Cardiac involvement in MPS patients: incidence and response to therapy in an Italian multicentre study

Real-world pharmacovigilance analysis of galsulfase: a study based on the FDA adverse event reporting system (FAERS) database

Background

Associated with enzyme deficiencies causing glycosaminoglycans (GAGs) accumulation, mucopolysaccharidosis type VI (MPS VI) is lysosomal storage disorder. In the treatment of MPS VI, galsulfase (Naglazyme) is commonly used as an enzyme replacement therapy (ERT). There remains a need for comprehensive real-world data on its safety and associated adverse events (AEs).

Objective

An analysis of the FDA Adverse Event Reporting System (FAERS) database will be conducted to identify potential risks and adverse reactions associated with galsulfase in real-life settings.

Methods

The FAERS database was used to extract data from Q2 2005 to Q4 2023. A total of 20,281,876 reports were analyzed after duplicate elimination, with 3,195 AE reports related to galsulfase identified. The association between galsulfase and AEs was investigated by utilizing four algorithms: reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence propagation neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS). The analysis focused on the timing of onset, signs of AEs, and clinical significance.

Results

Twenty seven organ systems were involved, and significant system organ classes (SOCs) included respiratory, thoracic and mediastinal disorders, and infections and infestations. At the PT level, 72 PTs corresponding to 15 SOCs were identified, with some AEs not previously mentioned in the product label. AEs associated with galsulfase had a median onset time of 1,471 days, with over half of the cases occurred within the first 5 years of treatment initiation.

Conclusion

This investigation delivers an exhaustive and indicative assessment of galsulfase's safety profile, grounded in authentic, real-world evidence. The findings emphasis the importance of continuous safety surveillance and the emergence of new AEs. The identification of previously unreported urologic adverse events, such as glomerulonephritis membranous and nephritic syndrome, warrants further investigation. The study emphasizes the need for enhanced pharmacovigilance to ensure patient safety and the effectiveness of galsulfase treatment.

Long-term cardiovascular outcomes and mortality with enzyme replacement therapy in patients with mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II) is a rare multisystemic lysosomal disorder in which cardiac issues can lead to serious dysfunction and an increased risk of fatal cardiac failure. However, studies on major adverse cardiac event (MACE) outcomes in MPS II are lacking. This study evaluated the cardiovascular outcomes and impact of enzyme replacement therapy (ERT) in patients with MPS II in South Korea. In this national cohort study, utilizing data from the National Health Insurance Database, we evaluated 127 patients with MPS II over a 14-year period to investigate the effects of ERT on MACE and all-cause mortality. We tracked MACE incidence, defined by hospitalizations for cardiovascular events, from diagnosis and adjusted the hazard ratios for MACE using Cox modeling. Over an average follow-up period of 7.3 years, we identified 16 cases of MACE among patients (17.35 per 1000 person-years; 95% confidence interval, 10.74-26.83). Patients receiving ERT exhibited a significantly lower incidence of MACE than untreated patients, with cumulative incidences showing a marked difference of 8.3 years. Notably, initiating ERT at earlier stages post-diagnosis was associated with improved outcomes, underscoring the importance of timely treatment. The key risk factors for MACE included specific arrhythmias, a history of invasive procedures, and depression. Early ERT significantly reduced MACE risk and increased survival in patients with MPS II. This underscores the importance of prompt treatment initiation and comprehensive care to address key risk factors and advocates for an expanded therapeutic strategy to enhance MPS II outcomes.

Safe and effective liver-directed AAV-mediated homology-independent targeted integration in mouse models of inherited diseases

Liver-directed adeno-associated viral (AAV) vector-mediated homology-independent targeted integration (AAV-HITI) by CRISPR-Cas9 at the highly transcribed albumin locus is under investigation to provide sustained transgene expression following neonatal treatment. We show that targeting the 3' end of the albumin locus results in productive integration in about 15% of mouse hepatocytes achieving therapeutic levels of systemic proteins in two mouse models of inherited diseases. We demonstrate that full-length HITI donor DNA is preferentially integrated upon nuclease cleavage and that, despite partial AAV genome integrations in the target locus, no gross chromosomal rearrangements or insertions/deletions at off-target sites are found. In line with this, no evidence of hepatocellular carcinoma is observed within the 1-year follow-up. Finally, AAV-HITI is effective at vector doses considered safe if directly translated to humans providing therapeutic efficacy in the adult liver in addition to newborn. Overall, our data support the development of this liver-directed AAV-based knockin strategy.

Causes of death in mucopolysaccharidoses

Mucopolysaccharidoses are inherited metabolic diseases caused by mutations in genes encoding enzymes required for degradation of glycosaminoglycans. A lack or severe impairment of activity of these enzymes cause accumulation of GAGs which is the primary biochemical defect. Depending on the kind of the deficient enzyme, there are 12 types and subtypes of MPS distinguished. Despite the common primary metabolic deficit (inefficient GAG degradation), the course and symptoms of various MPS types can be different, though majority of the diseases from the group are characterized by severe symptoms and significantly shortened live span. Here, we analysed the frequency of specific, direct causes of death of patients with different MPS types, the subject which was not investigated comprehensively to date. We examined a total of 1317 cases of death among MPS patients, including 393 cases of MPS I, 418 cases of MPS II, 232 cases of MPS III, 45 cases of MPS IV, 208 cases of MPS VI, and 22 cases of MPS VII. Our analyses indicated that the most frequent causes of death differ significantly between MPS types, with cardiovascular and respiratory failures being predominant in MPS I, MPS II, and MPS VI, neurological deficits in MPS III, respiratory issues in MPS IV, and hydrops fetalis in MPS VII. Results of such studies suggest what specific clinical problems should be considered with the highest priority in specific MPS types, apart from attempts to correct the primary causes of the diseases, to improve the quality of life of patients and to prolong their lives.

Characterization of heart disease in mucopolysaccharidosis type II mice

Mucopolysaccharidosis type II (MPSII) is a progressive lysosomal storage disease caused by mutations in the IDS gene, that leads to iduronate 2-sulfatase (IDS) enzyme deficiency. The enzyme catalyzes the first step of degradation of two glycosaminoglycans (GAGs), heparan sulfate (HS) and dermatan sulfate (DS). The consequences of MPSII are progressively harmful and can lead to death by cardiac failure. The aim of this study was to characterize the cardiovascular disease in MPSII mice. Thus, we evaluated the cardiovascular function of MPSII male mice at 6, 8, and 10 months of age, through functional, histological, and biochemical analyzes. Echocardiographic analyses showed a progressive loss in cardiac function, observed through parameters such as reduction in ejection fraction (46% in control versus 28% in MPS II at 10 months, P < .01) and fractional area change (31% versus 23%, P < .05). Similar results were found in parameters of vascular competence, obtained by echo Doppler. Both aortic dilatation and an increase in pulmonary resistance were observed at all time points in MPSII mice. The histological analyses showed an increase in the thickness of the heart valves (2-fold thicker than control values at 10 months). Biochemical analyzes confirmed GAG storage in these tissues, with a massive elevation of DS in the myocardium. Furthermore, an important increase in the activity of proteases such as cathepsin S and B (up to 5-fold control values) was found and could be related to the progressive loss of cardiac function observed in MPSII mice. In this work, we demonstrated that loss of cardiac function in MPSII mice started at 6 months of age, although its global cardiac capacity was still preserved at this time. Disease progressed at later time points leading to heart failure. The MPSII mice at later times reproduce many of the cardiovascular events found in patients with Hunter's disease.

Metabolic Cardiomyopathies and Cardiac Defects in Inherited Disorders of Carbohydrate Metabolism: A Systematic Review

Heart failure (HF) is a progressive chronic disease that remains a primary cause of death worldwide, affecting over 64 million patients. HF can be caused by cardiomyopathies and congenital cardiac defects with monogenic etiology. The number of genes and monogenic disorders linked to development of cardiac defects is constantly growing and includes inherited metabolic disorders (IMDs). Several IMDs affecting various metabolic pathways have been reported presenting cardiomyopathies and cardiac defects. Considering the pivotal role of sugar metabolism in cardiac tissue, including energy production, nucleic acid synthesis and glycosylation, it is not surprising that an increasing number of IMDs linked to carbohydrate metabolism are described with cardiac manifestations. In this systematic review, we offer a comprehensive overview of IMDs linked to carbohydrate metabolism presenting that present with cardiomyopathies, arrhythmogenic disorders and/or structural cardiac defects. We identified 58 IMDs presenting with cardiac complications: 3 defects of sugar/sugar-linked transporters (GLUT3, GLUT10, THTR1); 2 disorders of the pentose phosphate pathway (G6PDH, TALDO); 9 diseases of glycogen metabolism (GAA, GBE1, GDE, GYG1, GYS1, LAMP2, RBCK1, PRKAG2, G6PT1); 29 congenital disorders of glycosylation (ALG3, ALG6, ALG9, ALG12, ATP6V1A, ATP6V1E1, B3GALTL, B3GAT3, COG1, COG7, DOLK, DPM3, FKRP, FKTN, GMPPB, MPDU1, NPL, PGM1, PIGA, PIGL, PIGN, PIGO, PIGT, PIGV, PMM2, POMT1, POMT2, SRD5A3, XYLT2); 15 carbohydrate-linked lysosomal storage diseases (CTSA, GBA1, GLA, GLB1, HEXB, IDUA, IDS, SGSH, NAGLU, HGSNAT, GNS, GALNS, ARSB, GUSB, ARSK). With this systematic review we aim to raise awareness about the cardiac presentations in carbohydrate-linked IMDs and draw attention to carbohydrate-linked pathogenic mechanisms that may underlie cardiac complications.

18-year follow-up of enzyme-replacement therapy in two siblings with attenuated mucopolysaccharidosis I

Mucopolysaccharidosis type I (MPS I) is an autosomal recessive disorder caused by the deficiency of α-L-iduronidase and characterized by a progressive course with multisystem involvement. Clinically, MPS I is divided into two forms: (1) severe (Hurler syndrome), which presents in infancy and is characterized by rapid progressive neurological involvement; (2) attenuated (Hurler/Scheie and Scheie syndromes), which displays a slower progression and absent to mild nervous system involvement. The specific treatment for attenuated MPS I consists of enzyme-replacement therapy with laronidase (human recombinant α-L-iduronidase, Aldurazyme). We present updated data after 18 years of laronidase treatment in two siblings affected by the attenuated form of MPS I who started therapy at 5 months and 5 years of age, respectively. Clinical and laboratory data of the siblings show that long-term enzyme replacement therapy may improve/stabilize many symptoms already present at the time of the diagnosis and reduce the disease progression. This study confirms that early diagnosis and early initiation of enzyme-replacement therapy are essential to modify positively the natural history of the attenuated form of MPS I.