disease Horowitz, Mia; Elstein, Deborah; Zimran, Ari ...
Human mutation,
November 2016, Letnik:
37, Številka:
11
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
In Gaucher disease (GD), mutant lysosomal acid β‐glucocerebrosidase fails to properly hydrolyze its substrate, glucosylceramide, which accumulates in the lysosomes. Due to its phenotypic ...heterogeneity, GD has been classified into type 1, non‐neuronopathic, and types 2 and 3, the neuronopathic forms, based on the primary involvement of the central nervous system. Neuroinflammation and necroptotic death may appear in the neuronopathic forms of GD, whereas type 1 GD patients may develop Parkinson disease (PD), a prototype of protein misfolding disorders of the nervous system. PD is significantly more prevalent among GD carriers and patients than among the non‐GD populations. It is apparent that the amount of mutant enzyme present in lysosomes depends on the amount of mutant enzyme recognized as correctly folded in the endoplasmic reticulum (ER) for physiologically correct transport through the Golgi apparatus to the lysosome. Mutant enzyme recognized as misfolded is retained in the ER, inducing the Unfolded Protein Response. In the current review, we present three discrete areas of interest: molecular and cellular mechanisms underlying the association between GD and PD; the clinical and genetic associations between GD and PD; and treatment options for GD. We also discuss the relevance of induced pleuripotent stem cells to the above associations.
In the present review we focus on four areas of interest: Cellular disfunction in Gaucher disease; The association of Gaucher disease with Parkinson disease; Treatment modalities in Gaucher disease and the use of induced pleuripotent stem cells to study Gaucher disease.
Background
Gaucher disease (GD) presents with a range of signs and symptoms. Physicians can fail to recognise the early stages of GD owing to a lack of disease awareness, which can lead to ...significant diagnostic delays and sometimes irreversible but avoidable morbidities.
Aim
The Gaucher Earlier Diagnosis Consensus (GED‐C) initiative aimed to identify signs and co‐variables considered most indicative of early type 1 and type 3 GD, to help non‐specialists identify ‘at‐risk’ patients who may benefit from diagnostic testing.
Methods
An anonymous, three‐round Delphi consensus process was deployed among a global panel of 22 specialists in GD (median experience 17.5 years, collectively managing almost 3000 patients). The rounds entailed data gathering, then importance ranking and establishment of consensus, using 5‐point Likert scales and scoring thresholds defined a priori.
Results
For type 1 disease, seven major signs (splenomegaly, thrombocytopenia, bone‐related manifestations, anaemia, hyperferritinaemia, hepatomegaly and gammopathy) and two major co‐variables (family history of GD and Ashkenazi‐Jewish ancestry) were identified. For type 3 disease, nine major signs (splenomegaly, oculomotor disturbances, thrombocytopenia, epilepsy, anaemia, hepatomegaly, bone pain, motor disturbances and kyphosis) and one major co‐variable (family history of GD) were identified. Lack of disease awareness, overlooking mild early signs and failure to consider GD as a diagnostic differential were considered major barriers to early diagnosis.
Conclusion
The signs and co‐variables identified in the GED‐C initiative as potentially indicative of early GD will help to guide non‐specialists and raise their index of suspicion in identifying patients potentially suitable for diagnostic testing for GD.
The major cellular clearance pathway for organelle and unwanted proteins is the autophagy-lysosome pathway (ALP). Lysosomes not only house proteolytic enzymes, but also traffic organelles, sense ...nutrients, and repair mitochondria. Mitophagy is initiated by damaged mitochondria, which is ultimately degraded by the ALP to compensate for ATP loss. While both systems are dynamic and respond to continuous cellular stressors, most studies are derived from animal models or cell based systems, which do not provide complete real time data about cellular processes involved in the progression of lysosomal storage diseases in patients. Gaucher and Fabry diseases are rare sphingolipid disorders due to the deficiency of the lysosomal enzymes; glucocerebrosidase and α-galactosidase A with resultant lysosomal dysfunction. Little is known about ALP pathology and mitochondrial function in patients with Gaucher and Fabry diseases, and the effects of enzyme replacement therapy (ERT). Studying blood mononuclear cells (PBMCs) from patients, we provide in vivo evidence, that regulation of ALP is defective. In PBMCs derived from Gaucher patients, we report a decreased number of autophagic vacuoles with increased cytoplasmic localization of LC3A/B, accompanied by lysosome accumulation. For both Gaucher and Fabry diseases, the level of the autophagy marker, Beclin1, was elevated and ubiquitin binding protein, SQSTM1/p62, was decreased. mTOR inhibition did not activate autophagy and led to ATP inhibition in PBMCs. Lysosomal abnormalities, independent of the type of the accumulated substrate suppress not only autophagy, but also mitochondrial function and mTOR signaling pathways. ERT partially restored ALP function, LC3-II accumulation and decreased LC3-I/LC3-II ratios. Levels of lysosomal (LAMP1), autophagy (LC3), and mitochondrial markers, (Tfam), normalized after ERT infusion. In conclusion, there is mTOR pathway dysfunction in sphingolipidoses, as observed in both PBMCs derived from patients with Gaucher and Fabry diseases, which leads to impaired autophagy and mitochondrial stress. ERT partially improves ALP function.
Hereditary spastic paraplegia (HSP) is a group of disorders with predominant symptoms of lower‐extremity weakness and spasticity. Despite the delineation of numerous genetic causes of HSP, a ...significant portion of individuals with HSP remain molecularly undiagnosed. Through exome sequencing, we identified five unrelated families with childhood‐onset nonsyndromic HSP, all presenting with progressive spastic gait, leg clonus, and toe walking starting from 7 to 8 years old. A recurrent two‐base pair deletion (c.426_427delGA, p.K143Sfs*15) in the UBAP1 gene was found in four families, and a similar variant (c.475_476delTT, p.F159*) was detected in a fifth family. The variant was confirmed to be de novo in two families and inherited from an affected parent in two other families. RNA studies performed in lymphocytes from one patient with the de novo c.426_427delGA variant demonstrated escape of nonsense‐mediated decay of the UBAP1 mutant transcript, suggesting the generation of a truncated protein. Both variants identified in this study are predicted to result in truncated proteins losing the capacity of binding to ubiquitinated proteins, hence appearing to exhibit a dominant‐negative effect on the normal function of the endosome‐specific endosomal sorting complexes required for the transport‐I complex.
In this study, through exome sequencing and interinstitutional data sharing, we identified ubiquitin‐associated protein 1 (MIM# 609787) as a novel disease‐causing gene for autosomal dominant childhood‐onset nonsyndromic hereditary spastic paraplegia in five unrelated families.
Enzyme replacement therapy (ERT) is effective for the treatment of the systemic manifestations of Gaucher disease (GD) and can have a significant impact on skeletal manifestations. Bone involvement ...is broad and can occur in otherwise clinically asymptomatic individuals. The heterogeneity in GD-related bone disease may implicate multiple pathological processes such as disruption of coordinated bone cell activity, in addition to the physical impact of Gaucher cells causing vascular occlusion. Accumulated data suggests that earlier treatment initiation decreases skeletal complications and that bone disease may require a longer duration of treatment and higher dose than is necessary for organ involvement and hematopoietic manifestations. However, in some patients, bone manifestations persist and even worsen despite ERT, regardless of dose or duration of treatment. Treating skeletal disease should be considered of equal importance as treating visceral and hematologic manifestations. When treatment decisions involve multiple enzyme preparations and other therapeutic modalities such small molecules, the choice should be tailored on an individual basis with continuing evaluation.
► In Gaucher disease, bone involvement is broad, occurring in otherwise asymptomatic patients. ► Heterogeneity in Gaucher-related bone disease implicates multiple pathologic processes. ► Treating Gaucher-related bone disease is as important as treating visceral disease. ► Bone disease may respond more slowly and require a different enzyme treatment regimen. ► In some patients, bone manifestations persist or worsen despite enzyme therapy.
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