A 10-year follow-up of high-dose ambroxol treatment combined with enzyme replacement therapy for neuropathic Gaucher disease

High-dose ambroxol therapy combined with ERT in patients with neuropathic Gaucher disease.

Rapid home therapy infusion of velaglucerase alfa in naïve patients with Gaucher disease

BACKGROUND

Enzyme replacement therapy (ERT) has revolutionised the management of patients with Gaucher disease (GD). In 2018, we published the safety and efficacy of rapid 10-min infusion of velaglucerase alfa in previously treated patients, mostly on low-dose therapy.

AIM

To improve quality of life (QoL) for patients needing lifelong bi-weekly infusions by introducing a 10-min infusion instead of 1 h per label in patients naive to ERT and on high-dose therapy.

METHODS

Fifteen naive patients were enrolled; all received bi-weekly infusions of 60 units/kgBW velaglucerase alfa; the infusion rate was gradually reduced in the hospital, followed by home infusions. Each infusion was followed for safety. Efficacy parameters were assessed every 3 months. Patient-reported outcome questionnaires were collected at baseline and follow-up.

RESULTS

Ten-minute rapid infusions were well tolerated without related severe adverse events (SAEs). Two patients experienced a non-related SAE and another a possibly related AE. In three patients, the infusion rate was increased to 30 or 60 min (two because of suboptimal response and one because of AE). Two patients dropped out because of an unwillingness to attend follow-up visits during the COVID-19 pandemic. All 13 remaining patients reached the 24-month end-point. The platelet counts increased by a median (range) of 68.38% (12.5-300%) and the lyso-Gb1 levels decreased by 62.6% (32.9-89.9%).

CONCLUSION

Home therapy with rapid infusion of high-dose velaglucerase alfa was a safe, effective and preferable alternative for patients with GD naïve to treatment. We believe that shortening the infusion time improves the QoL of patients with GD who have a lifelong commitment to intravenous therapy.

Cancer Risk in Patients with Gaucher Disease Using Real-World Data

The association between GD and cancer has been uncertain due to ascertainment bias in previously published studies. We analyzed cancer incidence using the Maccabi Healthcare Service (MHS) electronic health records among 264 patients with GD compared to 3440 matched controls. We ascertained cancers diagnosed before and after the index date (i.e., the first documentation of GD in cases and the corresponding date for controls). Before the index date, cancers were diagnosed in 18 individuals, with 11 (4.2%) in the GD group and 7 (0.2%) in the control group. After the index date, cancers were diagnosed in 57 individuals, with 20 (7.9%) in the GD group and 37 (1.1%) in the control group, with a median follow-up of almost 13 years in both groups. The most common cancers diagnosed in GD were non-melanoma skin cancer (NMSC) and hematological malignancies, with a clustering of diagnoses around the time of GD diagnosis. The incidence of cancers (excluding MNSC) was 4.1 (95% CI 2.2-7.1) and 0.7 (95% CI 0.4-0.9) per 1000 patient-years in the GD and control groups, respectively, with an incidence rate ratio of 6.37 (95% CI 3-12.7). Patients with GD underwent more cancer screening tests than their counterparts in the control group. While our study revealed an increased occurrence of cancers in patients with GD, this finding might be partly attributed to the more rigorous surveillance procedures employed in this patient population.

A Deep-Learning Approach to Spleen Volume Estimation in Patients with Gaucher Disease

The enlargement of the liver and spleen (hepatosplenomegaly) is a common manifestation of Gaucher disease (GD). An accurate estimation of the liver and spleen volumes in patients with GD, using imaging tools such as magnetic resonance imaging (MRI), is crucial for the baseline assessment and monitoring of the response to treatment. A commonly used method in clinical practice to estimate the spleen volume is the employment of a formula that uses the measurements of the craniocaudal length, diameter, and thickness of the spleen in MRI. However, the inaccuracy of this formula is significant, which, in turn, emphasizes the need for a more precise and reliable alternative. To this end, we employed deep-learning techniques, to achieve a more accurate spleen segmentation and, subsequently, calculate the resulting spleen volume with higher accuracy on a testing set cohort of 20 patients with GD. Our results indicate that the mean error obtained using the deep-learning approach to spleen volume estimation is 3.6 ± 2.7%, which is significantly lower than the common formula approach, which resulted in a mean error of 13.9 ± 9.6%. These findings suggest that the integration of deep-learning methods into the clinical routine practice for spleen volume calculation could lead to improved diagnostic and monitoring outcomes.

High-Dose Ambroxol Therapy in Type 1 Gaucher Disease Focusing on Patients with Poor Response to Enzyme Replacement Therapy or Substrate Reduction Therapy

Ambroxol hydrochloride (ABX), an oral mucolytic drug available over the counter for many years, acts as a pharmacological chaperone for mutant glucocerebrosidase, albeit at higher doses. Proof-of-concept reports have been published over the past decade on all three types of Gaucher disease (GD). Here, we assess the safety and efficacy of 12 months of 600 mg ambroxol per day in three groups of Type 1 GD patients with a suboptimal response to enzyme replacement therapy (ERT) or substrate reduction therapy (SRT), defined as platelet count < 100 × 10³/L, lumbar spine bone density T-score < -2.0, and/or LysoGb1 > 200 ng/mL, and for a group of naïve patients who had abnormal values in two of these three parameters. We enrolled 40 patients: 28 ERT- or SRT-treated, and 12 naïve. There were no severe adverse effects (AEs). There were 24 dropouts, mostly due to AEs (n = 12), all transient, and COVID-19 (n = 7). Among the 16 completers, 5 (31.2%) had a >20% increase in platelet count, 6 (37.5%) had a >0.2 increase in T-score, and 3 (18.7%) had a >20% decrease in Lyso-Gb1. This study expands the number of patients exposed to high-dose ABX, showing good safety and satisfactory efficacy, and provides an additional rationale for adding off-label ABX to the arsenal of therapies that could be offered to patients with GD1 and a suboptimal response or those unable to receive ERT or SRT.

Contribution of Glucosylsphingosine (Lyso-Gb1) to Treatment Decisions in Patients with Gaucher Disease

Glucosylsphingosine (lyso-Gb1), the deacylated form of glucocerebroside, was shown to be the most specific and sensitive biomarker for diagnosing Gaucher disease (GD). The aim of this study is to assess the contribution of lyso-Gb1 at the time of diagnosis for treatment decisions in naïve patients with GD. Newly diagnosed patients from July 2014 to November 2022 were included in this retrospective cohort study. The diagnosis was done by sending a dry blood spot (DBS) sample for GBA1 molecular sequencing and lyso-Gb1 quantification. Treatment decisions were based on symptoms, signs, and routine laboratory tests. We diagnosed 97 patients (41 males), both type 1 (n = 87), and neuronopathic (n = 10). The median (range) age at diagnosis was 22 (1-78), with 36 children. In 65 patients, GD-specific therapy was started with a median (range) lyso-Gb1, 337 (60-1340) ng/mL, significantly higher than in patients who did not go on to treatment, 153.5 (9-442) ng/mL. Using a receiver operating characteristic (ROC) analysis, a cutoff of lyso-Gb1 > 250 ng/mL was associated with treatment with a sensitivity of 71% and specificity of 87.5%. Predictors of treatment were thrombocytopenia, anemia, and elevated lyso-Gb1 (>250 ng/mL). In conclusion, lyso-Gb1 levels contribute to the medical decision related to the initiation of treatment, mainly among mildly affected newly diagnosed patients. For patients with a severe phenotype, as for all patients, the main value of lyso-Gb1 would be to monitor response to therapy. The variable methodology and differences in the units of lyso-Gb1 measurements between laboratories prevent the adaptation of the exact cut-off we found in general practice. However, the concept is that a significant elevation, i.e., a several-fold increase from the diagnostic lyso-Gb1 cutoff, is related to a more severe phenotype and, accordingly, to the decision regarding the initiation of GD-specific therapy.

Real-Life Experience with Oral Eliglustat in Patients with Gaucher Disease Previously Treated with Enzyme Replacement Therapy

Three types of enzyme replacement therapies (ERTs) and two substrate reduction therapies (SRTs) are approved for symptomatic patients with type 1 Gaucher disease (GD1). Eliglustat is the second SRT approved, yet the first to be approved as first-line therapy for any adult patients with compatible CYP2D6 metabolizer genotype. Herein we report safety and efficacy data of the first 29 patients switched from ERT to eliglustat from the Gaucher Unit at Shaare Zedek Medical Center (SZMC) between 07/2017 and 06/2022; the median (range) time on ERT was 13 (0.66-30) years, and the median (range) time on eliglustat was 7 (1-52) months. Most patients switched due to oral preference or sub-optimal response to low-dose ERT. Twelve patients stopped eliglustat after a median (range) of 4 (1-18) months; 11 due to adverse events (AEs) and one due to personal request. There were no drug-related serious AEs and no drug-related cardiac events. Most AEs were mild and transient, mainly dyspepsia. Efficacy achievements were reflected by maintaining stability. We concluded that switching from ERT to eliglustat is safe if choosing the appropriate patients. Reassuring patients to tolerate early AEs may reduce discontinuation. Following the response and compliance to therapy is important to ensure long-term efficacy.

Platelet Activation and Reactivity in a Large Cohort of Patients with Gaucher Disease

OBJECTIVES

 Patients with Gaucher disease (GD) are at increased risk of bleeding and have varying degrees of thrombocytopenia, making the analysis of platelet function difficult. This study aimed to provide a clinically relevant quantitative assessment of platelet function and determine its relationship with bleeding and GD-related data.

METHODS

 Unstimulated and stimulated platelet function was measured by whole blood flow cytometry of platelet surface-activated αIIbβ3 integrin (detected with monoclonal antibody PAC1), P-selectin (CD62P), and lysosomal-associated membrane protein (LAMP3/CD63) in 149 GD patients.

RESULTS

 GD patients had a higher level of unstimulated CD63 expression than healthy subjects, which was mildly correlated with glucosylsphingosine (lyso-Gb1) levels (r = 0.17, p-value = 0.042). Splenectomized GD patients had a higher level of unstimulated αIIbβ3 integrin and P-selectin expression. Reduced platelet reactivity (-2 standard deviation of reference range) was found in 79 (53%, 95% confidence interval [CI]: 44-61%) patients, of whom 10 (6.7%, 95% CI: 3.3-12%) had more severe platelet dysfunction. In a multivariate model, only lyso-Gb1 levels were associated with the more severe platelet dysfunction. Fifty-four (49%) of 128 adult patients who completed the bleeding tendency questionnaire reported positive bleeding history. In a multivariate logistic model, older age (odds ratio [OR]: 1.05, 95% CI: 1.01-1.1) and low P-selectin reactivity (OR: 2.03, 95% CI: 1.25-3.35) were associated with more than one bleeding manifestation.

CONCLUSION

 Flow cytometry enables the study of platelet function in thrombocytopenic GD patients. A platelet degranulation defect, but not αIIbβ3 integrin activation defect, is associated with clinical bleeding. In vivo increased CD63 expression may be related to GD-related inflammation.

Impact of Long-Term Enzyme Replacement Therapy on Glucosylsphingosine (Lyso-Gb1) Values in Patients with Type 1 Gaucher Disease: Statistical Models for Comparing Three Enzymatic Formulations

For three decades, enzyme replacement therapy (ERT), and more recently, substrate reduction therapy, have been the standard-of-care for type I Gaucher disease (GD1). Since 2012, three different ERTs have been available. No clinical trial or academic study has ever compared these ERTs beyond one year. Herein we compare the impact of the ERTs on repeated measurements of glucosylsphingosine (lyso-Gb1; the most sensitive and GD-specific biomarker). A total of 135 adult patients (77 (57%) female) with GD1, followed from July 2014 to March 2020 and treated with a single ERT (imiglucerase (n = 41, 30.4%), taliglucerase alfa (n = 21, 15.6%) and velaglucerase alfa (n = 73, 54.1%)), were included. Disease severity was defined by genotypes (mild: N370S (c.1226A>G) homozygous and N370S/R496H (c.1604G) compound heterozygous; severe: all other genotypes) and by the severity score index (SSI; mild: <7; severe: ≥7). Lyso-Gb1 testing was performed at Centogene™ on dry blood spot samples collected during routine visits. Patients treated with imiglucerase had higher lyso-Gb1 levels at different time points. A huge variation in lyso-Gb1 levels was noticeable both inter-individually and intra-individually for all three ERTs. A steeper and faster decrease of lyso-Gb1 levels was shown in velaglucerase alfa. Nevertheless, the differences between medications were not very large, and bigger numbers and more pretreatment data are required for more powerful conclusions.

Upgrading the evidence for the use of ambroxol in Gaucher disease and GBA related Parkinson: Investigator initiated registry based on real life data

Ambroxol hydrochloride is an oral mucolytic drug available over-the-counter for many years as cough medicine. In 2009 it was identified as a pharmacological chaperone for mutant glucocerebrosidase, albeit in a several-fold higher dose. Unfortunately, there have been no pharma-driven clinical trials to establish its use. Thus, real-world observational data are needed on the safety and efficacy of ambroxol for patients with Gaucher disease (GD) and GBA-Parkinson disease (GBA-PD). Clinicians treating patients with ambroxol for GD and GBA-PD were approached to collaborate in an investigator-initiated registry. Anonymized data were collected, including demographics, GD type, GD-specific therapy (when applicable), adverse events (AEs), and, when available, efficacy data. We report the data of the first 41 patients (25 females) at a median (range) age 17 (1.5-74) from 13 centers; 11 with GD type 1(four diagnosed with PD), 27 with neuronopathic GD (nGD), and three GBA mutation carriers with PD. The median (range) treatment period and maximum dose of ambroxol were 19 (1-76) months and 435 (75-1485) mg/day, respectively. One patient with type 2 GD died of her disease. No other severe AEs were reported. Twelve patients experienced AE, including minor bowel discomfort, cough, allergic reaction, mild proteinuria, dizziness and disease progression. Clinical benefits were reported in 25 patients, including stable or improved neurological status, increased physical activity, and reduced fatigue. Until the approval of specific therapies for nGD and disease-modification for GBA-PD, these preliminary data may be encouraging to physicians and patients who consider an off-label use of ambroxol.

Patient reported outcome measures in a large cohort of patients with type 1 Gaucher disease

Background

It is now acknowledged that the input of patients in health outcome assessment is vital to understanding the impact of diseases and interventions for those diseases. This study is the first report of patient-reported outcome measures (PROM) in a large cohort of patients with type 1 Gaucher disease (GD1) enabling us to study predictors of the reported outcomes.

Method

The PROM was sent via a mobile phone survey to 405 adult patients with GD1. Demographics, clinical data, and treatment status were extracted from clinic charts. Age, sex, severity score index (SSI) at presentation and treatment status were used as variables to assess outcomes.

Results

A total of 192 patients with GD1 (111 females) responded (47.4% response rate), of whom 124 (64.5%) had received GD1-specific therapy. Around 40% of patients reported that GD had restricted their education/job and fun activities and were concerned about being emotional and financial burdens on others. Concerns regarding the risk of bone disease and Parkinson disease were also high (60%). The severity of GD1 (reflected by the need for GD1-specific therapy and a high SSI) was associated with GD1-related restrictions and concerns, fatigue, physical weakness, bone pain, and worry regarding the future.

Conclusions

The use of GD1 specific PROM highlights personal problems that are not captured by traditional outcome parameters and that need to be addressed to improve health-related quality of life. Validated PROM should be included among the outcome measures in clinical practice and future prospective studies for patients with chronic and rare diseases.