Prompt Agalsidase Alfa Therapy Initiation is Associated with Improved Renal and Cardiovascular Outcomes in a Fabry Outcome Survey Analysis.

BACKGROUND: The timing of enzyme replacement therapy initiation in patients with Fabry disease is hypothesized to be critical. In this study, we used Fabry Outcome Survey data to assess the impact of prompt versus delayed initiation of treatment with agalsidase alfa on cardiovascular and renal events in patients with Fabry disease. METHODS: Available genetic data at baseline were used to define patients with mutations associated with classical versus late-onset Fabry disease. Time to cardiovascular or renal events, from treatment initiation until 120 months, was compared for patients in prompt versus delayed groups. "Prompt" was defined as treatment initiation <24 months from symptom onset (analysis A) or diagnosis (analysis B), and "delayed" was defined as ≥24 months from symptom onset (analysis A) or diagnosis (analysis B). Kaplan-Meier curves and Log rank tests compared event-free probabilities and time to first event. Multivariate Cox regression estimated hazard ratios (HRs). RESULTS: Analysis by time from symptom onset included 1374 patients (172 prompt, 1202 delayed). In a multivariate Cox regression analysis, prompt versus delayed treatment initiation significantly reduced the probability of cardiovascular (HR=0.62; P<0.001) and renal (HR=0.57; P=0.001) events. History of cardiovascular or renal events was associated with increased risk of respective events. Analysis by time from diagnosis included 2051 patients (1006 prompt, 1045 delayed). In a multivariate Cox regression analysis, prompt treatment initiation significantly reduced the probability of cardiovascular events (HR=0.83; P=0.003) after adjusting for history of cardiovascular events, sex, and age at treatment initiation. Univariate analysis showed that the probability of renal events was significantly lower in the prompt group (P=0.018); this finding was attenuated in the multivariate Cox regression analysis. CONCLUSION: This analysis suggests that prompt treatment initiation with agalsidase alfa provided better renal and cardiovascular outcomes than delayed treatment in patients with Fabry disease.

Effects of Baseline Left Ventricular Hypertrophy and Decreased Renal Function on Cardiovascular and Renal Outcomes in Patients with Fabry Disease Treated with Agalsidase Alfa: A Fabry Outcome Survey Study.

PURPOSE: The initiation of enzyme-replacement therapy prior to the occurrence of substantial and irreversible organ damage in patients with Fabry disease is of critical importance. The Fabry Outcome Survey is an international disease registry of patients with a confirmed diagnosis of Fabry disease. In this study, data from the Fabry Outcome Survey were used for the assessment of the risks for cardiovascular and renal events in patients who received agalsidase alfa treatment. METHODS: Eligible patients were males and females aged ≥18 years with Fabry disease treated with agalsidase alfa. Cardiovascular events included myocardial infarction, left ventricular hypertrophy (LVH), heart failure, arrhythmia, conduction abnormality, and cardiac surgery. Renal events included dialysis, transplantation, and renal failure. Kaplan-Meier curves and log-rank tests were used for comparing event-free probabilities and time to first cardiovascular or renal event, from agalsidase alfa initiation to a maximum of 120 months, in patients with LVH versus normal left ventricular mass index (LVMI; ≤50 g/m2.7 in males and ≤48 g/m2.7 in females) at treatment initiation (baseline), and in patients with a low estimated glomerular filtration rate (eGFR; <90 mL/min/1.73 m2) versus normal eGFR at baseline. Multivariate Cox regression analysis was used for examining the association between key study variables and the risks for cardiovascular and renal events. FINDINGS: Among the 560 patients (269 males; 291 females) with available LVMI data, 306 (55%) had LVH and 254 (45%) had normal LVMI at baseline. The risk for a cardiovascular event was higher in the subgroup with LVH versus normal LVMI at baseline (hazard ratio [HR] = 1.57; 95% CI, 1.21-2.05; P < 0.001), but the risk for a renal event was similar between the 2 subgroups (HR = 1.90; 95% CI, 0.94-3.85; P = 0.074). Among the 1093 patients (551 males; 542 females) with available eGFR data, 433 (40%) had a low eGFR and 660 (60%) had a normal eGFR at baseline. The subgroup with a low eGFR at baseline had a significantly higher risk for a cardiovascular event (HR = 1.33; 95% CI, 1.04-1.70; P = 0.021) or a renal event (HR = 5.88; 95% CI, 2.73-12.68; P < 0.001) compared with patients with a normal eGFR at baseline. IMPLICATIONS: In the present study, the presence of LVH and/or reduced renal function at agalsidase alfa initiation was associated with a significantly higher risk for a cardiovascular or renal event, indicating that cardiovascular and renal pathologies in Fabry disease may be inter-related. Early initiation of agalsidase alfa treatment prior to the onset of severe organ damage may improve outcomes. ClinicalTrials.gov identifier: NCT03289065.

Analysis of Renal and Cardiac Outcomes in Male Participants in the Fabry Outcome Survey Starting Agalsidase Alfa Enzyme Replacement Therapy Before and After 18 Years of Age.

PURPOSE: To determine the impact of initiating enzyme replacement therapy (ERT) with agalsidase alfa early in the course of Fabry disease, we evaluated renal and cardiac outcomes for ≤10 years after ERT initiation in males from the Fabry Outcome Survey (FOS). PATIENTS AND METHODS: Male patients from FOS were stratified into three cohorts by age at ERT initiation: ≤18 years (cohort 1), >18 and ≤30 years (cohort 2), and >30 years (cohort 3). Analysis included age at symptom onset, diagnosis, and ERT initiation; ERT duration; FOS-Mainz Severity Score Index (FOS-MSSI); estimated glomerular filtration rate (eGFR); proteinuria level; and left ventricular mass indexed to height (LVMI). Mixed-effect models estimated renal and cardiac outcomes during follow-up between and within cohorts. FINDINGS: The analysis included 560 male patients: 151 (27.0%) in cohort 1, 155 (27.7%) in cohort 2, and 254 (45.4%) in cohort 3. Mean±SD duration of ERT for cohorts 1, 2, and 3 was 6.3±4.3, 8.6±4.9, and 7.9±4.9 years, respectively. Mean±SD baseline FOS-MSSI scores increased with age from 9.8±7.2 in cohort 1 to 24.7±11.4 in cohort 3. Cohort 3 showed the lowest baseline mean±SD value for eGFR (87.1±29.0 mL/min/1.73m2) and highest baseline mean±SD values for proteinuria (801.9±952.6 mg/day) and LVMI (56.7±16.0 g/m2.7) among the three cohorts. Evaluation of mean annual rates of change in eGFR, proteinuria, and LVMI revealed no significant differences in any parameter for cohort 1. For cohort 2, proteinuria and LVMI remained stable, whereas eGFR significantly deteriorated annually (-1.12 mL/min/1.73m2; P<0.001). Cohort 3 demonstrated significant annual deteriorations in eGFR (-2.60 mL/min/1.73m2; P<0.001), proteinuria (+34.10 mg/day; P<0.001), and LVMI (+0.59 g/m2.7; P=0.001). IMPLICATIONS: Renal and/or cardiac disease progression appears attenuated in patients starting ERT in childhood or early adulthood versus patients starting ERT in later adulthood. These findings support early ERT initiation in Fabry disease. ClinicalTrials.gov identifier: NCT03289065.

Inter-assay variability influences migalastat amenability assessments among Fabry disease variants.

Fabry disease is a lysosomal storage disorder caused by mutations in the GLA gene that encodes for the lysosomal enzyme α-galactosidase A (α-Gal A). Reduced or absent α-Gal A activity leads to substrate accumulation and deleterious effects in multiple organs. Migalastat is a pharmacological chaperone that may stabilize the enzyme in specific GLA variants, considered amenable, assisting enzyme trafficking to lysosomes and thus increasing enzyme activity. Using a good laboratory practice (GLP)-validated human embryonic kidney cell (HEK)-based (GLP-HEK) amenability assay established during the clinical development of migalastat, approximately one-third of GLA variants are reported to be amenable to migalastat. On the basis of this biochemical amenability, migalastat is approved for use in patients with specific GLA variants. In this study, the reproducibility of the amenability assay was assessed by evaluation of 59 GLA variants for α-Gal A activity in the presence and absence of migalastat. As for the GLP-HEK assay, variants were considered amenable when there was both an absolute increase in enzyme activity of ≥3% wild-type and a relative increase in enzyme activity ≥1.2 fold over baseline following incubation with migalastat. Six of the 59 variants tested here did not match the classification of amenability reported using the GLP-HEK assay. Linear regression and Bland-Altman analyses, comparing data from all variants with and without migalastat, provided additional evidence for a lack of assay reproducibility. Data from the GLP-HEK assay (and the resulting classification of amenability) can determine treatment strategy and, ultimately, patient outcomes, so discrepancies between amenability assay data could be a cause for concern for physicians managing patients with Fabry disease.

Evaluating enzyme replacement therapies for Anderson-Fabry disease: commentary on a recent report.

Anderson-Fabry disease (AFD) is a rare lysosomal storage disorder. Randomized controlled clinical trials (RCTs) are preferred as the highest category of evidence, but limited availability of robust evidence in rare diseases may necessitate the use of less rigorous evidence. An analysis of cohort studies of enzyme replacement therapies for AFD published in 2017 by El Dib and coworkers made treatment recommendations that contradict previously published findings from RCTs and a systematic Cochrane review. Our commentary outlines concerns regarding selection criteria and statistical methods with their analysis.

AN OVERVIEW OF NURSES' MANAGEMENT OF SECONDARY HYPERPARATHYROIDISM: HOW IS EUROPE DOING?

BACKGROUND: Nurses have an important role to play in the management of secondary hyperparathyroidism (SHPT). An online survey conducted by the European Dialysis and Transplant Nurses Association/European Renal Care Association (EDTNA/ERCA) in conjunction with Amgen (Europe) GmbH surveyed nephrology nurses' knowledge of secondary hyperparathyroidism, treatment targets, current treatments, patient adherence and nephrology nurse training education needs. The survey's aim was to establish common practices being used by nurses in the management of secondary hyperparathyroidism and to identify nephrology nurses' training and educational needs in order to improve patient care. DESIGN: Descriptive study. MEASUREMENTS: An online survey of multiple choice and closed questions. PARTICIPANTS: A sample of nephrology nurses from Spain, Italy, France and the Netherlands. RESULTS: A total of 111 nurses completed the questionnaire (98% response rate, 82% of which were fully completed). Collected data revealed that there were specific aspects of SHPT patient management where nurses lacked confidence, despite the majority of respondents having 15 years nephrology nursing experience. These aspects included explaining the disorder and therapies to patients, managing side effects of drugs and appreciating the significance of controlling biochemical targets. Over 40% of the respondents felt they did not have sufficient training to support patients who were non-compliant. CONCLUSION: Nursing skills are integral to SHPT patient management as part of the multidisciplinary approach. The nurse's role is particularly important in patient assessment and monitoring, and in the provision of patient education and support, particularly with treatment adherence. Nephrology nurses who are better informed about SHPT and who receive training on practical patient care may improve the care of patients.

Cinacalcet normalizes serum calcium in a double-blind randomized, placebo-controlled study in patients with primary hyperparathyroidism with contraindications to surgery.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is diagnosed by the presence of hypercalcemia and elevated or nonsuppressed parathyroid hormone (PTH) levels. Although surgery is usually curative, some individuals fail or are unable or unwilling to undergo parathyroidectomy. In such individuals, targeted medical therapy may be of value. Cinacalcet normalized calcium level and lowered PTH in patients with PHPT in several phase 2 and open-label studies. We compared cinacalcet and placebo in subjects with PHPT unable to undergo parathyroidectomy. DESIGN: Phase 3, double-blind, multi centere, randomized, placebo-controlled study. METHODS: Sixty-seven subjects (78% women) with moderate PHPT were randomized (1:1) to cinacalcet or placebo for ≤28 weeks. MAIN OUTCOME MEASURE: Achievement of a normal mean corrected total serum calcium concentration of ≤10.3 mg/dl (2.575 mmol/l). RESULTS: Baseline median (quartile 1 (Q1), Q3) serum PTH was 164.0 (131.0, 211.0) pg/ml and mean (s.d.) serum Ca was 11.77 (0.46) mg/dl. Serum Ca normalized (≤10.3 mg/dl) in 75.8% of cinacalcet- vs 0% of placebo-treated subjects (P<0.001). Corrected serum Ca decreased by ≥1.0 mg/dl from baseline in 84.8% of cinacalcet- vs 5.9% of placebo-treated subjects (P<0.001). Least squares mean (s.e.m.) plasma PTH change from baseline was -23.80% (4.18%) (cinacalcet) vs -1.01% (4.05%) (placebo) (P<0.001). Similar numbers of subjects in the cinacalcet and placebo groups reported adverse events (AEs) (27 vs 20) and serious AEs (three vs four). Most commonly reported AEs were nausea and muscle spasms. CONCLUSIONS: These results demonstrate that cinacalcet normalizes serum calcium in this PHPT population and appears to be well tolerated.

Urinary concentrating defect in hypothyroid rats: role of sodium, potassium, 2-chloride co-transporter, and aquaporins.

Hypothyroidism is associated with impaired urinary concentrating ability in humans and animals. The purpose of this study was to examine protein expression of renal sodium chloride and urea transporters and aquaporins in hypothyroid rats (HT) with diminished urinary concentration as compared with euthyroid controls (CTL) and hypothyroid rats replaced with L-thyroxine (HT+T). Hypothyroidism was induced by aminotriazole administration. Body weight, water intake, urine output, solute and urea excretion, serum and urine osmolality, serum creatinine, 24-h creatinine clearance, and fractional excretion of sodium were comparable among the three groups. However, with 36 h of water deprivation, HT rats demonstrated significantly greater urine flow rates and decreased urine and medullary osmolality as compared with CTL and HT+T rats at comparable plasma vasopressin concentrations. Western blot analyses revealed decreased renal protein abundance of transporters, including Na-K-2Cl, Na-K-ATPase, and NHE3, in HT rats as compared with CTL and HT+T rats. Protein abundance of renal AQP1 and urea transporters UTA(1) and UTA(2) did not differ significantly among study groups. There was however a significant decrease in protein abundance of AQP2, AQP3, and AQP4 in HT rats as compared with CTL and HT+T rats. These findings demonstrate a decrease in the medullary osmotic gradient secondary to impaired countercurrent multiplication and downregulation of aquaporins 2, 3, and 4 as contributors to the urinary concentrating defect in the hypothyroid rat.

Effects of angiotensin receptor blockade on haemodynamics and gene expression after myocardial infarction.

INTRODUCTION: Despite the fact that congestive heart failure (CHF) remains the most common disease in the developed world and has been extensively studied, there is little known about the molecular and cellular mechanisms of cardiac dysfunction. Angiotensin has been implicated as a mediator of cardiac injury; however, the mechanisms of its action have not been delineated. The objective of this study was to examine the relationship between the haemodynamic and molecular events during cardiac dysfunction and the role of the angiotensin system. STUDY DESIGN: We examined the effects of the angiotensin receptor blocker, valsartan, on changes in the haemodynamic and gene expression patterns in a postmyocardial infarction model in the rat. METHODS: Myocardial infarction (MI) was induced in rats by coronary artery ligation. Cardiac haemodynamics were monitored using echocardiography. Gene expression profiles after myocardial infarction were identified using Affymetrix Genechip oligonucleotide arrays. RESULTS: Myocardial contractility, as assessed by cardiac output and left ventricle (LV) fraction of shortening, was reduced in untreated animals by week 3 after MI (p < 0.05 versus baseline), and preserved with valsartan treatment as observed by the nonsignificant changes versus baseline. LV dilatation, as demonstrated by increases in LV systolic and diastolic diameters, developed by week 3 in untreated animals (p < 0.05 versus baseline) while valsartan-treated animals were protected and showed no significant increases in diameter size compared with baseline. LV hypertrophy, as shown by LV posterior wall thickness, was more profound in untreated animals (p < 0.05 versus baseline) than in those treated with valsartan at weeks 3 and 4. Changes in gene expression at 4 weeks after MI included those encoding muscle-specific genes, fibrous tissue proliferation, immune response and various others. Treatment with valsartan reversed these changes in 67% of overexpressed genes and 83% of underexpressed genes. CONCLUSION: Angiotensin receptor blockade with valsartan was found to protect cardiac function, and this beneficial effect was accompanied by a reversal of changes in gene expression induced by MI.