Treatment of Fabry's Disease with the Pharmacologic Chaperone Migalastat.

BACKGROUND: Fabry's disease, an X-linked disorder of lysosomal α-galactosidase deficiency, leads to substrate accumulation in multiple organs. Migalastat, an oral pharmacologic chaperone, stabilizes specific mutant forms of α-galactosidase, increasing enzyme trafficking to lysosomes. METHODS: The initial assay of mutant α-galactosidase forms that we used to categorize 67 patients with Fabry's disease for randomization to 6 months of double-blind migalastat or placebo (stage 1), followed by open-label migalastat from 6 to 12 months (stage 2) plus an additional year, had certain limitations. Before unblinding, a new, validated assay showed that 50 of the 67 participants had mutant α-galactosidase forms suitable for targeting by migalastat. The primary end point was the percentage of patients who had a response (≥50% reduction in the number of globotriaosylceramide inclusions per kidney interstitial capillary) at 6 months. We assessed safety along with disease substrates and renal, cardiovascular, and patient-reported outcomes. RESULTS: The primary end-point analysis, involving patients with mutant α-galactosidase forms that were suitable or not suitable for migalastat therapy, did not show a significant treatment effect: 13 of 32 patients (41%) who received migalastat and 9 of 32 patients (28%) who received placebo had a response at 6 months (P=0.30). Among patients with suitable mutant α-galactosidase who received migalastat for up to 24 months, the annualized changes from baseline in the estimated glomerular filtration rate (GFR) and measured GFR were -0.30±0.66 and -1.51±1.33 ml per minute per 1.73 m(2) of body-surface area, respectively. The left-ventricular-mass index decreased significantly from baseline (-7.7 g per square meter; 95% confidence interval [CI], -15.4 to -0.01), particularly when left ventricular hypertrophy was present (-18.6 g per square meter; 95% CI, -38.2 to 1.0). The severity of diarrhea, reflux, and indigestion decreased. CONCLUSIONS: Among all randomly assigned patients (with mutant α-galactosidase forms that were suitable or not suitable for migalastat therapy), the percentage of patients who had a response at 6 months did not differ significantly between the migalastat group and the placebo group. (Funded by Amicus Therapeutics; ClinicalTrials.gov numbers, NCT00925301 [study AT1001-011] and NCT01458119 [study AT1001-041].).

Pegunigalsidase alfa, a novel PEGylated enzyme replacement therapy for Fabry disease, provides sustained plasma concentrations and favorable pharmacodynamics: A 1-year Phase 1/2 clinical trial.

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.

A Case Report of Kidney After Heart Transplant in Patient With Fabry Disease.

Fabry disease is an X-linked inherited lysosomal storage disorder caused by a mutation in the gene encoding the enzyme α-galactosidase A. It is characterized by the accumulation of globotriaosylceramide in different tissues, resulting in a wide range of clinical presentations. Fabry cardiomyopathy and Fabry nephropathy are the disease's 2 most important life-threatening manifestations and can contribute to higher morbidity and mortality. Heart and kidney transplants can play a major role in patients with Fabry disease who develop end organ damage. We report a case of a successful heart transplant in a male patient with Fabry disease at the age of 62, followed by a kidney transplant later at the age of 69. He has had an uneventful post-transplant course and has been tolerating maintenance immunosuppression and enzyme replacement therapy with recombinant human α-galactosidase A.

A CD3+ count-based thymoglobulin induction regimen permits delayed introduction of calcineurin inhibitors in kidney transplantation.

BACKGROUND: Withholding calcineurin inhibitors (CNIs) can be considered when graft function is inadequate following kidney transplantation (KT). Thymoglobulin (rATG) can be used to prevent acute rejection while CNIs are being withheld. Here, we report our results of a novel CNI-sparing induction protocol, which utilizes a CD3+ cell count-based rATG treatment regimen when delayed graft function (DGF) develops in the immediate postoperative period. METHODS: In a cohort of 153 consecutive deceased-donor KT recipients, all received a single intraoperative dose of basiliximab; 84 subsequently developed DGF and therefore received rATG (rATG+ group), while 69 demonstrated immediate graft function and received CNIs (rATG- group). RESULTS: In the rATG+ group, mean duration of therapy was 8.5±6.0 d, permitting CNI initiation to be delayed until postoperative day 10.3±6.2. Cumulative dose of rATG was only 5.1±4.5 mg/kg while targeting CD3+ counts of ≤30 cells/mm3. CD3+ counts were reduced to a mean of 16.7±17.0 cells/mm3 during therapy. At one yr, patient and graft survival rates were 97.6% and 92.9%, respectively, while the frequency of infections and malignancies were not significantly increased compared to the rATG- group. CONCLUSION: A unique induction regimen successfully delayed CNI initiation by using modest doses of rATG to deplete CD3+ cells, while yielding excellent long-term graft outcome without increased risk of infection or malignancy.

Dialysis disequilibrium syndrome leading to sudden brain death in a chronic hemodialysis patient.

Dialysis disequilibrium syndrome (DDS) is a rare central nervous system (CNS) disease which develops in patients receiving hemodialysis (HD). Although it has been reported in patients receiving chronic HD, DDS is more common during or immediately after the first HD treatment. The exact incidence of DDS is unknown. Death in DDS is an extremely rare phenomenon and to the best of our knowledge only 9 cases have been reported showing this association. We present a unique case of a 42-year-old female on chronic HD, and no prior history of CNS disease, who developed brain death in the setting of DDS 2 hours into the dialysis treatment. A literature review of all previously reported cases was performed.

Non Uremic Calciphylaxis Post Liver Transplantation: A Case Report and Literature Review of an Unusual Presentation of a Rare Disease.

BACKGROUND Calciphylaxis results from abnormal calcification of small to medium sized vessels, resulting in painful ischemic necrosis of the surrounding tissues. It is most commonly seen in patients with end stage renal disease on dialysis, but has also been reported in patients with preserved renal function. CASE REPORT We report a case of non uremic calciphylaxis in a 65-year-old female who presented with painful skin lesions and ulcerations involving both thighs one month after receiving a liver transplantation. She was treated with sodium thiosulfate along with wound care and hyperbaric oxygen with complete resolution of the lesions, but with residual scarring. CONCLUSIONS Non uremic calciphylaxis is a rare phenomenon that is poorly understood. It should be in the differential of unexplained skin lesions even in the absence of renal insufficiency. Sodium thiosulfate plays a role in treatment, but wound care remains the main focus of treatment.

Association of Slow Graft Function with Long-Term Outcomes in Kidney Transplant Recipients.

BACKGROUND Whether slow graft function (SGF) represents an intermediate phenotype between immediate graft function (IGF) and delayed graft function (DGF) in kidney transplant recipients is unknown. MATERIAL AND METHODS In a retrospective cohort analysis of 1,222 kidney transplant recipients, we classified patients as having IGF, SGF, and DGF using two different schemas. SGF was defined as serum creatinine (Cr) ≥3.0 mg/dL by postoperative day 5 in Schema 1, and in Schema 2, SGF was defined as Cr >1.5 mg/dL plus a creatinine reduction ratio <20% between postoperative days 1 and 3. A complementary log-log model was used to examine the association of graft function with graft survival and patient survival. RESULTS Mean age of study patients was 51.5±13.3 years, 59.9% were male, and 66.7% were white. In Schema 1, SGF and DGF were associated with comparable increases in risk of graft failure compared to IGF (hazard ratio (HR) 1.46, 95% confidence intervals (CI) 1.02-2.10 for SGF and HR 1.56, CI 1.11-2.22 for IGF); estimates were similar for Schema 2 (HR 1.52, CI 1.05-2.20 for SGF and HR 1.54, CI 1.10-2.17 for IGF). However, for mortality, outcomes for SGF were similarly to IGF, both SGF and IGF were associated with lower risk relative to DGF (HR 0.54, CI 0.36-0.80 for SGF in Schema 1; HR 0.58, CI 0.39-0.85 for SGF in Schema 2). CONCLUSIONS These findings suggest that SGF may be a marker for graft failure but not for mortality, and SGF may therefore represent a phenotype separate from IGF and DGF.

Clinical characteristics and risk factors associated with mortality in calcific uremic arteriolopathy.

BACKGROUND: Calcific uremic arteriolopathy (CUA) is an often-fatal condition in dialysis patients. The clinical descriptions and treatments of CUA patients have been confined mostly to case reports. We report a comprehensive characterization of CUA and its associated diagnosis, treatment patterns, and outcome. METHODS: An internet-based registry collected information about CUA in dialysis patients. Univariate analysis using Cox proportional hazards models estimated hazard ratios of the association between clinical characteristics, laboratory values, and treatments with all-cause mortality. RESULTS: A total of 117 CUA patients had adequate information for analysis. The majority of patients (56.7%) were diagnosed clinically, with only 32.5% biopsied. Debridement was undertaken in 42.6% of cases. Intravenous sodium thiosulfate (STS) was initiated in 54.7% of patients; most received ≥ 12.5 g of STS (98.3%) for < 3 months (79.7%). Mean parathyroid hormone (PTH) and phosphorus (P) were 459 ± 492 pg/mL and 6.3 ± 2.1 mg/dL, respectively. A total of 24 patients (21.6%, of 111 with information) died, with a median survival time of 2.9 months. In univariate analysis, higher mortality was observed in patients with cardiovascular disease (CVD; HR = 10.47; 95% CI 1.40-78.38), those taking warfarin at time of diagnosis (HR = 2.74; 95% CI 1.16-6.51), and those who had both diabetes (DM) and CVD and who were taking warfarin (HR = 13.41; 95% CI 1.66-109.29). CONCLUSIONS: In real-world clinical practice, there is substantial variability in the diagnosis and treatment of CUA. There is usually only modest derangement of bone and mineral parameters at the time of diagnosis. Death is common. The presence of CVD and use of warfarin may influence clinical outcome after diagnosis of CUA.