A global neuronopathic gaucher disease registry (GARDIAN): a patient-led initiative

BACKGROUND

Gaucher disease (GD) is a rare autosomal recessive lysosomal storage disorder. GD types 2 and 3 are known as neuronopathic Gaucher disease (nGD) because they have brain involvement that progresses over time. Implementing a systematic approach to the collection of real-world clinical and patient-relevant outcomes data in nGD presents an opportunity to fill critical knowledge gaps and ultimately help healthcare providers in the management of this patient population. This paper summarizes the development of a patient-initiated Gaucher Registry for Development Innovation and Analysis of Neuronopathic Disease (GARDIAN).

METHODS

The International Gaucher Alliance led the GARDIAN planning, including governance, scope, stakeholder involvement, platform, and reporting. Registry element input was determined in a series of meetings with clinical experts, patients, and caregivers, who identified key clinical variables and the draft content of nGD patient-reported outcomes (PRO) and observer-reported outcomes (ObsRO) focusing on symptoms, patient physical and emotional functioning. These were then tested in cognitive interviews with patients with nGD (> 12 years of age) and caregivers.

RESULTS

Core registry data elements (n = 138) were identified by seven global clinical experts from Egypt, Germany, Israel, Japan, United Kingdom (UK), and United State (US) and reviewed via online Delphi method by 14 additional clinicians with experience of nGD from six countries and three pharmaceutical representatives. The elements were consistent with those identified via interviews with 10 patients/caregivers with nGD from Japan, Sweden, UK, and US. Key domains identified were demographics, diagnostic information, health status, clinical symptomatology, laboratory testing, treatment, healthcare resource utilization, aids/home improvements, and patient/caregiver burden and quality of life, specifically physical functioning, self-care, daily and social activities, emotional impacts, support services, and caregiver-specific impacts. Nine caregivers and six patients from the US, UK, China, Mexico, Egypt, and Japan participated in the cognitive interviews that informed revisions to ensure that all items are understandable and interpreted as intended.

CONCLUSIONS

The comprehensive set of clinical and patient relevant outcomes data, developed collaboratively among all stakeholders, to be reported using GARDIAN will bridge the many gaps in the understanding of nGD and align with regulatory frameworks on real-world data needs.

FindZebra online search delving into rare disease case reports using natural language processing

Early diagnosis is crucial for well-being and life quality of the rare disease patient. Access to the most complete knowledge about diseases through intelligent user interfaces can play an important role in supporting the physician reaching the correct diagnosis. Case reports may offer information about heterogeneous phenotypes which often further complicate rare disease diagnosis. The rare disease search engine FindZebra.com is extended to also access case report abstracts extracted from PubMed for several diseases. A search index for each disease is built in Apache Solr adding age, sex and clinical features extracted using text segmentation to enhance the specificity of search. Clinical experts performed retrospective validation of the search engine, utilising real-world Outcomes Survey data on Gaucher and Fabry patients. Medical experts evaluated the search results as being clinically relevant for the Fabry patients and less clinically relevant for the Gaucher patients. The shortcomings for Gaucher patients mainly reflect a mismatch between the current understanding and treatment of the disease and how it is reported in PubMed, notably in the older case reports. In response to this observation, a filter for the publication date was added in the final version of the tool available from deep.findzebra.com/<disease> with <disease> = gaucher, fabry, hae (Hereditary angioedema).

Development and validation of Gaucher disease type 1 (GD1)-specific patient-reported outcome measures (PROMs) for clinical monitoring and for clinical trials

BACKGROUND

Disease-specific patient-reported outcome measures (PROMs) are fundamental to understanding the impact on, and expectations of, patients with genetic disorders, and can facilitate constructive and educated conversations about treatments and outcomes. However, generic PROMs may fail to capture disease-specific concerns. Here we report the development and validation of a Gaucher disease (GD)-specific PROM for patients with type 1 Gaucher disease (GD1) a lysosomal storage disorder characterized by hepatosplenomegaly, thrombocytopenia, anemia, bruising, bone disease, and fatigue.

RESULTS AND DISCUSSION

The questionnaire was initially developed with input from 85 patients or parents of patients with GD1 or GD3 in Israel. Owing to few participating patients with GD3, content validity was assessed for patients with GD1 only. Content validity of the revised questionnaire was assessed in 33 patients in the US, France, and Israel according to US Food and Drug Administration standards, with input from a panel of six GD experts and one patient advocate representative. Concept elicitation interviews explored patient experience of symptoms and treatments, and a cognitive debriefing exercise explored patients' understanding and relevance of instructions, items, response scales, and recall period. Two versions of the questionnaire were subsequently developed: a 24-item version for routine monitoring in clinical practice (rmGD1-PROM), and a 17-item version for use in clinical trials (ctGD1-PROM). Psychometric validation of the ctGD1-PROM was assessed in 46 adult patients with GD1 and re-administered two weeks later to examine test-retest reliability. Findings from the psychometric validation study revealed excellent internal consistency and strong evidence of convergent validity of the ctGD1-PROM based on correlations with the 36-item Short Form Health Survey. Most items were found to show moderate, good, or excellent test-retest reliability.

CONCLUSIONS

Development of the ctGD1-PROM represents an important step forward for researchers measuring the impact of GD and its respective treatment.

Impact of the COVID-19 pandemic on the standard of care for patients with lysosomal storage diseases: A survey of healthcare professionals in the Fabry, Gaucher, and Hunter Outcome Survey registries

The impact of the COVID-19 pandemic on the standards of care of patients with lysosomal storage diseases and the needs of their healthcare providers were explored using a 12-question survey. Overall, 80/91 respondents (88%) indicated that the pandemic had negatively affected standards of care. With increased reliance on telemedicine, the respondents highlighted the need for a personalized approach to care, direct and frequent communication with patients, and greater involvement of patients and caregivers.

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The COVID-19 pandemic has changed how physicians and patients interact.

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A survey explored the impact of these changes on the care of patients with lysosomal storage diseases.

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88% of respondents noted that the pandemic had affected standards of care.

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Increased need for personalized care and direct communication was noted.

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Increased reliance on telemedicine was also highlighted.

Plasma adiponectin is a potential biomarker for organ involvement in male Fabry disease patients

Fabry disease is an X-linked lysosomal storage disorder caused by pathogenic variants in GLA. It manifests in hemizygous males and in many heterozygous females. Cardiovascular and renal involvement are frequent. Adiponectin is a circulating hormone that has been linked to numerous disease conditions including heart and kidney failure. In the present pilot study, we investigated plasma adiponectin levels in a cohort of 56 individuals with a genetic diagnosis of Fabry disease. Adiponectin levels did not differ between patients and controls. However, in male patients, significantly decreased adiponectin levels were associated with cardiovascular manifestation, while increased levels were associated with renal involvement. Similar trends in female patients did not reach statistical significance. Lyso-Gb3, a metabolite with good diagnostic/screening performance, was not indicative of organ involvement. In combination, adiponectin and Lyso-Gb3 may be of value for identification and stratification of Fabry patients. A potential additional relevance for prognosis and monitoring should be addressed by future studies in larger cohorts.

Demographics and patient characteristics of 1209 patients with Gaucher disease: Descriptive analysis from the Gaucher Outcome Survey (GOS)

The Gaucher Outcome Survey (GOS) is an international Gaucher disease (GD) registry established in 2010 for patients with a confirmed GD diagnosis, regardless of GD type or treatment status, designed to evaluate the safety and long‐term effectiveness of velaglucerase alfa and other GD‐related treatments. As of February 25, 2017, 1209 patients had enrolled, the majority from Israel (44.3%) and the US (31.4%). Median age at GOS entry was 40.4 years, 44.1% were male, and 13.3% had undergone a total splenectomy. Most patients had type 1 GD (91.5%) and were of Ashkenazi Jewish ethnicity (55.8%). N370S/N370S was the most prevalent genotype, accounting for 44.2% of genotype‐confirmed individuals (n = 847); however, there was considerable variation between countries. A total of 887 (73.4%) patients had received ≥1 GD‐specific treatment at any time, most commonly imiglucerase (n = 587), velaglucerase alfa (n = 507), and alglucerase (n = 102). Hematological and visceral findings at the time of GOS entry were close to normal for most patients, probably a result of previous treatment; however, spleen volume of patients in Israel was almost double that of patients elsewhere (7.2 multiples of normal [MN] vs. 2.7, 2.9 and 4.9 MN in the US, UK and rest of world), which may be explained by a greater disease severity in this cohort. This analysis aimed to provide an overview of GOS and present baseline demographic and disease characteristics of participating patients to help improve the understanding of the natural history of GD and inform the overall management of patients with the disease.

Impaired platelet function and peripartum bleeding in women with Gaucher disease

The risk of bleeding during delivery may be increased in women with Gaucher disease. We aimed to evaluate potential predictors for peripartum haemorrhage (PPH) during childbirth in these patients, while focusing upon coagulation tests and platelet function assays. Women with type 1 Gaucher disease who gave birth at Sheba Medical Center between 1999–2009 comprised the study cohort. Data collected included disease history, enzyme treatment, platelet counts, delivery and pregnancy outcome. PPH was defined as excessive bleeding during or immediately following delivery. Coagulation studies and platelet function tests, including aggregometry and cone and platelet (CPA) analyses, were performed on all women. We compared women with PPH (bleeders) and non-bleeders. Furthermore, women with abnormal CPA platelet function tests were compared with those with normal CPA platelet function with regards to the risk for PPH in at least one pregnancy. Forty-five pregnancies of 20 women were studied. Six women received enzyme replacement therapy during pregnancy. Mean platelet count prior to delivery was 83,000/μl ± 35,000/μl. Fourteen out of 45 (31%) deliveries were complicated by PPH. Neither thrombocytopenia nor enzyme therapy predicted PPH. Twelve out of 13 women with PPH (92.3%) versus 2/7 non-bleeders (28.6%) had impaired platelet aggregation (less than the 3rd percentile of normal average aggregate size values), when tested by CPA, (odds ratio [OR] 17.8, 95% confidence interval [CI] 2.5; 126.2; p=0.007). Notably, 78.6% of women with impaired CPA aggregation developed PPH during at least one delivery, as opposed to 16.7% of those with normal CPA platelet function tests (OR 11.6, 95% CI 1.7–77.7, p=0.018). In conclusion, women with type 1 Gaucher disease who have abnormal platelet function tests may have an increased risk of PPH.

Exploring the patient journey to diagnosis of Gaucher disease from the perspective of 212 patients with Gaucher disease and 16 Gaucher expert physicians

Gaucher disease (GD) is a rare hereditary disorder caused by a deficiency of the lysosomal enzyme β-glucocerebrosidase. Diagnosis is challenging owing to a wide variability in clinical manifestations and severity of symptoms. Many patients may experience marked delays in obtaining a definitive diagnosis. The two surveys reported herein aimed to explore the patient journey to diagnosis of GD from the perspectives of Gaucher expert physicians and patients. Findings from the surveys revealed that many patients experienced diagnostic delays and misdiagnoses, with nearly 1 in 6 patients stating that they were not diagnosed with GD for 7years or more after first consulting a doctor. Physicians and patients both reported multiple referrals to different specialties before a diagnosis of GD was obtained, with primary care, haematology/haematology-oncology and paediatrics the main specialties to which patients first presented. Splenomegaly, thrombocytopenia, anaemia and bone pain were reported as the most common medical problems at first presentation in both surveys. These findings support a clear need for straightforward and easy-to-follow guidance designed to assist non-specialists to identify earlier patients who are at risk of GD.

Reductions in glucosylsphingosine (lyso-Gb1) in treatment-naïve and previously treated patients receiving velaglucerase alfa for type 1 Gaucher disease: Data from phase 3 clinical trials

Gaucher disease (GD), an autosomal recessive lipid storage disorder, arises from mutations in the GBA1 (β-glucocerebrosidase) gene, resulting in glucosylceramide accumulation in tissue macrophages. Lyso-Gb1 (glucosylsphingosine, lyso-GL1), a downstream metabolic product of glucosylceramide, has been identified as a promising biomarker for the diagnosis and monitoring of patients with GD. This retrospective, exploratory analysis of data from phase 3 clinical trials of velaglucerase alfa in patients with type 1 GD evaluated the potential of lyso-Gb1 as a specific and sensitive biomarker for GD. A total of 22 treatment-naïve patients and 21 patients previously treated with imiglucerase (switch patients) were included in the analysis. Overall, demographics between the two groups were similar. Mean lyso-Gb1 concentrations were reduced by 302.2ng/mL from baseline to week 209 in treatment-naïve patients and by 57.3ng/mL from baseline to week 161 in switch patients, corresponding to relative reductions of 82.7% and 52.0%, respectively. In both the treatment-naïve and switch groups, baseline mean lyso-Gb1 was higher for patients with at least one N370S mutation (363.9ng/mL and 90.7ng/mL, respectively) than for patients with non-N370S mutations (184.6ng/mL and 28.3ng/mL, respectively). Moderate correlations between decreasing lyso-Gb1 levels and increasing platelet counts, and with decreasing spleen volumes, were observed at some time points in the treatment-naïve group but not in the switch group. These findings support the utility of lyso-Gb1 as a sensitive and reliable biomarker for GD, and suggest that quantitation of this biomarker could serve as an indicator of disease burden and response to treatment.

Home infusion of intravenous velaglucerase alfa: Experience from pooled clinical studies in 104 patients with type 1 Gaucher disease

The introduction of a home therapy option during clinical trials of velaglucerase alfa in patients with type 1 Gaucher disease marked the first time that home infusions have been permitted during a clinical trial for an investigational drug for Gaucher disease. Home infusions were an available option in 4 open-label velaglucerase alfa clinical studies to eligible patients who received their initial infusions at a clinic. Patients who participated in the home therapy option and received at least 10% of their infusions at home (n=100) received a range of 11.6%-100% of their scheduled infusions at home (median 87.5%), excluding infusions received at the clinic during protocol-mandated visits. The length of time over which individual patients received home therapy ranged from 13days to 4.56years (median 0.57years). During the time that home therapy was available, 2904 of 3572 (81.3%) infusions were administered at home. Ten patients experienced 62 infusion-related adverse events (IRAEs) during 38 home infusions, with malaise, pain, hypertension, fatigue, and headache being reported most frequently. No notable differences were found between the type and severity of IRAEs experienced at home and those experienced at the clinic. Home infusions administered by trained and qualified medical personnel were successfully introduced into the velaglucerase alfa clinical development program, and fewer than 10% of patients experienced IRAEs in the home setting. Local labeling and practice guidelines should be consulted for administration of velaglucerase alfa infusions at home.

Children with type 1 Gaucher disease: Changing profiles in the 21st century

Gaucher disease (GD) has phenotypic variability. Increased GD awareness especially among at-risk Ashkenazi Jews (AJ) and availability of non-invasive diagnosis induced trend to prenatal screening. We retrospectively assessed pediatric (<16years) Israeli AJ GD patients to ascertain demographics and phenotype at presentation and over-time because many were identified by large-scale screening. 55/67 patients born since 01/01/2000 are AJ with non-neuronopathic GD: 28 (50.9%) are N370S/N370S; 24 (43.6%) are N370S/other; 3 (3.5%) have no N370S allele. 30 (54.5%) diagnosed by screening; 10 (18.2%) with sibling diagnosed by screening. Of 19 (34.5%) receiving enzyme replacement therapy (ERT), 4/19 (21.1%) were by screening (N370S/N370S; N370S/L444P, N370S/84GG, N370S/IVS2+1); 15/19 (78.9%) diagnosed by symptoms and/or symptomatic sibling. 4/19 (21.1%) began ERT at age <2years; 9/19 (47.4%) at 3-5years; 6/19 (31.6%) at 6-12years. 49% presented with height/weight growth percentiles ≤25%, but group means were comparable up to 12years follow-up including 10 receiving ERT (8 for >5years). 22% presented with anemia, 20% with thrombocytopenia; at last follow-up 4% and 6%, respectively, remained cytopenic. We present a new demographic profile for pediatric GD because many identified by screening had/have few GD signs/symptoms. Nonetheless, early diagnosis is important, especially for non-N370S, non-mild genotypes.

Comparison of Bone Mineral Density by Dual-Energy X-Ray Absorptiometry and Bone Strength by Speed-of-Sound Ultrasonography in Adults With Gaucher Disease

Patients with the lysosomal disorder Gaucher disease (GD) are at risk of osteoporosis and/or avascular necrosis, but to date, no adequate biomarkers are available to ascertain individual predilections. Bone mineral density by dual-energy X-ray absorptiometry (DXA) has traditionally been used to monitor trends. With the availability of a speed-of-sound (SOS) ultrasonography to assess bone strength/elasticity, we aimed to ascertain whether these modalities are complimentary or comparable so SOS, with no radiation risk, might be used more routinely as a potential biomarker. A prospective comparative study in adult GD patients undergoing routine follow-up of bone mineral density T- and Z-scores at forearm (FA), femoral neck, and lumbar spine, and SOS Z-scores at FA was initiated. Interpretation was by qualitative categorization of Z-scores. The kappa measure of agreement beyond chance was calculated between pairs of measurements and the McNemar test was then applied. This noninterventional trial (ClinicalTrials.gov Identifier: NCT02067247) was approved by the institutional ethics committee. There were 89 patients (ages 21-78 years, 61% female, 62% common Ashkenazi genotype, 18% splenectomized, and 18% with avascular necrosis/fractures). When comparing Z-scores at FA by DXA and SOS, only 39.3% correlated, while the remaining results were in disagreement; no trend was noted. Similarly, when comparing Z-scores at the femoral neck by DXA with those at FA by SOS, 44.9% of the results were in agreement; no trend was noted; and Z-scores at the lumbar spine by DXA with FA by SOS, 46% were in agreement and no trend was noted. DXA at the 3 sites did not track in the same direction or the same magnitude of difference with SOS at FA in adult patients with GD. Due to the fundamental differences between the 2 measurements and their clinical correlates, plus the lack of long-term follow-up to assess outcome, the potential added value of the measurements at the FA by SOS in patients with GD awaits further studies.

Color Discrimination in Patients with Gaucher Disease and Parkinson Disease

BACKGROUND

Poor color discrimination among patients with Parkinson disease (PD) has long been recognized. It has been shown that carrying one or two mutations in the β-glucocerebrosidase gene (GBA) for the autosomal disease Gaucher disease (GD), as based initially on clinical evidence, is a genetic risk factor for early-onset PD.

OBJECTIVE

The purpose of this study was to assess color discrimination in patients with one or two GBA mutations relative to healthy controls to ascertain whether this function is affected when persons with GD or even one GBA mutation develop PD.

METHODS

The Farnsworth-Munsell 100 hue test (FMHT) was evaluated among patients with GD+PD compared to patients with GD only, obligate GBA carriers with and without PD, patients with PD only, and healthy controls. FMHT outcome include computer-generated TES (Total Error Score) and values recommended by Vingrys & King-Smith.

RESULTS

Six groups of 10 persons were tested. Significant differences were seen for male GD+PD and for age in PD. The highest mean TES was in the PD only group, the lowest in the GD only group. There was a significant difference because of PD in groups with GD and GBA carriers. GD+PD means were between GD only and PD only mean scores.

CONCLUSIONS

These findings confirm that PD impacts color discrimination, more in males with GD+PD but nonetheless, GD+PD patients (but not GBA carriers) had better scores than PD only patients.

Thromboelastography as a Surrogate Marker of Perisurgical Hemostasis in Gaucher Disease

Thromboelastography (TEG) has long been available for routine monitoring of perisurgical and postpartum hemostasis, especially at point of care. The purpose of this study is to retrospectively compare TEG parameters to concomitant standard clotting test results in an unselected cohort of patients with Gaucher disease to ascertain whether TEG values are specific and sensitive enough to substitute for classic coagulation tests for decision making. This remains a cogent concern because of high incidence of thrombocytopenia in patients with Gaucher disease. Thromboelastography values were compared to concomitant platelet counts, partial thromboplastin time, international normalization ratio, and plasma fibrinogen. Demographic characteristics were collected from patients’ files. There were 22 patients with Gaucher disease (2 children; 12.5%) for whom there were 24 TEG results at the same time as classic coagulation test results and 30% performed platelet function tests. The current study shows linear and/or monotonic relationships between platelet counts and several TEG values that were significant over a range of platelet counts including severe thrombocytopenia. The fibrinogen component, correlating only with the rate of clot lysis, played a lesser role. Based on these preliminary results albeit in a small cohort with only 1 case of hemorrhage, there is putative support for the intention to treat patients with Gaucher disease based on TEG results using the same TEG protocol as for other patients undergoing comparable procedures in our institution.

13,845 home therapy infusions with velaglucerase alfa exemplify safety of velaglucerase alfa and increased compliance to every-other-week intravenous enzyme replacement therapy for Gaucher disease

BACKGROUND

Lifelong intravenous (IV) enzyme replacement therapy (ERT) every other week for Gaucher disease is appreciated as decreasing quality of life in a palpable way.

OBJECTIVE

To review the Israeli experience with the home therapy option for IV velaglucerase alfa (Shire, Lexington MA USA) infusions every-other-week in the clinical trial context, in the early access program (EAP) during a shortage with the standard commercial ERT, and currently with the commercially available drug (VPRIV, Shire).

RESULTS

Among 24 patients participating in trials, 1654 infusions were at home; in the EAP and commercial setting, 12,191 infusions were performed at home for a total of 154 patients with 98.4% compliance. There were no incidents of serious adverse events.

CONCLUSION

This is the first review of experience of 174 patients and 13,845 intravenous infusions of velaglucerase alfa for Gaucher in the home setting, underscoring its safety.

Proof-of-principle rapid noninvasive prenatal diagnosis of autosomal recessive founder mutations

BACKGROUND

Noninvasive prenatal testing can be used to accurately detect chromosomal aneuploidies in circulating fetal DNA; however, the necessity of parental haplotype construction is a primary drawback to noninvasive prenatal diagnosis (NIPD) of monogenic disease. Family-specific haplotype assembly is essential for accurate diagnosis of minuscule amounts of circulating cell-free fetal DNA; however, current haplotyping techniques are too time-consuming and laborious to be carried out within the limited time constraints of prenatal testing, hampering practical application of NIPD in the clinic. Here, we have addressed this pitfall and devised a universal strategy for rapid NIPD of a prevalent mutation in the Ashkenazi Jewish (AJ) population.

METHODS

Pregnant AJ couples, carrying mutation(s) in GBA, which encodes acid β-glucosidase, were recruited at the SZMC Gaucher Clinic. Targeted next-generation sequencing of GBA-flanking SNPs was performed on peripheral blood samples from each couple, relevant mutation carrier family members, and unrelated individuals who are homozygotes for an AJ founder mutation. Allele-specific haplotypes were constructed based on linkage, and a consensus Gaucher disease-associated founder mutation-flanking haplotype was fine mapped. Together, these haplotypes were used for NIPD. All test results were validated by conventional prenatal or postnatal diagnostic methods.

RESULTS

Ten parental alleles in eight unrelated fetuses were diagnosed successfully based on the noninvasive method developed in this study. The consensus mutation-flanking haplotype aided diagnosis for 6 of 9 founder mutation alleles.

CONCLUSIONS

The founder NIPD method developed and described here is rapid, economical, and readily adaptable for prenatal testing of prevalent autosomal recessive disease-causing mutations in an assortment of worldwide populations.

FUNDING

SZMC, Protalix Biotherapeutics Inc., and Centogene AG.

Seven-year safety and efficacy with velaglucerase alfa for treatment-naïve adult patients with type 1 Gaucher disease

Velaglucerase alfa is a human β‐glucocerebrosidase approved for Gaucher disease type 1 (GD1) treatment. This report summarizes the 7‐year experience of the now‐completed phase I/II and extension studies of adult GD1 patients who received velaglucerase alfa. Ten patients who completed the 9‐month, phase I/II study entered the extension trial TKT025EXT, of which eight completed this study. Doses were reduced after a cumulative treatment period of 15 to 18 months. Although all patients experienced ≥1 adverse event, no patient withdrew due to a drug‐related adverse event or required premedication. No patient developed anti‐drug antibodies, compliance remained high (median 98%), and seven of eight eligible patients transitioned to home infusions under supervision by healthcare professionals. Statistically significant improvements were observed for efficacy parameters: mean percentage changes from baseline (95% confidence intervals) were 18% (12%, 24%) for hemoglobin concentration, 115% (66%, 164%) for platelet counts, and −42% (−53%, −31%) and −78% (−94%, −62%) for liver and spleen volumes, respectively. Improvements were also observed for secondary endpoints chitotriosidase and CCL18 levels and exploratory endpoints (bone mineral density [BMD], bone marrow burden [BMB] scores). Normalization to near‐normalization of individuals' hemoglobin concentrations, platelet counts, liver volumes, and BMB scores was observed, and there were marked improvements in spleen volumes, biomarkers, and BMD. TKT025EXT represents the longest, prospective clinical trial for GD1 treatment to date and suggests that, despite dose reduction within 18 months of initiating therapy, velaglucerase alfa was generally well tolerated and was associated with marked improvement, including near normalization and/or normalization of key GD1 disease parameters. Am. J. Hematol. 90:577–583, 2015. © 2015 The Authors. American Journal of Hematology published by Wiley Periodicals, Inc.

Velaglucerase alfa (VPRIV) enzyme replacement therapy in patients with Gaucher disease: Long-term data from phase III clinical trials

Type 1 Gaucher disease is an inherited lysosomal enzyme deficiency with variable age of symptom onset. Common presenting signs include thrombocytopenia, anemia, hepatosplenomegaly, bone abnormalities, and, additionally in children, growth failure. Fifty-seven patients aged 3–62 years at the baseline of two phase III trials for velaglucerase alfa treatment were enrolled in the single extension study. In the extension, they received every-other-week velaglucerase alfa intravenous infusions for 1.2–4.8 years at 60 U/kg, although 10 patients experienced dose reduction. No patient experienced a drug-related serious adverse event or withdrew due to an adverse event. One patient died following a convulsion that was reported as unrelated to the study drug. Only one patient tested positive for anti-velaglucerase alfa antibodies. Combining the experience of the initial phase III trials and the extension study, significant improvements were observed in the first 24 months from baseline in hematology variables, organ volumes, plasma biomarkers, and, in adults, the lumbar spine bone mineral density Z-score. Improvements were maintained over longer-term treatment. Velaglucerase alfa had a good long-term safety and tolerability profile, and patients continued to respond clinically, which is consistent with the results of the extension study to the phase I/II trial of velaglucerase alfa. EudraCT number 2008-001965-27; http://www.clinicaltrials.gov identifier NCT00635427. Am. J. Hematol. 90:584–591, 2015. © 2015 Wiley Periodicals, Inc.

Safety and efficacy results of switch from imiglucerase to velaglucerase alfa treatment in patients with type 1 Gaucher disease

Gaucher disease (GD) is a lysosomal storage disorder; symptomatic patients with type 1 GD need long-term disease-specific therapy of which the standard of care has been enzyme replacement therapy (ERT). Thirty-eight of 40 patients (aged 9-71 years) clinically stable on ERT with imiglucerase, safely switched to a comparable dose of velaglucerase alfa (units/kg) during TKT034, a 12-month, open-label clinical study, and for 10-50 months in an extension study. The most common adverse events (AEs) judged to be drug-related in the extension were fatigue and bone pain. No drug-related serious AEs were reported. No AEs led to study withdrawal. At 24 months from baseline (baseline being TKT034 week 0), patients had generally stable hemoglobin, platelet, spleen, liver, and bone density parameters. Nevertheless, dose adjustment based on the achievement of therapeutic goals was permitted, and 10 patients, including seven patients who had platelet counts <100 × 10(9) /L at baseline, were given at least one 15 U/kg-dose increase during the extension. Trends indicative of improvement in platelet count and spleen volume, and decreasing levels of GD biomarkers, chitotriosidase and CCL18, were observed. Immunogenicity was seen in one patient positive for anti-imiglucerase antibodies at baseline. This patient tested positive for anti-velaglucerase alfa antibodies in TKT034, with low antibody concentrations, and throughout the extension study; however, the patient continued to receive velaglucerase alfa without clinical deterioration. In conclusion, clinically stable patients can be switched from imiglucerase to velaglucerase alfa ERT and maintain or achieve good therapeutic outcomes.

Effect of cyclic, low dose pyrimethamine treatment in patients with Late Onset Tay Sachs: an open label, extended pilot study

BACKGROUND

Late Onset Tay- Sachs disease (LOTS) is a rare neurodegenerative lysosomal storage disease which results from mutations in the gene encoding the α subunit (HEXA) of β-hexosaminidase enzyme (HexA). At the present time, no effective treatment exists for LOTS and other neurodegenerative diseases involving the central nerve system (CNS). Pyrimethamine (PMT) was previously shown to act as a HexA chaperone in human fibroblasts in vitro carrying some (e.g., αG269S), but not all LOTS-related mutations. The present study assessed the effect of cyclic, low dose and long term pyrimethamine treatment on HexA in subjects with LOTS.

METHODS

In an open label trial in 4 LOTS patients, PMT was initiated at an average daily dose of ~2.7 mg and administered cyclically guided by blood lymphocyte HexA activity for a mean duration of 82.8 (±22.5; SD) weeks (~1.5 year).

RESULTS

HexA activity rose in all subjects, with a mean peak increase of 2.24 folds (±0.52; SD) over baseline activity (range 1.87-3). The mean treatment time required to attain this peak was of 15.7 (±4.8; SD) weeks. Following increase in activity, HexA gradually declined with the continued use of PMT, which was then stopped, resulting in the return of HexA activity to baseline. A second cycle of PMT treatment was then initiated, resulting again in an increase in HexA activity. Three of the patients experienced a measurable neuropsychiatric deterioration whereas one subject remained entirely stable.

CONCLUSIONS

Cyclic low dose of PMT can increase HexA activity in LOTS patients. However, the observed increase is repeatedly transient and not associated with discernible beneficial neurological or psychiatric effects.

The emergence of Parkinson disease among patients with Gaucher disease

In the last decade, several lines of evidence have been presented that document the clinical manifestations, genetic associations, and sub-cellular mechanisms of the inter-relatedness of β-glucocerebrosidase mutations and the emergence of Parkinson disease among carriers and patients with Gaucher disease. This review is an attempt to apprise the reader of the recent literature with the caveat that this is an area of intensive exploration that is constantly being updated because of the immediate clinical ramifications but also because of the impact on our understanding of Parkinson disease, and finally because of the unexpected inter-reactions between these entities on the molecular level. It has been an unexpected happenstance that it has been discovered that a rare monogenetic disease has an interface at many points with a neurological disorder of the elderly that has both familial and sporadic forms: to date there is no cure for either of these disorders.

Safety and efficacy of two dose levels of taliglucerase alfa in pediatric patients with Gaucher disease

Taliglucerase alfa is a plant cell-expressed beta-glucocerebrosidase approved in the United States, Israel, Australia, Canada, and other countries for enzyme replacement therapy in adults with Type 1 Gaucher disease (GD), for treatment of pediatric patients in the United States, Australia, and Canada, and for the hematologic manifestations of Type 3 GD in pediatric patients in Canada. This multicenter, randomized, double-blind, parallel-dose, 12-month study assessed efficacy and safety of taliglucerase alfa in pediatric patients with GD. Eleven children were randomized to taliglucerase alfa 30U/kg (n=6) or 60U/kg (n=5) per infusion every other week. From baseline to month 12, the following changes were noted in the taliglucerase alfa 30-U/kg and 60-U/kg dose groups, respectively: median hemoglobin concentrations increased by 12.2% and 14.2%; the interquartile ranges of median percent change in hemoglobin levels from baseline were 20.6 and 10.4, respectively; mean spleen volume decreased from 22.2 to 14.0 multiples of normal (MN) and from 29.4 to 12.9 MN; mean liver volume decreased from 1.8 to 1.5 MN and from 2.2 to 1.7 MN; platelet counts increased by 30.9% and 73.7%; and chitotriosidase activity was reduced by 58.5% and 66.1%. Nearly all adverse events were mild/moderate, unrelated to treatment, and transient. One patient presented with treatment-related gastroenteritis reported as a serious adverse event due to the need for hospitalization for rehydration. No patient discontinued. These data suggest that taliglucerase alfa has the potential to be a therapeutic treatment option for children with GD. This study was registered at www.clinicaltrials.gov as NCT01132690.

Management of Gaucher disease: enzyme replacement therapy

Starting in 1994, 3 years after the first approval of the placental-derived enzyme replacement therapy (ERT) with alglucerase, the recombinant form imiglucerase was the introduced and became the standard of care for the visceral symptoms of Gaucher disease. For patients with non-neuronopathic (type 1) Gaucher disease, ERT is safe, with few adverse/side events, and effective in reducing hepatosplenomegaly, improving hematological parameters such as anemia and thrombocytopenia, and to a lesser degree, ameliorating lung- and bone-referred disease. Dosage differences are appreciated mainly as differences in the initial slope in achieving improvements before plateauing. Because ERT does not pass the blood-brain barrier, for patients with the acute neuronopathic form (type 2), there is no substantial change in the life-threatening neurological parameters and hence ERT is not seen as efficacious; but for patients with sub-acute neuronopathic forms (type 3), ERT for the often devastating visceral symptoms, improved quality of life, and longevity make ERT part of the standard care. Due to a world-wide reduction in imiglucerase availability mid-2009 that was not resolved quickly, patients were ERT-stopped or dose-reduced, re-invigorated the movement to provide additional therapeutic options. Early access programs of two new ERTs, then at the pre-license stage, were initiated at regulatory authorities' request for patients requiring ERT. At that point, velaglucerase alfa which has the native-enzyme sequence produced in a (proprietary) human cell line, and taliglucerase alfa, which is plant-cell-derived and produced in an inexpensive platform, were completing Phase 3 clinical trials. Velaglucerase alfa was FDA-approved in February 2010 while taliglucerase alfo was approved in May 2012. Marketing of these ERTs has also targeted the extraordinarily high cost of imiglucerase. However, with > 20 years' experience with infusible ERTs, many patients are eager to consider oral options including substrate reduction and/or pharmacological chaperone treatments taken as pills or possibly oral formulations of an ERT

α-Synuclein rs356219 polymorphisms in patients with Gaucher disease and Parkinson disease

Mutations in β-glucocerebrosidase, the genetic defect in Gaucher disease (GD), are an important susceptibility factor for Parkinson disease (PD). A PD effector is α-synuclein (SNCA) hypothesized to selectively interact with β-glucocerebrosidase under lysosomal conditions. SNCA polymorphism rs356219 may be associated with early-age-onset PD, common among patients with GD+PD. The objective of this study was to ascertain rs356219 genotypes of GD+PD patients. All GD+PD patients at our Gaucher referral clinic were asked to participate. A GD-only sex-, age-, GD genotype-, and enzyme therapy (ERT)-matched control was found for each GD+PD participant. Student's t-test was used (p-value <0.05 as significant). There were 14 GD+PD patients: all Ashkenazi Jewish; 11 males (78.6%); mean (range) age diagnosed GD 34.2 (5-62) years; 50% N370S homozygous; mild to moderate GD; 3 asplenic and only these have osteonecrosis; 5 received ERT; mean age (range) diagnosed PD was 57.8 (43-70) years; first PD sign was tremor in 9 (64.3%); cognitive dysfunction in all. In GD+PD, frequency for AG+GG (9) was greater than AA (5); in GD only, there was equality (7). Odds Ratio risk for PD increases with number minor alleles: but not significantly greater among GD+PD than GD only; in aggregate, there was no difference between cohorts for frequency of minor alleles. The limitation of this study is few GD+PD, albeit virtually all the GD+PD cohort >500 adult GD patients in our clinic. Nonetheless, as a foray into potential genetic GD susceptibility for a synucleinopathy, this study suggests the need for collaboration to achieve larger sample size.

An intronic haplotype in α galactosidase A is associated with reduced mRNA expression in males with cryptogenic stroke

Persons with unexplained early-onset stroke have been targeted for screening surveys for Fabry disease, the most common of the three X-linked lysosomal disorders, because Fabry patients with stroke are more likely to have the life-threatening progressive cardiac and renal manifestations and would therefore most benefit from early diagnosis and intervention with enzyme replacement therapy (ERT). Among 175 Israeli patients with unexplained cryptogenic stroke screened for mutations in the Fabry α galactosidase A (GLA) gene, sequencing identified six with 2-4 GLA intronic variants, one of whose father and three sisters had the same variants. Two variants, c.640-16A>G (g.10115A>G) in intron 4 and c.1000-22C>T (g.10956C>T) in intron 6, were common to all patients. However, three males with a common four variant intronic haplotype had low residual enzyme activity and ~50% reduced mRNA expression. Transcript splice-site defects were not identified in any of the index cases and X-chromosome inactivation was not highly skewed in the six females. These data do not suggest that GLA intronic variants, per se, are pathogenic. Nonetheless, it is clear that a certain intronic haplotype in males with cryptogenic stroke is associated with reduced GLA expression and function.

Comparison of Parkinson risk in Ashkenazi Jewish patients with Gaucher disease and GBA heterozygotes

IMPORTANCE

Information on age-specific risk for Parkinson disease (PD) in patients with Gaucher disease (GD) and glucocerebrosidase (GBA) heterozygotes is important for understanding the pathophysiology of the genetic association and for counseling these populations.

OBJECTIVE

To estimate the age-specific risk for PD in Ashkenazi Jewish patients with type 1 GD and in GBA heterozygotes.

DESIGN, SETTING, AND PARTICIPANTS

The study included patients with GD from 2 tertiary centers, Shaare Zedek Medical Center, Jerusalem, Israel (n = 332) and Mount Sinai School of Medicine, New York, New York (n = 95). GBA noncarrier non-PD spouse control participants were recruited at the Center for Parkinson's Disease at Columbia University, New York (n = 77). All participants were Ashekanzi Jewish and most patients (98.1%) with GD carried at least 1 N370S mutation.

MAIN OUTCOMES AND MEASURES

The main outcome measure was a diagnosis of PD. Diagnosis was established in patients with GD on examination. We used a validated family history interview that identifies PD with a sensitivity of 95.5% and specificity of 96.2% to identify PD in family members. Kaplan-Meier survival curves were used to estimate age-specific PD risk among patients with GD (n = 427), among their parents who are obligate GBA mutation carriers (heterozygotes, n = 694), and among noncarriers (parents of non-PD, non-GD control participants, n = 154). The age-specific risk was compared among groups using the log-rank test.

RESULTS

Among those who developed PD, patients with GD had a younger age at onset than GBA heterozygotes (mean, 54.2 vs 65.2 years, respectively; P = .003). Estimated age-specific risk for PD at 60 and 80 years of age was 4.7% and 9.1% among patients with GD, 1.5% and 7.7% among heterozygotes, and 0.7% and 2.1% among noncarriers, respectively. The risk for PD was higher in patients with GD than noncarriers (P = .008, log-rank test) and in heterozygotes than noncarriers (P = .03, log-rank test), but it did not reach statistical significance between patients with GD and GBA heterozygotes (P = .07, log-rank test).

CONCLUSIONS AND RELEVANCE

Patients with GD and GBA heterozygotes have an increased age-specific risk for PD compared with control individuals, with a similar magnitude of PD risk by 80 years of age; however, the number of mutant alleles may play an important role in age at PD onset.

Anesthetic management for oocyte retrieval: An exploratory analysis comparing outcome in in vitro fertilization cycles with and without pre-implantation genetic diagnosis

PURPOSE:

To date, there has been no comparison of outcomes in women undergoing anesthesia for in vitro fertilization (IVF) oocyte retrieval for the purpose of pre-implantation genetic diagnosis (PGD) because of their or their partner's genetic disease relative to the outcome in women requiring IVF because of fertility issues.

MATERIALS AND METHODS:

A prospective observational study, wherein all demographic and anesthetic management data were collected from IVF and PGD units' records for a 6-month period. Descriptive analyses and parametric tests were employed.

RESULTS:

There were 307 cases IVF and 76 cases PGD: most (97.4% and 99.7%, respectively) received general anesthesia with propofol and fentanyl ± dipyrone (90.5% and 93.3%, respectively) with no adverse effects. The only statistically significant difference between IVF and PGD groups that was potentially clinically significant was post-procedure recovery time (23.0 ± 20.4 vs. 29.4 ± 35.8 min, respectively; P < 0.0001), but is explainable as greater caution by Anesthesiologists for higher-risk PGD cases having autosomal dominant diseases that may impact anesthesia management (myotonic dystrophy, neurofibromatosis, Marfan's); two of these cases also recovered in the general post-anesthesia care unit, as a precaution for early diagnosis and treatment of potential post-procedural complication.

CONCLUSIONS:

Results of this first-ever survey of anesthesia for PGD compared with IVF cases imply that propofol-and-fentanyl-based anesthesia is safe and can be recommended, bearing in mind that with patients who have autosomal dominant diseases impacting anesthetic management it is prudent to be more cautious post-recovery.

Vitamin D receptor polymorphism FokI is associated with spontaneous idiopathic preterm birth in an Israeli population

OBJECTIVE

The active form of vitamin D (1,25[OH]2D3) has been established to have potent anti-proliferative, immuno-modulatory, and anti-microbial action in addition to its effects on bone. The nuclear vitamin D receptor (VDR) is expressed in the placenta-decidua, regulating genes associated with implantation and implantation immuno-tolerance. If VDR polymorphisms regulate VDR functionality at the placenta-decidua interface, VDR genotypes may be involved in idiopathic preterm birth (PTB).

STUDY DESIGN

Maternal and fetal (umbilical cord) blood samples from 33 Jewish and Arab mothers with PTB of a singleton neonate were compared to 98 samples from Jewish and Arab maternal and fetal blood samples from full-term, uncomplicated singleton births. Maternal age and ethnicity were comparable between groups. PCR amplification/digestion identified the VDR SNPs: FokI, ApaI, TaqI, and BsmI.

RESULTS

Allele frequency for the FokI VDR in maternal blood samples from preterm births (but not umbilical cord samples) was significantly different (p=0.01) from that in maternal and umbilical cord blood samples from full-term singleton births, with an odds ratio for FokI carriers of 3.317 (95% CI, 1.143, 9.627) for preterm birth. The FokI VDR variant may therefore be a maternal risk trait for PTB among these women.

CONCLUSION

This study may support a future platform for the study of vitamin D during pregnancy and treatment of selective target populations with vitamin D and/or VDR "tissue-specific therapeutic intervention" for prevention of PTB.

Glucosylsphingosine is a highly sensitive and specific biomarker for primary diagnostic and follow-up monitoring in Gaucher disease in a non-Jewish, Caucasian cohort of Gaucher disease patients

Background

Gaucher disease (GD) is the most common lysosomal storage disorder (LSD). Based on a deficient β-glucocerebrosidase it leads to an accumulation of glucosylceramide. Standard diagnostic procedures include measurement of enzyme activity, genetic testing as well as analysis of chitotriosidase and CCL18/PARC as biomarkers. Even though chitotriosidase is the most well-established biomarker in GD, it is not specific for GD. Furthermore, it may be false negative in a significant percentage of GD patients due to mutation. Additionally, chitotriosidase reflects the changes in the course of the disease belatedly. This further enhances the need for a reliable biomarker, especially for the monitoring of the disease and the impact of potential treatments.

Methodology

Here, we evaluated the sensitivity and specificity of the previously reported biomarker Glucosylsphingosine with regard to different control groups (healthy control vs. GD carriers vs. other LSDs).

Findings

Only GD patients displayed elevated levels of Glucosylsphingosine higher than 12 ng/ml whereas the comparison controls groups revealed concentrations below the pathological cut-off, verifying the specificity of Glucosylsphingosine as a biomarker for GD. In addition, we evaluated the biomarker before and during enzyme replacement therapy (ERT) in 19 patients, demonstrating a decrease in Glucosylsphingosine over time with the most pronounced reduction within the first 6 months of ERT. Furthermore, our data reveals a correlation between the medical consequence of specific mutations and Glucosylsphingosine.

Interpretation

In summary, Glucosylsphingosine is a very promising, reliable and specific biomarker for GD.

Functional and genetic characterization of the non-lysosomal glucosylceramidase 2 as a modifier for Gaucher disease

Background

Gaucher disease (GD) is the most common inherited lysosomal storage disorder in humans, caused by mutations in the gene encoding the lysosomal enzyme glucocerebrosidase (GBA1). GD is clinically heterogeneous and although the type of GBA1 mutation plays a role in determining the type of GD, it does not explain the clinical variability seen among patients. Cumulative evidence from recent studies suggests that GBA2 could play a role in the pathogenesis of GD and potentially interacts with GBA1.

Methods

We used a framework of functional and genetic approaches in order to further characterize a potential role of GBA2 in GD. Glucosylceramide (GlcCer) levels in spleen, liver and brain of GBA2-deficient mice and mRNA and protein expression of GBA2 in GBA1-deficient murine fibroblasts were analyzed. Furthermore we crossed GBA2-deficient mice with conditional Gba1 knockout mice in order to quantify the interaction between GBA1 and GBA2. Finally, a genetic approach was used to test whether genetic variation in GBA2 is associated with GD and/ or acts as a modifier in Gaucher patients. We tested 22 SNPs in the GBA2 and GBA1 genes in 98 type 1 and 60 type 2/3 Gaucher patients for single- and multi-marker association with GD.

Results

We found a significant accumulation of GlcCer compared to wild-type controls in all three organs studied. In addition, a significant increase of Gba2-protein and Gba2-mRNA levels in GBA1-deficient murine fibroblasts was observed. GlcCer levels in the spleen from Gba1/Gba2 knockout mice were much higher than the sum of the single knockouts, indicating a cross-talk between the two glucosylceramidases and suggesting a partially compensation of the loss of one enzyme by the other. In the genetic approach, no significant association with severity of GD was found for SNPs at the GBA2 locus. However, in the multi-marker analyses a significant result was detected for p.L444P (GBA1) and rs4878628 (GBA2), using a model that does not take marginal effects into account.

Conclusions

All together our observations make GBA2 a likely candidate to be involved in GD etiology. Furthermore, they point to GBA2 as a plausible modifier for GBA1 in patients with GD.

Histologic findings of femoral heads from patients with Gaucher disease treated with enzyme replacement

OBJECTIVES

To assess correlations of patient demographics, including enzyme replacement therapy (ERT) with bone histology, to facilitate decisions of whether and when to perform hip replacement surgery in patients with Gaucher disease.

METHODS

We examined the histology of surgically removed femoral heads and categorized findings by the presence or extent of osteonecrosis, Gaucher cell (GC) infiltration, and bone regeneration qualifiers using a tripartite histology-based scoring system.

RESULTS

Twenty-two patients with 26 bone specimens were evaluated. Seventeen patients (77%) were splenectomized, 16 (73%) received ERT, and 12 (55%) had the putatively milder genotype (N370S/N370S), with the rest putatively at increased risk for skeletal disease (N370S/other). The 3 histology subscores were applicable to all specimens. Osteonecrotic bone was seen in 19 of 26 (73%); osteoarthritis was seen in all cartilage specimens. Gaucher cell infiltration was not correlated with demographics or disease severity. A trend was noted between reduced GC infiltration and ERT (ρ = 0.407), but regeneration qualifiers were not correlated with ERT or other features.

CONCLUSIONS

Histologic findings of GC infiltration and bone regeneration qualifiers did not correlate with demographics or with exposure to ERT. Most specimens unexpectedly showed good regenerative responses to osteonecrosis despite heavy GC infiltration.

Safety and efficacy of velaglucerase alfa replacement therapy for patients with type 1 Gaucher disease

Gaucher disease is a multisystem disorder caused by deficiency of β-glucocerebrosidase. Exogenously delivered enzyme replacement therapy (ERT) is currently standard of care. Since 1994, intravenously delivered recombinant ERT with imiglucerase (Cerezyme; Genzyme Corporation, Cambridge, MA, USA) improves hematological, visceral and skeletal features of Gaucher disease at dosages of 15-60 units/kg bodyweight/infusion, administered every other week (EOW). Velaglucerase alfa (VPRIV^®; Shire HGT, MA, USA) is a human wild-type-sequenced ERT produced in human cell lines using proprietary Gene-Activation^® technology (Shire HGT). This article describes the results of a Phase I/II seminal trial in treatment-naive non-neuronopathic patients (including stepwise dose reduction to 30 units/kg/EOW) and three Phase III trials (two doses: 45 or 60 units/kg/EOW; switch-over from imiglucerase at identical dose; head-to-head with imiglucerase, 60 units/kg/EOW) and Phase III extension trial. Velaglucerase alfa was approved in 2010 in many countries; based on clinical trial experience, it is safe and effective in treatment-naive and switch-over patients, children and adults, splenectomized patients and those with an intact spleen.

Safety and efficacy of velaglucerase alfa in Gaucher disease type 1 patients previously treated with imiglucerase

Velaglucerase alfa is a glucocerebrosidase produced by gene activation technology in a human fibroblast cell line (HT-1080), and it is indicated as an enzyme replacement therapy (ERT) for the treatment of Gaucher disease type 1 (GD1). This multicenter, open-label, 12-month study examined the safety and efficacy of velaglucerase alfa in patients with GD1 previously receiving imiglucerase. Eligible patients, ≥2 years old and clinically stable on imiglucerase therapy, were switched to velaglucerase alfa at a dose equal to their prior imiglucerase dose. Infusion durations were 1 hr every other week. Forty patients received velaglucerase alfa (18 male, 22 female; four previously splenectomized; age range 9-71 years). Velaglucerase alfa was generally well tolerated with most adverse events (AEs) of mild or moderate severity. The three most frequently reported AEs were headache (12 of 40 patients), arthralgia (9 of 40 patients), and nasopharyngitis (8 of 40 patients). No patients developed antibodies to velaglucerase alfa. There was one serious AE considered treatment-related: a grade 2 anaphylactoid reaction within 30 min of the first infusion. The patient withdrew; this was the only AE-related withdrawal. Hemoglobin concentrations, platelet counts, and spleen and liver volumes remained stable through 12 months. In conclusion, adult and pediatric patients with GD1, previously treated with imiglucerase, successfully transitioned to velaglucerase alfa, which was generally well tolerated and demonstrated efficacy over 12 months' treatment consistent with that observed in the velaglucerase alfa phase 3 clinical trial program.

Enzyme replacement therapy with velaglucerase alfa in Gaucher disease: Results from a randomized, double-blind, multinational, Phase 3 study

Type 1 Gaucher disease (GD1), resulting from glucocerebrosidase deficiency, leads to splenomegaly, hepatomegaly, anemia, thrombocytopenia, and bone involvement. Current standard treatment is enzyme replacement therapy. Velaglucerase alfa is an enzyme replacement product for GD1, with the same amino acid sequence as naturally occurring human glucocerebrosidase. This multinational, Phase 3 trial evaluated the efficacy and safety of two doses of velaglucerase alfa in 25 treatment-naïve, anemic patients with GD1 (4-62 years of age), randomized to intravenous velaglucerase alfa 60 U/kg (n=12) or 45 U/kg body weight (n=13) every other week for 12 months. The primary endpoint was change from baseline in hemoglobin concentration in the 60 U/kg arm. At 12 months, mean hemoglobin concentrations increased from baseline [60 U/kg: +23.3%; +2.43 g/dL (P<0.001); 45 U/kg: +23.8%; +2.44 g/dL (P<0.001)], as did mean platelet counts [60 U/kg: +65.9%; +50.9 × 10(9) /L (P=0.002); 45 U/kg: +66.4%; +40.9 × 10(9) /L(P=0.01)]. Mean splenic volume decreased from baseline [60 U/kg: -50.4%, from 14.0 to 5.8 multiples of normal (MN) (P=0.003); 45 U/kg: -39.9%, from 14.5 to 9.5 MN (P=0.009)]. No drug-related serious adverse events or withdrawals were observed. One patient developed antibodies. Velaglucerase alfa was generally well tolerated and effective for adults and children with GD1 in this study. All disease-specific parameters measured demonstrated clinically meaningful improvements after 12 months.