Long-term safety of enzyme replacement therapy with agalsidase alfa in patients with Fabry disease: post-marketing extension surveillance in Japan

Fabry disease is a rare inherited X-linked metabolic disorder in which deficient alpha-galactosidase A activity causes progressive build-up of globotriaosylceramide (Gb3) and multi-system dysfunction. Following approval of agalsidase alfa for Fabry disease in Japan in 2006, an 8-year all-case post-marketing surveillance (PMS) showed that the treatment was well tolerated and effective for managing disease progression in adult Japanese patients. The present nationwide prospective observational study extended the initial PMS by enrolling patients who continued agalsidase alfa treatment after the initial 8-year period in a 6.5-year extension survey. Patient information from the initial PMS and the extension survey was evaluated as a single data set (observation period: February 2007-September 2021). Of 493 patients in the initial PMS, 129 (45.0% male classic, 6.2% male non-classic, 48.8% female heterozygous phenotype) consented to participate in the extension survey and were included in the analysis. The mean duration of treatment was 9.6 years. A total of 145 adverse drug reactions (ADRs) occurred in 31 patients (24%), and 22 serious ADRs occurred in 12 patients (9.3%). Although serious cardiac, renal, or cerebrovascular adverse events decreased in frequency over time in male patients, serious cardiac events continued to occur in female patients, who showed higher incidence of cardiac complications at baseline. No new safety concerns were identified. Additionally, long-term agalsidase alfa treatment sustained the initial reduction in Gb3 concentrations without increasing the rate of anti-agalsidase antibody positivity. These findings suggest that agalsidase alfa treatment demonstrates continued safety and sustains patients' clinical course over the long term.

Consensus recommendations for the treatment and management of patients with Fabry disease on migalastat: a modified Delphi study

Objective

Fabry disease is a progressive disorder caused by deficiency of the α-galactosidase A enzyme (α-Gal A), leading to multisystemic organ damage with heterogenous clinical presentation. The addition of the oral chaperone therapy migalastat to the available treatment options for Fabry disease is not yet universally reflected in all treatment guidelines. These consensus recommendations are intended to provide guidance for the treatment and monitoring of patients with Fabry disease receiving migalastat.

Methods

A modified Delphi process was conducted to determine consensus on treatment decisions and monitoring of patients with Fabry disease receiving migalastat. The multidisciplinary panel comprised 14 expert physicians across nine specialties and two patients with Fabry disease. Two rounds of Delphi surveys were completed and recommendations on the use of biomarkers, multidisciplinary monitoring, and treatment decisions were generated based on statements that reached consensus.

Results

The expert panel reached consensus agreement on 49 of 54 statements, including 16 that reached consensus in round 1. Statements that reached consensus agreement are summarized in recommendations for migalastat treatment and monitoring, including baseline and follow-up assessments and frequency. All patients with Fabry disease and an amenable mutation may initiate migalastat treatment if they have evidence of Fabry-related symptoms and/or organ involvement. Treatment decisions should include holistic assessment of the patient, considering clinical symptoms and organ involvement as well as patient-reported outcomes and patient preference. The reliability of α-Gal A and globotriaosylsphingosine as pharmacodynamic response biomarkers remains unclear.

Conclusion

These recommendations build on previously published guidelines to highlight the importance of holistic, multidisciplinary monitoring for patients with Fabry disease receiving migalastat, in addition to shared decision-making regarding treatments and monitoring throughout the patient journey. GRAPHICAL ABSTRACT.

Twenty years of the Fabry Outcome Survey (FOS): insights, achievements, and lessons learned from a global patient registry

Background

Patient registries provide long-term, real-world evidence that aids the understanding of the natural history and progression of disease, and the effects of treatment on large patient populations with rare diseases. The year 2021 marks the 20th anniversary of the Fabry Outcome Survey (FOS), an international, multicenter, observational registry (NCT03289065). The primary aims of FOS are to broaden the understanding of Fabry disease (FD), an X-linked lysosomal storage disorder, and to improve the clinical management of affected patients. Here, we review the history of FOS and the analyses and publications disseminated from the registry, and we discuss the contributions FOS studies have made in understanding FD.

Results

FOS was initiated in April 2001 and, as of January 2021, 4484 patients with a confirmed diagnosis and patient informed consent have been enrolled from 144 centers across 26 countries. Data from FOS have been published in nearly 60 manuscripts on a wide variety of topics relevant to FD. Analyses of FOS data have investigated the long-term effectiveness and safety of enzyme replacement therapy (ERT) with agalsidase alfa and its effects on morbidity and mortality, as well as the benefits of prompt and early treatment with agalsidase alfa on the progression of cardiomyopathy and the decline in renal function associated with FD. Based on analyses of FOS data, ERT with agalsidase alfa has also been shown to improve additional signs and symptoms of FD experienced by patients. FOS data analyses have provided a better understanding of the natural history of FD and the specific populations of women, children, and the elderly, and have provided practical tools for the study of FD. FOS has also provided methodology and criteria for assessing disease severity which contributed to the continuous development of medical practice in FD and has largely improved our understanding of the challenges and needs of long-term data collection in rare diseases, aiding in future rare disease real-world evidence studies.

Conclusion

FOS over the last 20 years has substantially increased the scientific knowledge around improved patient management of FD and continues to expand our understanding of this rare disease.

Translation of quality of life scale for pediatric patients with Fabry disease in Japan

Introduction

Methods

Results

Conclusion

New mutation in Fabry disease: c.448delG, first phenotypic description

Fabry disease (FD) (Anderson-Fabry disease, OMIM 301500) is a genetic disorder caused by a pathogenic variant in the GLA gene on chromosome Xq22 that produces a deficiency in the lysosomal enzyme alpha-galactosidase A.

It is transmitted as an X-linked trait, although de novo mutations have been described. The objective of this report is to describe the clinical characteristics of a patient with FD who is a carrier of a mutation not previously studied, in order to provide information on the genotype-phenotype correlation in this pathology.

38-year-old patient who consulted Neurology for positional vertigo. He also reported acroparesthesia, anhidrosis, heat intolerance and episodes of abdominal pain, with postprandial discomfort from 10 years of age. Physical examination showed horizonto-rotatory nystagmus in both looks, the rest of the neurological evaluation did not present abnormalities. The presence of umbilical and thighs angiokeratomas was identified. Determination of Alpha-Galactosidase in blood was requested: 0.34 μmol/l/h (2.10–10.51 μmol/l/h). Genetic analysis detected a deletion of a guanine at position 448, in exon 3 of the GLA gene (c.448delG). This mutation was considered to be pathogenic, confirming the diagnosis of FD, although it is not described in the data bases. Genetic counseling and a family pedifree study were performed without finding relatives with this variant of the GLA gene or a family history of FD, which suggests a de novo mutation.

Symptoms and Quality of Life in Patients with Fabry Disease: Results from an International Patient Survey

INTRODUCTION

Fabry disease is an X-linked lysosomal storage disorder caused by a deficiency of α-galactosidase A. Symptoms include neuropathic pain and gastrointestinal problems, such as diarrhoea. To inform and support the design of a Phase III clinical trial for a new oral treatment for Fabry disease, this study evaluated patients' experiences of Fabry disease symptoms, the impact of symptoms on their quality of life, and their views on participating in clinical trials.

METHODS

An online survey questionnaire was distributed to patients with Fabry disease, through relevant patient organisations. The questionnaire consisted mainly of quantitative, closed questions with pre-defined response options. Fabry-specific pain intensity and its impact on quality of life were rated on a scale from 0 to 10.

RESULTS

In total, 367 patients completed the survey, of whom half reported frequent pain, moderate to severe pain, and pain in their hands and feet. Pain frequency, intensity and location were similar for males and females. There was no clear association between Fabry-specific pain and the use of enzyme replacement therapy (ERT), with moderate to severe pain reported by 80.4% of participants receiving ERT and by 75.0% of participants not receiving ERT. Of participants who were receiving ERT, 35.7% said they were willing to discontinue it to take part in a clinical trial testing a new oral drug for treating Fabry disease. Gastrointestinal symptoms were more heterogeneous in nature and frequency than Fabry-specific pain, but still affected a significant proportion of participants.

CONCLUSIONS

Both male and female patients with Fabry disease experience significant Fabry-specific pain, which affects their quality of life. Furthermore, frequent diarrhoea affects many patients. The symptoms occur independently of the use of ERT. This suggests the healthcare needs of patients with Fabry disease are not being fully met, and additional treatments are required to improve symptoms and quality of life.

FUNDING

This study was sponsored by Actelion Pharmaceuticals Ltd. Study sponsorship was transferred to Idorsia Pharmaceuticals Ltd in July 2018.