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Summary Background Pompe disease is a rare disorder characterised by progressive loss of muscle and respiratory function due to acid α-glucosidase deficiency. Enzyme replacement therapy with recombinant human acid α-glucosidase, alglucosidase alfa, is the first approved treatment for the disease, but some patients do not respond, and many do not show a sustained benefit. We aimed to assess the safety and efficacy of an investigational two-component therapy (cipaglucosidase alfa, a novel recombinant human acid α-glucosidase, plus miglustat, an enzyme stabiliser) for late-onset Pompe disease. Methods We did a randomised, double-blind, parallel-group, phase 3 trial at 62 neuromuscular and metabolic medical centres in 24 countries in the Americas, Asia-Pacific, and Europe. Eligible participants were aged 18 years or older with late-onset Pompe disease, and had either been receiving alglucosidase alfa for at least 2 years or were enzyme replacement therapy-naive. Participants were randomly assigned (2:1) using interactive response technology software, stratified by 6-min walk distance and previous enzyme replacement therapy status, to intravenous cipaglucosidase alfa (20 mg/kg) plus oral miglustat or to intravenous alglucosidase alfa (20 mg/kg) plus oral placebo once every 2 weeks for 52 weeks. Patients, investigators, and outcome assessors were masked to treatment assignment. The primary endpoint was change from baseline to week 52 in 6-min walk distance, assessed using a mixed-effect model for repeated measures analysis for comparison of superiority in the intention-to-treat population (all patients who received at least one dose of study drug). This study is now complete and is registered with ClinicalTrials.gov , NCT03729362 . Findings Between Dec 3, 2018, and Nov 26, 2019, 130 patients were screened for eligibility and 125 were enrolled and randomly assigned to receive cipaglucosidase alfa plus miglustat (n=85) or alglucosidase alfa plus placebo (n=40). Two patients in the alglucosidase alfa plus placebo group did not receive any dose due to absence of genotype confirmation of late-onset Pompe disease and were excluded from analysis. Six patients discontinued (one in the alglucosidase alfa plus placebo group, five in the cipaglucosidase alfa plus miglustat group), and 117 completed the study. At week 52, mean change from baseline in 6-min walk distance was 20·8 m (SE 4·6) in the cipaglucosidase alfa plus miglustat group versus 7·2 m (6·6) in the alglucosidase alfa plus placebo group using last observation carried forward (between-group difference 13·6 m [95% CI −2·8 to 29·9]). 118 (96%) of 123 patients experienced at least one treatment-emergent adverse event during the study; the incidence was similar between the cipaglucosidase alfa plus miglustat group (n=81 [95%]) and the alglucosidase alfa plus placebo group (n=37 [97%]). The most frequently reported treatment-emergent adverse events were fall (25 [29%] patients in the cipaglucosidase alfa plus miglustat group vs 15 [39%] in the alglucosidase alfa plus placebo group), headache (20 [24%] vs 9 [24%]), nasopharyngitis (19 [22%] vs 3 [8%]), myalgia (14 [16%] vs 5 [13%]), and arthralgia (13 [15%]) vs 5 [13%]). 12 serious adverse events occurred in eight patients in the cipaglucosidase alfa plus miglustat group; only one event (anaphylaxis) was deemed related to study drug. One serious adverse event (stroke) occurred in the alglucosidase alfa plus placebo group, which was deemed unrelated to study drug. There were no deaths. Interpretation Cipaglucosidase alfa plus miglustat did not achieve statistical superiority to alglucosidase alfa plus placebo for improving 6-min walk distance in our overall population of patients with late-onset Pompe disease. Further studies should investigate the longer-term safety and efficacy of cipaglucosidase alfa plus miglustat and whether this investigational two-component therapy might provide benefits, particularly in respiratory function and in patients who have been receiving enzyme replacement therapy for more than 2 years, as suggested by our secondary and subgroup analyses. Funding Amicus Therapeutics.

Background and purpose Sandhoff disease is a rare type of hereditary (autosomal recessive) GM2-gangliosidosis, which is caused by mutation of the HEXB gene. Disruption of the β subunit of the hexosaminidase (Hex) enzyme affects the function of both the Hex-A and Hex-B isoforms. The severity and the age of onset of the disease (infantile or classic; juvenile; adult) depends on the residual activity of the enzyme. The late-onset form is characterized by diverse symptomatology, comprising motor neuron disease, ataxia, tremor, dystonia, psychiatric symptoms and neuropathy. Methods A 36-year-old female patient has been presenting progressive, symmetrical lower limb weakness for 9 years. Detailed neurological examination revealed mild symmetrical weakness in the hip flexors without the involvement of other muscle groups. The patellar reflex was decreased on both sides. Laboratory tests showed no relevant alteration and routine electroencephalography and brain MRI were normal. Nerve conduction studies and electromyography revealed alterations corresponding to sensory neuropathy. Muscle biopsy demonstrated signs of mild neurogenic lesion. Her younger brother (32-year-old) was observed with similar symptoms. Results Detailed genetic study detected a known pathogenic missense mutation and a 15,088 base pair long known pathogenic deletion in the HEXB gene (NM_000521.4:c.1417G>A; NM_000521:c.-376-5836_669+1473del; double heterozygous state). Segregation analysis and hexosaminidase enzyme assay of the family further confirmed the diagnosis of late-onset Sandhoff disease. Conclusion The purpose of this case report is to draw attention to the significance of late-onset Sandhoff disease amongst disorders presenting with proximal predominant symmetric lower limb muscle weakness in adulthood.

Switching between enzyme replacement therapies (ERT) and substrate reduction therapies (SRT) in patients with type 1 Gaucher disease (GD1) is not uncommon; however, the reasons for switchng treatments have not been explored in detail. Data from the Gaucher Outcome Survey (GOS), an international registry for patients with confirmed GD, were used to evaluate the reasons for, and consequences of, switching between these treatment types. Of the 1843 patients enrolled in GOS on 25 February 2020, 245 had undergone a treatment switch: 222 from initial ERT to SRT (of whom 88 later switched back to ERT) and 23 from initial SRT to ERT. The most common reasons for ERT–SRT switching were duration of infusion (25.4%), drug shortage (22.0%), and adverse events (AEs; 11.9%), and for SRT–ERT switching, AEs (63.6%), lack of beneficial effect (16.4%), and participation in a clinical trial (9.1%). Bodyweight and hematologic parameters largely remained stable before and after switching between ERT and SRT, although with substantial variation between patients. These findings contribute to understanding why treatment switching occurs in patients with GD, and may help physicians recognize the real-world impact of treatment switching between ERT and SRT for patients with GD.

Niemann‐Pick disease type C (NPC) and Tangier disease are genetically and clinically distinct rare inborn errors of metabolism. NPC is caused by defects in either NPC1 or NPC2; whereas Tangier disease is caused by a defect in ABCA1. Tangier disease is currently without therapy, whereas NPC can be treated with miglustat, a small molecule inhibitor of glycosphingolipid biosynthesis that slows the neurological course of the disease. When a Tangier disease patient was misdiagnosed with NPC and treated with miglustat, her symptoms improved. This prompted us to consider whether there is mechanistic convergence between these two apparently unrelated rare inherited metabolic diseases. In this study, we found that when ABCA1 is defective (Tangier disease) there is secondary inhibition of the NPC disease pathway, linking these two diseases at the level of cellular pathophysiology. In addition, this study further supports the hypothesis that miglustat, as well as other substrate reduction therapies, may be potential therapeutic agents for treating Tangier disease as fibroblasts from multiple Tangier patients were corrected by miglustat treatment.

Introduction Fabry disease is a lysosomal storage disorder resulting in multisystemic effects due to deposition and accumulation of glycosphingolipids. Although an X linked disorder, it is recognised that female heterozygotes can express clinical manifestations. Cardiac expression in the female Fabry population remains incompletely understood. Data from the Fabry Outcome Survey suggests that up to a quarter of female patients demonstrate left ventricular hypertrophy (LVH) on echocardiography. Although LVH is the most commonly cited cardiac finding, other abnormalities from clinical surveillance can include electrocardiographic abnormalities, fibrosis and elevated troponin levels. Purpose To establish the prevalence and extent of cardiac involvement amongst our cohort of female Fabry patients. Methods Heterozygous females, confirmed by genetic testing, were identified in our single centre Fabry database. Data was collected retrospectively on their 12 lead ECG, high sensitivity troponin I level and echocardiography performed at their most recent cardiac Fabry clinic visit, along with the most recent cardiac magnetic resonance imaging (CMR). Values are expressed as mean ± SD. Results 51 female heterozygotes were identified, ranging from 23 to 83 years (mean age 49.3±15.4). 28 (54.9%) were established on enzyme replacement therapy. On echocardiography LVH of ≥13mm was identified in 14 (27.5%) patients (mean 14.6±1.9 mm). 44 patients had CMR and of these, 17 (38.6%) had findings in keeping with a Fabry cardiomyopathy (34.1% had fibrosis, 15.9% hypertrophy, 13.6% both). Of the 17 patients with abnormalities on CMR, 8 had normal left ventricular wall thickness on echocardiography. All patients had a high sensitivity troponin I measurement and this was above upper reference limits (>40ng/L) in 21 (41.1%) patients in the absence of chest pain. Of 21 patients with abnormal troponin I levels, 9 had normal left ventricular wall thickness on echocardiography. Abnormalities identified on 12 lead ECG are summarised in Table 1. All patients with ECG abnormalities listed in Table 1 had an abnormal troponin and/or abnormal imaging, except for 5 patients who had an isolated short PR interval. 6 patients had a permanent pacemaker and 1 had a primary prevention implantable cardioverter defibrillator. 25 (49%) of the 51 patients were classed as having cardiac involvement based on raised troponin levels and/or abnormal imaging findings. Conclusion Although Fabry disease is traditionally thought to be a male predominant disease, in our cohort nearly half of our female heterozygotes showed evidence of cardiac involvement. The use of CMR, cardiac biomarkers and 12 lead ECG are helpful adjuncts to identify cardiac involvement, which could otherwise be missed if stand-alone echocardiography was used. Timely identification and monitoring of cardiac involvement has clinical implication, especially with regards to prognosis and treatment. Funding Acknowledgement Type of funding sources: None.

Mesenteric panniculitis is a rare disease caused by idiopathic inflammation of adipose tissue, most commonly affecting the mesentery of the small bowel. We present a unique case of mesenteric panniculitis in a patient with Tangier disease; a rare genetic disorder caused by mutations in the ABCA1 gene, leading to deficiency of high-density lipoprotein in the blood and accumulation of cholesterol esters within various tissues. The accumulation of cholesterol esters in body tissues in patients with Tangier disease may contribute to the pathogenesis of mesenteric panniculitis; although there is limited evidence to support this hypothesis due to the rarity of concurrent disease.

Introduction Fabry disease is an X linked lysosomal storage disorder resulting from deficiency of the enzyme alpha-galactosidase A. Multi-systemic effects are seen due to deposition and accumulation of glycosphingolipids. Although left ventricular hypertrophy is often the most commonly cited cardiac finding, cardiac manifestations can be widely varied, and vascular structural changes with increased thickening of the intima media and progressive vascular dilatation have been observed. Aortic root dilatation in affected males has in the past been reported in up to 30 – 56% using echocardiography, with varying criteria used to define dilatation. Purpose To establish the prevalence of aortic root and ascending aortic dilatation evaluated by echocardiography in our cohort of Fabry patients. Method We identified genotype positive Fabry patients from our single centre Fabry database who underwent echocardiography between January 2019 and January 2021. Data on basic demographics, history of hypertension, cardiac involvement and use of enzyme replacement therapy (ERT) were collected retrospectively. Cardiac involvement was defined as abnormalities detected on echocardiography, cardiovascular magnetic resonance imaging and /or elevated high sensitivity troponin I levels (reference limit >40ng/L for females and >58ng/L for males) not explained by another disease process. Imaging abnormalities included either left ventricular hypertrophy ≥13mm and / or evidence of fibrosis. The maximal aortic root dimension was assessed at the level of the sinus of Valsalva (SOV) and the proximal ascending aorta using echocardiography. Dimensions ≥40 mm, or with a Z3 score >2 (normalised for height by Devereux et al), were classed as dilated. Dimensions are quoted as mean ± standard deviation. Statistical analysis was through Chi-squared testing. Results 82 patients were identified (31 male, 51 female) ages ranging between 23 and 83 years (mean of 51 ± 16.1 years). 21% had treated hypertension (n = 17) and 62% had cardiac involvement from their Fabry disease (n = 51). 54% were on ERT (n = 44), of whom 70% (n = 31) were on intravenous enzyme replacement therapies and 30% (n = 13) were on oral chaperone therapy. The SOV dimensions ranged from 24 to 43 mm (mean 32 ± 4.4 mm). Aortic root dilatation was identified in 8.5% of the patient group (n = 7). Ascending aortic dimensions beyond the root were available in 72 patients. 2 patients had ascending diameters >40mm, but both also had aortic root dilatation. Table 1 outlines the prevalence of aortic root dilatation in our cohort grouped by gender, history of hypertension, cardiac involvement and use of ERT. The prevalence of aortic root dilatation in patients with cardiac involvement from their Fabry disease was significantly greater compared to patients with no cardiac involvement (p= 0.03). The prevalence of aortic root dilatation was not statistically different when grouped by gender, history of hypertension or use of ERT. Conclusion Fabry disease is a recognised lysosomal storage disorder associated with aortic root dilatation, although the exact mechanism remains incompletely understood. The prevalence of aortic root dilatation in our cohort was lower than previously reported. This may reflect advancements in treatment strategies and varying criteria used to define dilatation in previous studies. In our patient cohort the degree of aortic dilatation was mild, not reaching surgical requirement, and was not related to a history of hypertension. Although numbers were small, a higher prevalence was seen in patients with myocardial involvement by their Fabry disease, suggesting a possible link between the cardiac Fabry process and changes in the aortic wall. Conflict of Interest none

Summary Background Pompe disease is a rare, progressive neuromuscular disorder caused by deficiency of acid α-glucosidase (GAA) and accumulation of lysosomal glycogen. We assessed the safety and efficacy of avalglucosidase alfa, a recombinant human GAA enzyme replacement therapy specifically designed for enhanced mannose-6-phosphate-receptor targeting and enzyme uptake aimed at increased glycogen clearance, compared with the current approved standard of care, alglucosidase alfa, in patients with late-onset Pompe disease. Methods We did a randomised, double-blind, phase 3 trial at 55 sites in 20 countries. We enrolled individuals (aged ≥3 years) with enzymatically confirmed late-onset Pompe disease who had never received treatment. We used a centralised treatment allocation system to randomly allocate participants to either avalglucosidase alfa or alglucosidase alfa. Participants and investigators were unaware of their treatment allocation. The primary outcome measure was change from baseline to week 49 in upright forced vital capacity percent (FVC%) predicted. We used a hierarchical fixed sequential testing strategy, whereby non-inferiority of avalglucosidase alfa compared with alglucosidase alfa was assessed first, with a non-inferiority margin of 1·1. If non-inferiority was seen, then superiority was tested with a 5% significance level. The key secondary objective was effect on functional endurance, measured by the 6-minute walk test (6MWT). Safety was assessed, including treatment-emergent adverse events and infusion-associated reactions. The modified intent-to-treat population was the primary analysis population for all efficacy analyses. The safety population was the analysis population for safety analyses. This trial is registered with ClinicalTrials.gov , NCT02782741 . We report results of the 49-week primary analysis period. Findings Between Nov 2, 2016, and March 29, 2019, 100 participants were randomly allocated avalglucosidase alfa (n=51) or alglucosidase alfa (n=49). Treatment with avalglucosidase alfa resulted in a least-squares mean improvement in upright FVC% predicted of 2·89% (SE 0·88) compared with 0·46% (0·93) with alglucosidase alfa at week 49 (difference 2·43% [95% CI −0·13 to 4·99]). Non-inferiority was shown because the lower bound of the 95% CI for the difference far exceeded the predefined non-inferiority margin but did not exclude 0 (p=0·0074). Superiority was not reached (p=0·063), so formal testing was stopped, as per the testing hierarchy. Improvements were also seen in the 6MWT with avalglucosidase alfa compared with alglucosidase alfa, with greater increases in distance covered (difference 30·01 m [95% CI 1·33 to 58·69]) and percent predicted (4·71% [0·25 to 9·17]). Treatment-emergent adverse events potentially related to treatment were reported in 23 (45%) of 51 participants in the avalglucosidase alfa group and in 24 (49%) of 49 in the alglucosidase alfa group, and infusion-associated reactions were reported in 13 (26%) participants in the avalglucosidase alfa group and 16 (33%) in the alglucosidase alfa group. Of the five trial withdrawals, all in the alglucosidase alfa group, four were due to adverse events, including two infusion-associated reactions. Serious treatment-emergent adverse events were reported in eight (16%) participants who received avalglucosidase alfa and in 12 (25%) who received alglucosidase alfa. One participant treated with alglucosidase alfa died because of acute myocardial infarction determined to be unrelated to treatment. Antidrug antibody responses were similar in both groups. High and persistent titres (≥12 800) and neutralising antibodies were more common with alglucosidase alfa (in 16 [33%] participants) than with avalglucosidase alfa (ten [20%]). Interpretation We consider that this study provides evidence of clinically meaningful improvement with avalglucosidase alfa therapy over alglucosidase alfa in respiratory function, ambulation, and functional endurance, with no new safety signals reported. An open-label extended-treatment period is ongoing to confirm the long-term safety and efficacy of avalglucosidase alfa, with the aim for this therapy to become the new standard treatment in late-onset Pompe disease. Funding Sanofi Genzyme.

The Erlenmeyer flask deformity is a common skeletal modeling deformity, but current classification systems are binary and may restrict its utility as a predictor of associated skeletal conditions. A quantifiable 3-point system of severity classification could improve its predictive potential in disease. Ratios were derived from volumes of regions of interests drawn in 50 Gaucher’s disease patients. ROIs were drawn from the distal physis to 2 cm proximal, 2 cm to 4 cm, and 4 cm to 6 cm. Width was also measured at each of these boundaries. Two readers rated these 100 femurs using a 3-point scale of severity classification. Weighted kappa indicated reliability and one-way analysis of variance characterized ratio differences across the severity scale. Accuracy analyses allowed determination of clinical cutoffs for each ratio. Pearson’s correlations assessed the associations of volume and width with a shape-based concavity metric of the femur. The volume ratio incorporating the metaphyseal region from 0 to 2 cm and the diametaphyseal region at 4–6 cm was most accurate at distinguishing femurs on the 3-point scale. Receiver operating characteristic curves for this ratio indicated areas of 0.95 to distinguish normal and mild femurs and 0.93 to distinguish mild and severe femurs. Volume was moderately associated with the degree of femur concavity. The proposed volume ratio method is an objective, proficient method at distinguishing severities of the Erlenmeyer flask deformity with the potential for automation. This may have application across diseases associated with the deformity and deficient osteoclast-mediated modeling of growing bone. Electronic supplementary material The online version of this article (10.1007/s00256-020-03561-2) contains supplementary material, which is available to authorized users.

Background and Aims Fabry disease (FD) is a rare, X-linked, genetic disorder caused by pathogenic variants in the gene for the lysosomal enzyme alpha-galactosidase A (αGal-A). The progressive accumulation of glycosphingolipids, most notably globotriaosylceramide (GL-3), leads to renal, cardiovascular, and other clinical manifestations over decades. In a single-arm phase 2 study, glucosylceramide synthase inhibition with venglustat led to a reduction in lysosomal GL-3 inclusions in skin capillary endothelial cells, as well as a progressive reduction in plasma GL-3 to normal levels by 26 weeks, with a continued decrease to low-normal levels after 3 years of therapy. We used patient data from a previously completed placebo-controlled phase 3 study of agalsidase beta (Fabrazyme) as historical control to compare the effect of venglustat treatment with placebo over 6 months and with agalsidase beta over 3 years. Methods In the venglustat phase 2 study, previously untreated classic FD patients were treated with daily venglustat for up to 3 years (NCT02228460, NCT02489344). For comparison to placebo, change in plasma GL-3 levels after 26 weeks of venglustat treatment was compared with matched historical control data from previously untreated classic FD patients who were treated for 20 weeks with placebo in the phase 3 agalsidase beta study (Eng et al, N Engl J Med 345:9, 2001). For comparison to agalsidase beta, the historical control arm was matched patients treated with agalsidase beta in the phase 3 study; change in plasma GL-3 was compared at multiple time points up to 3 years. Entry criteria and baseline characteristics were similar between the two studies. Due to the much larger numbers of patients in the phase 3 agalsidase beta study, venglustat patients were matched 1:X (variable match) with control (placebo or agalsidase beta) patients based on propensity scores using baseline variables of age, plasma GL-3, gender, UPCR (< 500 vs 500-1000 vs >1000 mg/g), and eGFR (= 80 mL/min/1.73m2) as matching variables. Plasma GL-3 was measured at Sanofi Genzyme by LC/MS/MS, using the same method for the two studies, with controls in place to assure assay consistency. Results Venglustat patients (N=11) were matched to 19 patients for the placebo comparison and to 28 patients for comparison to Fabrazyme. All patients in all 3 groups were male and had elevated plasma GL-3, UPCR Conclusions Glucosylceramide synthase inhibition with venglustat led to a significantly greater reduction in plasma GL-3 compared to placebo after 6 months, and treatment for 2-3 years led to a significantly greater reduction in plasma GL-3 compared with agalsidase beta. These results highlight the potential of long-term treatment venglustat to reverse the accumulation of GL-3 in classic FD.

Background and Aims Fabry disease (FD) is a rare, X-linked, genetic disorder caused by mutations in the gene for the lysosomal enzyme alpha-galactosidase A (αGal-A). The progressive accumulation of glycosphingolipids, most notably globotriaosylceramide (GL-3), in lysosomes of a variety of organs and cell types leads, over decades, to renal, cardiovascular, and other clinical manifestations. In a phase 2 study, glucosylceramide synthase inhibition with venglustat led to a progressive reduction in plasma GL-3 to low-normal levels. Scoring by light microscopy showed a reduction in lysosomal GL-3 inclusions in skin capillary endothelial cells (EC) after 3 years of therapy, although not after 6 months. To further characterize the effect of venglustat using more precise methods, we applied unbiased stereological methods to quantitate GL-3 inclusions in skin ECs. Methods Skin biopsies were obtained from classic male Fabry disease patients (N = 11) at baseline and during daily treatment with venglustat in a phase 2 study (NCT02228460, NCT02489344). Images from at least 50 superficial skin capillaries were obtained using transmission electron microscopy at 7,500 X magnification. The fraction of the volume (Vv) of cytoplasm occupied by GL-3 inclusions [Vv(Inc/Endo)] in all ECs in these capillaries was estimated using point counting by a masked reader. Two-sided paired t tests were used to evaluate differences between baseline and post-treatment values at each time point. Results Venglustat therapy led to a significant reduction from baseline in Vv(Inc/Endo) of 21.1% after 6 months and 38.7% after 3 years of treatment (Figure). Conclusions Treatment with venglustat led to a reduction in GL-3 inclusion fractional volume in skin capillary ECs which was detectable after 6 months using precise quantitative methods. This was followed by further reduction over the next 2 1/2 years. We posit that, in the absence of αGal-A activity, inhibition of GL-3 production with venglustat allowed other enzymatic or non-enzymatic mechanisms to progressively reduce EC lysosomal GL-3 content, and that long-term venglustat therapy may therefore prevent or reverse progressive tissue injury in Fabry disease.

Background The European Medicine Agency granted marketing approval to 164 orphan medicinal products for rare diseases, among which 28 products intended for the treatment of hereditary metabolic diseases. Taking advantage of its privileged connection with 69 healthcare centres of excellence in this field, MetabERN, the European Reference Network for hereditary metabolic diseases, performed a survey asking health care providers from 18 European countries whether these products are available on the market, reimbursed and therefore accessible for prescription, and actually delivered in their centre. Results Responses received from 52 centres (75%) concerned the design of treatment plans, the access to marketed products, and the barriers to delivery. Treatment options are always discussed with patients, who are often involved in their treatment plan. Most products (26/28) are available in most countries (15/18). Among the 15 broadly accessible products (88.5% of the centres), 9 are delivered to most patients (mean 70.1%), and the others to only few (16.5%). Among the 10 less accessible products (40.2% of the centres), 6 are delivered to many patients (66.7%), and 4 are rarely used (6.3%). Information was missing for 3 products. Delay between prescription and delivery is on average one month. Beside the lack of availability or accessibility, the most frequent reasons for not prescribing a treatment are patients’ clinical status, characteristic, and personal choice. Conclusions Data collected from health care providers in the MetabERN network indicate that two-third of the orphan medicines approved by EMA for the treatment of hereditary metabolic diseases are accessible to treating patients, although often less than one-half of the patients with the relevant conditions actually received the approved product to treat their disease. Thus, in spite of the remarkable achievement of many products, patients concerned by EMA-approved orphan medicinal products have persistent unmet needs, which deserve consideration. The enormous investments made by the companies to develop products, and the high financial burden for the Member States to purchase these products emphasize the importance of a scrupulous appreciation of treatment value involving all stakeholders at early stage of development, before marketing authorization, and during follow up.

Objectives The PRoposing Early Disease Indicators for Clinical Tracking in Fabry Disease (PREDICT-FD) initiative aimed to reach consensus among a panel of global experts on early indicators of disease progression that may justify FD-specific treatment initiation. Design and setting Anonymous feedback from panellists via online questionnaires was analysed using a modified Delphi consensus technique. Questionnaires and data were managed by an independent administrator directed by two non-voting cochairs. First, possible early indicators of renal, cardiac and central/peripheral nervous system (CNS/PNS) damage, and other disease and patient-reported indicators assessable in routine clinical practice were compiled by the cochairs and administrator from panellists’ free-text responses. Second, the panel scored indicators for importance (5-point scale: 1=not important; 5=extremely important); indicators scoring ≥3 among >75% of panellists were then rated for agreement (5-point scale: 1=strongly disagree; 5=strongly agree). Indicators awarded an agreement score ≥4 by >67% of panellists achieved consensus. Finally, any panel-proposed refinements to consensus indicator definitions were adopted if >75% of panellists agreed. Results A panel of 21 expert clinicians from 15 countries provided information from which 83 possible current indicators of damage (kidney, 15; cardiac, 15; CNS/PNS, 13; other, 16; patient reported, 24) were compiled. Of 45 indicators meeting the importance criteria, consensus was reached for 29 and consolidated as 27 indicators (kidney, 6; cardiac, 10; CNS/PNS, 2; other, 6; patient reported, 3) including: (kidney) elevated albumin:creatinine ratio, histological damage, microalbuminuria; (cardiac) markers of early systolic/diastolic dysfunction, elevated serum cardiac troponin; (CNS/PNS) neuropathic pain, gastrointestinal symptoms suggestive of gastrointestinal neuropathy; (other) pain in extremities/neuropathy, angiokeratoma; (patient-reported) febrile crises, progression of symptoms/signs. Panellists revised and approved proposed chronologies of when the consensus indicators manifest. The panel response rate was >95% at all stages. Conclusions PREDICT-FD captured global opinion regarding current clinical indicators that could prompt FD-specific treatment initiation earlier than is currently practised., Instituto de Estudios Inmunológicos y Fisiopatológicos

We report the cognitive features and progression of Parkinson's disease (PD) in five patients with concurrent Gaucher disease. The patients presented at an earlier age than patients with sporadic PD, as previously noted by others; but in contrast to many previous reports, our patients followed a variable clinical course. While two patients developed early cognitive deficits and dementia, three others remained cognitively intact over the follow-up period. Thus, in this small case series, PD in the context of GD more closely resembles idiopathic PD in terms of its clinical heterogeneity in contrast to PD associated with GBA heterozygote mutations.

The Gaucher Outcome Survey (GOS) is an international disease-specific registry established in 2010 for patients with a confirmed diagnosis of Gaucher disease (GD), regardless of GD type or treatment status. Historically, there has been a limited understanding of type 3 GD (GD3) and its natural history in patients irrespective of their treatment status. Here, we describe the disease characteristics of patients with GD3 enrolled in GOS. As of October 2015, 1002 patients had been enrolled, 26 of whom were reported as GD3. The majority of patients with GD3 were from the US (13; 50.0%), seven (26.9%) were from the UK, three (11.5%) from Israel, and three (11.5%) from Brazil. No patients were of Ashkenazi Jewish origin. Median age of symptom onset was 1.4 (interquartile range: 0.5–2.0) years. The most common GBA1 mutation genotype was L444P/L444P, occurring in 16 (69.6%) of 23 patients who had genotyping information available. Nine patients reported a family history of GD (any type). Of 21 patients with treatment status information, 20 (95.2%) had received GD-specific treatment at any time, primarily imiglucerase (14 patients) and/or velaglucerase alfa (13 patients). Hemoglobin concentrations and platelet counts at GOS entry were within normal ranges for most patients, and there were no reports of severe hepatomegaly or of splenomegaly in non-splenectomized patients, most likely indicative of the effects of treatment received prior to GOS entry. This analysis provides information on the characteristics of patients with GD3 that could be used as the baseline for longitudinal follow-up of these patients.

The Gaucher Outcome Survey (GOS) is an international Gaucher disease (GD) registry established in 2010 for patients with a confirmed GD diagnosis, regardless of GD type or treatment status, designed to evaluate the safety and long‐term effectiveness of velaglucerase alfa and other GD‐related treatments. As of February 25, 2017, 1209 patients had enrolled, the majority from Israel (44.3%) and the US (31.4%). Median age at GOS entry was 40.4 years, 44.1% were male, and 13.3% had undergone a total splenectomy. Most patients had type 1 GD (91.5%) and were of Ashkenazi Jewish ethnicity (55.8%). N370S/N370S was the most prevalent genotype, accounting for 44.2% of genotype‐confirmed individuals (n = 847); however, there was considerable variation between countries. A total of 887 (73.4%) patients had received ≥1 GD‐specific treatment at any time, most commonly imiglucerase (n = 587), velaglucerase alfa (n = 507), and alglucerase (n = 102). Hematological and visceral findings at the time of GOS entry were close to normal for most patients, probably a result of previous treatment; however, spleen volume of patients in Israel was almost double that of patients elsewhere (7.2 multiples of normal [MN] vs. 2.7, 2.9 and 4.9 MN in the US, UK and rest of world), which may be explained by a greater disease severity in this cohort. This analysis aimed to provide an overview of GOS and present baseline demographic and disease characteristics of participating patients to help improve the understanding of the natural history of GD and inform the overall management of patients with the disease.

Gaucher disease (GD) is a rare hereditary disorder caused by a deficiency of the lysosomal enzyme β-glucocerebrosidase. Diagnosis is challenging owing to a wide variability in clinical manifestations and severity of symptoms. Many patients may experience marked delays in obtaining a definitive diagnosis. The two surveys reported herein aimed to explore the patient journey to diagnosis of GD from the perspectives of Gaucher expert physicians and patients. Findings from the surveys revealed that many patients experienced diagnostic delays and misdiagnoses, with nearly 1 in 6 patients stating that they were not diagnosed with GD for 7years or more after first consulting a doctor. Physicians and patients both reported multiple referrals to different specialties before a diagnosis of GD was obtained, with primary care, haematology/haematology-oncology and paediatrics the main specialties to which patients first presented. Splenomegaly, thrombocytopenia, anaemia and bone pain were reported as the most common medical problems at first presentation in both surveys. These findings support a clear need for straightforward and easy-to-follow guidance designed to assist non-specialists to identify earlier patients who are at risk of GD.

Mutations in more than 250 genes are implicated in inherited retinal dystrophy; the encoded proteins are involved in a broad spectrum of pathways. The presence of unsolved families after highly parallel sequencing strategies suggests that further genes remain to be identified. Whole-exome and -genome sequencing studies employed here in large cohorts of affected individuals revealed biallelic mutations in ARHGEF18 in three such individuals. ARHGEF18 encodes ARHGEF18, a guanine nucleotide exchange factor that activates RHOA, a small GTPase protein that is a key component of tight junctions and adherens junctions. This biological pathway is known to be important for retinal development and function, as mutation of CRB1, encoding another component, causes retinal dystrophy. The retinal structure in individuals with ARHGEF18 mutations resembled that seen in subjects with CRB1 mutations. Five mutations were found on six alleles in the three individuals: c.808A>G (p.Thr270Ala), c.1617+5G>A (p.Asp540Glyfs ∗ 63), c.1996C>T (p.Arg666 ∗ ), c.2632G>T (p.Glu878 ∗ ), and c.2738_2761del (p.Arg913_Glu920del). Functional tests suggest that each disease genotype might retain some ARHGEF18 activity, such that the phenotype described here is not the consequence of nullizygosity. In particular, the p.Thr270Ala missense variant affects a highly conserved residue in the DBL homology domain, which is required for the interaction and activation of RHOA. Previously, knock-out of Arhgef18 in the medaka fish has been shown to cause larval lethality which is preceded by retinal defects that resemble those seen in zebrafish Crumbs complex knock-outs. The findings described here emphasize the peculiar sensitivity of the retina to perturbations of this pathway, which is highlighted as a target for potential therapeutic strategies.

Inherited retinal disease is a common cause of visual impairment and represents a highly heterogeneous group of conditions. Here, we present findings from a cohort of 722 individuals with inherited retinal disease, who have had whole-genome sequencing (n = 605), whole-exome sequencing (n = 72), or both (n = 45) performed, as part of the NIHR-BioResource Rare Diseases research study. We identified pathogenic variants (single-nucleotide variants, indels, or structural variants) for 404/722 (56%) individuals. Whole-genome sequencing gives unprecedented power to detect three categories of pathogenic variants in particular: structural variants, variants in GC-rich regions, which have significantly improved coverage compared to whole-exome sequencing, and variants in non-coding regulatory regions. In addition to previously reported pathogenic regulatory variants, we have identified a previously unreported pathogenic intronic variant in $\textit{CHM}$ in two males with choroideremia. We have also identified 19 genes not previously known to be associated with inherited retinal disease, which harbor biallelic predicted protein-truncating variants in unsolved cases. Whole-genome sequencing is an increasingly important comprehensive method with which to investigate the genetic causes of inherited retinal disease.

Background Fabry disease (FD) is a genetic disorder caused by a deficiency in the enzyme alpha-galactosidase A, leading to an accumulation of glycosphingolipids in tissues across the body. Cardiac disease is the leading cause of morbidity and mortality. Advanced disease, characterised by extensive left ventricular hypertrophy, ventricular dysfunction and fibrosis, is known to be associated with an increase in arrhythmia. Data identifying risk factors for arrhythmia are limited, and no Fabry-specific risk stratification tool is available to select those who may benefit from initiation of medical or device therapy (implantable cardiac defibrillators). Current monitoring strategies have a limited diagnostic yield, and implantable loop recorders (ILRs) have the potential to change treatment and clinical outcomes. Aim The aim of this study is to determine whether ILRs can (1) improve arrhythmia detection in FD and (2) identify risk predictors of arrhythmia. Methods A prospective, 5-year, open-label, international, multi-centre randomised controlled trial of a minimum of 164 participants with genetically or enzymatically confirmed FD (or both) who have evidence of cardiac disease will be recruited from five centres: Queen Elizabeth Hospital, Birmingham, UK; Salford Royal Hospital, Salford, UK; Royal Free Hospital, London, UK; Addenbrookes Hospital, Cambridge, UK; and Westmead Hospital, Sydney, Australia. Participants will be block-randomised (1:1) to two study arms for cardiac monitoring (i) control arm: standard of care with annual 24 h or 5-day Holter monitor or (ii) treatment arm: continuous cardiac monitoring with ILR implantation plus standard of care. Participants will undergo multiple investigations—blood/urine biomarkers, 12-lead and advanced electrocardiogram (ECG) recording, echocardiography and cardiovascular magnetic resonance (CMR) imaging—at baseline and 6–12 monthly follow-up visits. The primary endpoint is identification of arrhythmia requiring initiation or alteration in therapy. Secondary outcome measures include characterising the risk factors associated with arrhythmia and outcome data in the form of imaging, ECG and blood biomarkers. Discussion This is the first study evaluating arrhythmia burden and the use of ILR across the spectrum of risk profiles in Fabry cardiomyopathy. This will enable detailed characterisation of arrhythmic risk predictors in FD and ultimately support formulation of Fabry-specific guidance in this high-risk population. Trial registration ClinicalTrials.gov (NCT03305250). Registered on 9 October 2017. Electronic supplementary material The online version of this article (10.1186/s13063-019-3425-1) contains supplementary material, which is available to authorized users.

Fabry disease is a treatable X-linked condition leading to progressive cardiomyopathy, arrhythmia and premature death. Atrial and ventricular arrhythmias contribute significantly to adverse prognosis; however, guidance to determine which patients require cardiovascular implantable electronic devices (CIEDs) is sparse. We aimed to evaluate indications for implantation practice in the UK and quantify device utilisation.In this retrospective study, we included demographic, clinical and imaging data from patients in four of the largest UK Fabry centres. Ninety patients with Fabry disease were identified with CIEDs implanted between June 2001 and February 2018 (FD-CIED group). To investigate differences in clinical and imaging markers between those with and without devices, these patients were compared with 276 patients without a CIED (FD-control).In the FD-CIED group, 92% of patients with permanent pacemakers but only 28% with implantable cardioverter-defibrillators had a class 1 indication for implantation. A further 44% of patients had defibrillators inserted for primary prevention outside of current guidance. The burden of arrhythmia requiring treatment in the FD-CIED group was high (asymptomatic atrial fibrillation:29%; non-sustained ventricular tachycardia requiring medical therapy alone: 26%; sustained ventricular tachycardia needing anti-tachycardia pacing/defibrillation: 28%). Those with devices were older, had greater LV mass, more scar tissue and larger atrial size.Arrhythmias are common in Fabry patients. Those with cardiac devices had high rates of atrial fibrillation requiring anticoagulation and ventricular arrhythmia needing device treatment. These are as high as those in hypertrophic cardiomyopathy, supporting the need for Fabry-specific indications for device implantation.

Background Fabry disease is an X-linked lysosomal storage disorder caused by GLA mutations, resulting in α-galactosidase (α-Gal) deficiency and accumulation of lysosomal substrates. Migalastat, an oral pharmacological chaperone being developed as an alternative to intravenous enzyme replacement therapy (ERT), stabilises specific mutant ( amenable ) forms of α-Gal to facilitate normal lysosomal trafficking. Methods The main objective of the 18-month, randomised, active-controlled ATTRACT study was to assess the effects of migalastat on renal function in patients with Fabry disease previously treated with ERT. Effects on heart, disease substrate, patient-reported outcomes (PROs) and safety were also assessed. Results Fifty-seven adults (56% female) receiving ERT (88% had multiorgan disease) were randomised (1.5:1), based on a preliminary cell-based assay of responsiveness to migalastat, to receive 18 months open-label migalastat or remain on ERT. Four patients had non-amenable mutant forms of α-Gal based on the validated cell-based assay conducted after treatment initiation and were excluded from primary efficacy analyses only. Migalastat and ERT had similar effects on renal function. Left ventricular mass index decreased significantly with migalastat treatment (−6.6 g/m 2 (−11.0 to −2.2)); there was no significant change with ERT. Predefined renal, cardiac or cerebrovascular events occurred in 29% and 44% of patients in the migalastat and ERT groups, respectively. Plasma globotriaosylsphingosine remained low and stable following the switch from ERT to migalastat. PROs were comparable between groups. Migalastat was generally safe and well tolerated. Conclusions Migalastat offers promise as a first-in-class oral monotherapy alternative treatment to intravenous ERT for patients with Fabry disease and amenable mutations. Trial registration number: NCT00925301; Pre-results.

© 2019 American Society of Human Genetics The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.

This chapter discusses six diseases caused by inborn errors of metabolism affecting the biosynthesis of haem. Haem is a tetracyclic metal-binding compound involved in oxygen transport (in haemoglobin and myoglobin) and redox reactions (e.g. in the cytochrome P450 system). Each of these conditions is caused by a single gene defect in one of the enzymes involved in the biosynthesis of haem. Inheritance is usually autosomal dominant with incomplete penetrance. The enzyme defect results in disease, not as a result of deficiency of the reaction product, but as a result of accumulation of precursors. Early, soluble precursors, 5-aminolaevulinic acid, and porphobilinogen (not porphyrins as such) are neurotoxic and, when present in great excess, as occurs when flux through the haem synthetic pathway is increased in response to particular medications or hormones, lead to acute neurovisceral crises. Later cyclical precursors (porphyrins) in the pathway are also water soluble and excreted in urine, but are susceptible to activation by electromagnetic radiation in the visible spectrum and are converted to free-radical metabolites that cause pain, inflammation, and tissue damage in the skin. The final haem precursors (also porphyrins) are hydrophobic and excreted in the bile and faeces and are also activated by light to toxic metabolites.

Next-generation sequencing has been invaluable in the elucidation of the genetic etiology of many subtypes of intellectual disability in recent years. Here, using exome sequencing and whole-genome sequencing, we identified three de novo truncating mutations in WAS protein family member 1 (WASF1) in five unrelated individuals with moderate to profound intellectual disability with autistic features and seizures. WASF1, also known as WAVE1, is part of the WAVE complex and acts as a mediator between Rac-GTPase and actin to induce actin polymerization. The three mutations connected by Matchmaker Exchange were c.1516C>T (p.Arg506Ter), which occurs in three unrelated individuals, c.1558C>T (p.Gln520Ter), and c.1482delinsGCCAGG (p.Ile494MetfsTer23). All three variants are predicted to partially or fully disrupt the C-terminal actin-binding WCA domain. Functional studies using fibroblast cells from two affected individuals with the c.1516C>T mutation showed a truncated WASF1 and a defect in actin remodeling. This study provides evidence that de novo heterozygous mutations in WASF1 cause a rare form of intellectual disability. ispartof: AMERICAN JOURNAL OF HUMAN GENETICS vol:103 issue:1 pages:144-153 ispartof: location:United States status: published

Objective To estimate clinical progression and resource utilisation together with the associated costs of managing children and adults with LAL Deficiency, at a tertiary referral centre in the UK. Methods A retrospective chart review was undertaken of patients in the UK with a confirmed diagnosis of LAL Deficiency who were managed at a LAL Deficiency tertiary referral treatment centre. Patients’ pathways, treatment patterns, health outcomes and resource use were quantified over differing lengths of time for each patient enabling the NHS cost of patient management in tertiary care to be estimated. Results The study population comprised 19 patients of whom 58% were male. Mean age at the time of initial presentation was 15.5 years and the mean age at diagnosis was 18.0 years. 63%, 53% and 42% of patients had hepatomegaly, abnormal lipid storage and splenomegaly at a mean age of presentation of 17.8, 17.1 and 20.9 years, respectively. Over a period of 50 years there were a mean of 48.5 clinician visits and 3.4 hospital admissions per patient. The mean NHS cost of patient management at a LAL Deficiency tertiary referral treatment centre, spanning a period of over 50 years was £61,454 per patient. Conclusion This study provides important insights into a number of aspects of the disease that are difficult to ascertain from published case reports. Additionally, it provides the best estimate available of NHS resource use and costs with which to inform policy and budgetary decisions pertaining to managing this ultra-orphan disease.

Background Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by deficiency in acid beta-glucosidase. GD exhibits a wide clinical spectrum of disease severity with an unpredictable natural course. Plasma chitotriosidase activity and CC chemokine ligand 18 (CCL18) have been exchangeably used for monitoring GD activity and response to enzyme replacement therapy in conjunction with clinical assessment. Yet, a large-scale head-to-head comparison of these two biomarkers is currently lacking. We propose a collaborative systematic review with meta-analysis of individual participant data (IPD) to compare the accuracy of plasma chitotriosidase activity and CCL18 in assessing type I (i.e., non-neuropathic) GD severity. Methods Eligible studies include cross-sectional, cohort, and randomized controlled studies recording both plasma chitotriosidase activity and CCL18 level at baseline and/or at follow-up in consecutive children or adult patients with type I GD. Pre-specified surrogate outcomes reflecting GD activity include liver and spleen volume, hemoglobin concentration, platelet count, and symptomatic bone events with imaging confirmation. Primary studies will be identified by searching Medline (1995 onwards), EMBASE (1995 onwards), and Cochrane Central Register of Controlled Trials (CENTRAL). Electronic search will be complemented by contacting research groups in order to identify unpublished relevant studies. Where possible, IPD will be extracted from published articles. Corresponding authors will be invited to collaborate by supplying IPD. The methodological quality of retrieved studies will be appraised for each study outcome, using a checklist adapted from the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The primary outcome will be a composite of liver volume >1.25 multiple of normal (MN), spleen volume >5 MN, hemoglobin concentration

Open Mustard Seed (OMS) is a project of the Institute for Data-Driven Design (ID3) and the M.I.T. Media Lab that seeks to develop new social ecosystems consisting of trusted self-healing digital institutions operating on open networks. The cornerstone of OMS is an open data platform that enables people to share all their personal data within a legally constituted "trust framework". This framework allows people to initiate their own "personal data store" (PDS) that can securely store and process static and dynamic data about themselves. All elements of the trust framework - open authentication, storage, discovery, payment, auditing, market making, and monetized "app store" services - are based on "privacy by design" principles. That is, privacy, security, and trusted exchange are built into the very design of the system itself.

Gaucher disease (GD) is a rare, autosomal recessive condition, characterized by hepatosplenomegaly, thrombocytopenia and anemia. Velaglucerase alfa resulted in improvements in these parameters in clinical studies, but there are limited data on long-term efficacy and safety in real-life clinical practice. The Gaucher Outcome Survey (GOS), an international registry for patients with confirmed GD regardless of type or treatment status, collects data during patients’ routine care, and provides an opportunity for long-term analysis of patients receiving velaglucerase alfa. This evaluation included 197 treatment naive patients who initiated velaglucerase alfa upon enrollment into GOS and continued velaglucerase alfa treatment for up to 8 years (mean 59.8 months). Hemoglobin levels, platelet counts, liver and spleen volume, and chitotriosidase levels were assessed. At baseline (start of velaglucerase alfa), 77.2% patients were aged ≥18 years, 58.9% were female, 52.8% had a known N370S-containing genotype, and 87.8% had an intact spleen (including partial splenectomy). Patients showed stabilization or improvement in all measured clinical parameters during the study period. After 4 years of velaglucerase alfa treatment, mean (SD) hemoglobin levels increased by 7.5 g/L from baseline to 136.4 (12.8) g/L (n=19 patients with available data) and mean (SD) platelet counts increased by 54.6 x109/L to 166.4 (57.9) x109/L (n=19). Liver size remained stable at 1.2 MN (n=4) over 4 years, while spleen size decreased from 7.5 MN to 6.4 MN (n=4), a mean reduction of 1.2 MN. Mean (SD) chitotriosidase values reduced by 4302.7 nmol/mL/h to 1019.1 (1907.45) nmol/mL/h at year 4 (n=14). Sixty-one (31.0%) patients experienced 153 adverse events during velaglucerase alfa treatment 16 AEs in 10 patients were considered related to velaglucerase, but none were serious. This analysis suggests that improvements in clinical parameters achieved with velaglucerase alfa can be maintained long-term in real-life clinical practice. This study and writing support were funded by Shire.

Pegunigalsidase alfa, a novel α-galactosidase-A enzyme for the treatment of Fabry disease (FD) is a stable, homo-dimeric PEGylated protein, previously demonstrated (Hughes et al, LDN-2016) to have substantially improved pharmacokinetics (PK) parameters compared to the two currently available enzyme replacement therapies (ERTs). The ongoing phase 3 trial “BRIGHT” (PB-102-F50, NCT03180840) is an open-label switch-over study assessing safety, PK, and efficacy of pegunigalsidase alfa (2 mg/kg) given every 4 weeks for 52 weeks to FD patients previously treated with either agalsidase alfa or agalsidase beta. Aim of the study: to explore a more convenient dosing regimen exploiting the improved PK characteristics of pegunigalsidase alfa, as shown by PK modelling from the Phase 1-2 study results (Warnock et al, LDN-2017). The trial will enroll up to 30 patients without severe clinical symptoms and relatively slow disease progression, as evaluated by the investigator. Pegunigalsidase alfa plasma levels are measured at multiple time points before, during, and up to 28±3 days post-infusion for PK evaluation. Preliminary PK results, from the first 15 patients, show a half-life of ~80 hours and persistent plasma levels over the entire 4-week dosing interval, with a mean concentration on day 28 post-infusion of 138 ± 42 ng/mL. The Area Under the Curve (AUC) of day 0-28 was found to be 2,126,091 ng*h/mL, of which the mean partial AUC during the 4th week was ~30,000 ng*h/mL confirming the study assumption. The AUC of day 0-28 is significantly greater than agalsidase beta (AUC0-∞

Anecdotal reports suggest that the currently approved dosing interval of agalsidase alfa (0.2 mg/kg/2 weeks) for Fabry disease treatment is too long. This randomised, double-blind, placebo-controlled, crossover study investigated three altered dosing intervals. 18 Fabry patients received three agalsidase alfa dosing schedules, each for four weeks (A: 0.2 mg/kg∗2 weeks, B: 0.1 mg/kg/week, C: 0.2 mg/kg/week). Health state, pain levels, sweat volume and latency and plasma and urinary globotriaosylceramide levels were recorded throughout the study. No significant differences were found among the schedules for the primary efficacy outcome of self-assessed health state, or for pain scores. A trend toward increased sweat volume on QSART testing, and reduced urine globotriaosylceramide concentration were seen with treatment schedule C. Agalsidase alfa was safe and well tolerated with all schedules. In conclusion, the primary analyses did not find weekly infusions of agalsidase alfa to be statistically better than the approved dosing schedule however the data indicates that further studies with more patients over a longer period are required to more accurately determine the optimum dose and schedule.