Enzyme replacement therapy with agalsidase alfa in children with Fabry disease

AIM: To assess the effects of enzyme replacement therapy (ERT) in children with Fabry disease. METHODS: Safety and efficacy of ERT with agalsidase alfa, 0.2 mg/kg infused over 40 minutes every 2 weeks for 23 weeks, were studied in a multicentre open-label trial in nine boys and four girls. Median age at the start of the study was 11.0 years (range 3.5-18 years). RESULTS: Fifty-four adverse events were reported in 11 patients. No serious adverse events related to ERT were reported. Twelve of the 54 adverse events were considered possibly or probably related to ERT. Infusion reactions (8 mild, 3 moderate) occurred in four boys, in seven infusions. One boy developed IgG antibodies, although he continued to make good clinical progress. At the end of the study, two of the four boys and the one girl on regular pain medication at baseline had stopped taking analgesics. Brief Pain Inventory (BPI) scores decreased in most patients by week 12 and were sustained until the end of the study. This change was greater in the boys, who had higher (worse) BPI scores at baseline. Pain-related quality of life (QoL) scores also decreased during the study. Plasma globotriaosylceramide concentrations and urinary globotriaosylceramide:sphingomyelin ratios decreased after 12 and 23 weeks of therapy, particularly in the boys. Increases in sweat volume were recorded in three out of five of the boys and in one of two girls tested after 23 weeks of treatment. CONCLUSION: ERT with agalsidase alfa in children with Fabry disease is well tolerated and, in the short term, appears to decrease pain and to improve pain-related QoL.     

Hearing improvement in patients with Fabry disease treated with agalsidase alfa

AIM: To describe the nature and prevalence of hearing loss in Fabry disease, and its response to enzyme replacement therapy (ERT) with agalsidase alfa. METHODS: Fifteen male patients with Fabry disease were enrolled in a randomized, double-blind study and received placebo (n = 8) or ERT (n = 7) with agalsidase alfa for 6 months. This was followed by an open-label extension of 36 months thus far. Alongside this trial, an additional eight men and two women have so far received open-label ERT for between 6 and 30 months. Pure-tone audiometry, impedance audiometry and otoacoustic emission testing were performed at 0 (baseline), 6, 18, 30 and 42 months. RESULTS: Nine patients (36%) had bilateral and ten (40%) had unilateral high-frequency sensorineural hearing loss (SNHL). Three (12%) had unilateral middle ear effusions with conductive losses persisting beyond 6 months. Only five patients (20%) had normal hearing. The high-frequency SNHL deteriorated over the first 6 months in both placebo and active treatment groups by a median 6.3 dB (p < 0.0001, Wilcoxon matched-pairs). This hearing loss subsequently improved above baseline by 1.5 dB at 18 months (p = 0.07), by 5.0 dB at 30 months (p = 0.006) and by 4.0 dB at 42 months (p = 0.01). CONCLUSION: Significant hearing loss, usually high-frequency SNHL, is a common manifestation of Fabry disease in adults. Alpha-galactosidase A replacement therapy with agalsidase alfa appears to reverse the hearing deterioration in these patients. This improvement, however, is gradual, suggesting the need for long-term ERT.     

Hearing improvement in patients with Fabry disease treated with agalsidase alfa

Aim : To describe the nature and prevalence of hearing loss in Fabry disease, and its response to enzyme replacement therapy (ERT) with agalsidase alfa. Methods : Fifteen male patients with Fabry disease were enrolled in a randomized, double-blind study and received placebo ( n = 8) or ERT ( n = 7) with agalsidase alfa for 6 months. This was followed by an open-label extension of 36 months thus far. Alongside this trial, an additional eight men and two women have so far received open-label ERT for between 6 and 30 months. Pure-tone audiometry, impedance audio-metry and otoacoustic emission testing were performed at 0 (baseline), 6, 18, 30 and 42 months. Results : Nine patients (36%) had bilateral and ten (40%) had unilateral high-frequency sensorineural hearing loss (SNHL). Three (12%) had unilateral middle ear effusions with conductive losses persisting beyond 6 months. Only five patients (20%) had normal hearing. The high-frequency SNHL deteriorated over the first 6 months in both placebo and active treatment groups by a median 6.3 dB ( p < 0.0001, Wilcoxon matched-pairs). This hearing loss subsequently improved above baseline by 1.5 dB at 18 months (p = 0.07), by 5.0 dB at 30 months ( p = 0.006) and by 4.0 dB at 42 months ( p = 0.01).
Conclusion : Significant hearing loss, usually high-frequency SNHL, is a common manifestation of Fabry disease in adults. α-Galactosidase A replacement therapy with agalsidase alfa appears to reverse the hearing deterioration in these patients. This improvement, however, is gradual, suggesting the need for long-term ERT.     

Safety of agalsidase alfa in patients with Fabry disease under 7 years

Aim: To evaluate the safety and explore the efficacy of enzyme replacement therapy (ERT) for Fabry disease with agalsidase alfa in young children enrolled in the Fabry Outcome Survey (FOS). Methods: This retrospective chart review identified eight children (mean age = 5.0 ± 1.6 [mean ± SD]) in FOS who began treatment with agalsidase alfa (0.2 mg/kg, i.v., every other week) when <7 years old. Vital signs and adverse events were monitored throughout the study period. Glomerular filtration rate (GFR) was estimated, and left ventricular mass indexed to height^2.7 (LVMi) was assessed with echocardiography. Patients received 1.2–6.7 years of treatment (mean = 4.2 years). Results: Infusion reactions occurred in three patients and were of mild or moderate severity. IgG antibodies to agalsidase alfa were found in one patient who experienced two mild and one moderate infusion reactions. Mean GFR was within the normal range at baseline and remained normal. LVMi was above the 75th percentile of age‐matched children in 5 of 6 patients evaluated at baseline. Only two patients exceeded this threshold at their last assessment. Conclusion: Long‐term observation will be needed to determine whether early initiation of ERT will prevent major organ dysfunction in these patients.     

Fabry disease during childhood: clinical manifestations and treatment with agalsidase alfa

Fabry disease is a rare X-linked disorder that leads to widespread and progressive disease manifestations, with patients at risk of premature mortality as a result of renal, cardiovascular or cerebrovascular complications. In recent years there has been a growing awareness that the first signs and symptoms of Fabry disease may begin during childhood. Studies show that clinical manifestations such as pain, hypohidrosis, gastrointestinal disturbances, angiokeratomas, cornea verticillata and acroparaesthesiae may be common in childhood and that such manifestations may become apparent during the first few years of life. Despite the early onset of these signs and symptoms, however, diagnosis is often delayed. Interest is now focused on whether enzyme replacement therapy can slow or prevent the onset of these disease manifestations. Preliminary data from two studies suggest that treatment with agalsidase alfa is well tolerated in children and that it may have beneficial clinical effects; however, further research is needed to determine whether enzyme replacement therapy can prevent the development of disease manifestations. CONCLUSION: The manifestations of Fabry disease first become apparent during childhood. It is well known that disease-associated manifestations are progressive; however, it has yet to be determined whether specific treatment with enzyme replacement therapy can prevent the development of the associated severe and life-threatening complications.     

Effects of enzyme replacement therapy with agalsidase alfa on glomerular filtration rate in patients with Fabry disease: preliminary data

Progressive deposition of globotriaosylceramide results in severe complications involving the kidney, heart and brain in both hemizygous male and heterozygous female patients with Fabry disease. Analysis of renal data from FOS - the Fabry Outcome Survey - suggests that enzyme replacement therapy with agalsidase alfa can significantly improve renal function in patients with Fabry disease, at least in those with a mild decrease in glomerular filtration rate, and may also be able to slow down the natural decline in renal function in patients with a moderate reduction in glomerular filtration rate.
Conclusion : Initial results from the large cohort of patients within FOS indicate that treatment with agalsidase alfa has beneficial effects on kidney function in patients with Fabry disease.     

Effects of enzyme replacement therapy with agalsidase alfa on glomerular filtration rate in patients with Fabry disease: preliminary data

Progressive deposition of globotriaosylceramide results in severe complications involving the kidney, heart and brain in both hemizygous male and heterozygous female patients with Fabry disease. Analysis of renal data from FOS--the Fabry Outcome Survey--suggests that enzyme replacement therapy with agalsidase alfa can significantly improve renal function in patients with Fabry disease, at least in those with a mild decrease in glomerular filtration rate, and may also be able to slow down the natural decline in renal function in patients with a moderate reduction in glomerular filtration rate. CONCLUSION: Initial results from the large cohort of patients within FOS indicate that treatment with agalsidase alfa has beneficial effects on kidney function in patients with Fabry disease.     

法布里病患儿临床特点及酶替代治疗四例初探

目的分析法布里病患儿的临床特点及使用酶替代药物治疗基本情况。方法对2014年1月至2020年7月间浙江大学医学院附属儿童医院确诊的4例法布里病患儿的临床资料、实验室检查、基因变异及治疗进行回顾性分析。临床观察其酶替代药物阿加糖酶β治疗的效果。结果 4例患儿(男2例、女2例)年龄12.4(6.0~16.8)岁,临床表现各异,其中肢端疼痛1例、少汗2例、尿崩1例,均有左心室肥厚和尿检异常,但均未发现典型皮疹及听力异常。4例患儿均结合临床症状、体征、家族史,通过α-半乳糖苷酶A酶活性、基因检测结果明确诊断。共检出3个GLA基因错义变异 c.424T>C(p.C142R)、c.335G>A(p.R112H)和c.644A>G(p.N215S)。其中前2个变异为经典型法布里病患者变异位点,后者多表现为迟发型但亦有经典型的报道。例1使用阿加糖酶β用量为每次1 mg/kg静脉泵注,每2周用药1次。患儿诉用药后疼痛强度有缓解,少汗症状得到改善。患儿在最初的2个月输注阿加糖酶β过程中未发生严重不良反应,在输注阿加糖酶β 3次后24 h尿蛋白升至1 015.6 mg,未予处理,1周后复查降至正常。结论法布里病在儿童期临床表现多样,需要多学科联合协同诊断并探讨酶替代治疗的时机,阿加糖酶β治疗患儿短期严重不良反应少见。     

Inner ear function in children with Fabry disease

Aim : The prevalence of hearing loss in patients with Fabry disease is still uncertain. This paper examines hearing loss in a group of young patients with Fabry disease. Methods : A clinical ear nose and throat examination, pure-tone air and bone conduction audiometry, speech audiometry and middle ear testing (tympanometry and acoustic reflex testing) were carried out in four girls and two boys with Fabry disease (age, 7–17 years), receiving enzyme replacement therapy (ERT). Results : None of the patients complained of a hearing disorder or suffered from hearing loss. Three female patients reported tinnitus; however, this was not reported as being a problem. One boy reported tinnitus for the first time during 6 months of ERT.
Conclusion : Based on this small sample of patients, it appears that the hearing disorders associated with Fabry disease develop mainly in adulthood. Tinnitus may be an earlier symptom than previously thought in Fabry disease.     

Early diagnosis of Fabry disease in children

Fabry disease, a rare X-linked lysosomal storage disorder, is caused by deficiency of the enzyme α-galactosidase A. The incidence, ranging from one over 40 000 to one over 11 7000 worldwide is probably underestimated due to its unspecific pattern of presentation. The symptoms, including neurological, gastrointestinal, renal, ophthalmological and dermatologic manifestations, start in childhood and adolescence, cause a significant morbidity and are likely to affect the patient's quality of life. Furthermore, Anderson-Fabry disease always progress leading to a multiorgan dysfunction and life-threatening complications with end-stage renal disease, cardiomyopathy and high incidence of stroke. The estimated life in untreated patients is reduced by 15-20 years respectively in men and women. The enzyme replacement therapy, available in Europe from 2001, results in a reduction of major organs failure, morbidity and mortality. We present the case of an 8-year-old male admitted to our Division for overweight with a previous history of acroparesthesias, severe acute pain in hands and feet, abdominal pain, diarrhoea, constipation, bitemporal headache, dyshidrosis, recurrent fever, exercise intolerance and reduced quality of life. The physical examination was within normal limits. The α-galactosidase A activity was deficient in plasma and normal in peripheral leukocytes; the GLA gene showed a nucleotide substitution c.352C>T (p.Arg 118 Cys) in the eson 2 with a residual enzyme activity of the 29% suggesting the diagnosis of Fabry disease. Blood and urine chemistry, the slit-lamp examination and MRI of kidneys, heart and brain excluded any major organ involvement. The enzyme replacement therapy was then started almost three months ago using agasidase alfa at a dose of 0.2 mg/kg infused intravenously every two weeks but, unfortunately, no relief in the symptoms have been reported so far without any severe adverse reactions. This case report aims to point out the importance of an early diagnosis in order to prevent the progression of the disease, the multiorgan failure and to improve the long-term prognosis.     

Monitoring the clinical and biochemical response to enzyme replacement therapy in three children with Fabry disease

Fabry disease is an X-linked disorder of glycosphingolipid metabolism resulting from a deficiency of the lysosomal enzyme -galactosidase A. This leads to the progressive accumulation of glycosphingolipids in lysosomes of most visceral tissues and in body fluids. Following successful clinical trials in adults, two recombinant enzyme preparations of -galactosidase have recently been licensed in Europe for the treatment of Fabry disease and treatment in children has commenced. We now report the clinical findings and the levels of globotriaosylceramide in plasma and urine in three boys who have been treated with enzyme replacement therapy (agalsidase beta, Fabrazyme), 1 mg/kg for 2 years. In one boy there was a rapid improvement in all the clinical and biochemical parameters measured. This has been maintained. In the other two boys, who are siblings, there was no measurable clinical improvement after 1 year and the levels of globotriaosylceramide in plasma and urine, although lower than before treatment, were still considerably elevated. There was no evidence of blocking or neutralising antibodies so the dose of enzyme was increased to 2 mg/kg at 74 weeks of therapy. At 2 years their pain scores had improved but this was not accompanied by any reduction in the plasma or urine globotriaosylceramide levels. Conclusion:measurement of globotriaosylceramide in plasma and urine may not be the most appropriate marker to monitor the progression of treatment by enzyme replacement therapy in all patients. Certainly the subjective clinical improvement in the two brothers in this report outweighed the objective biochemical findings.Abbreviations CTH globotriasosylceramide - ERT enzyme replacement therapy - FA fatty acid - LCB sphingosine - MS/MS tandem mass spectrometry