Phenotype in patients with Gaucher disease and Parkinson disease.

BACKGROUND: Previous reports have shown an increased risk for Parkinson disease (PD) among type 1 Gaucher disease (GD) patients. However, the number of the reported cases of GD/PD is small and it is unknown whether certain GD phenotypes are associated with an increased PD risk. OBJECTIVE: To present GD and PD characteristics of adults affected by both diseases from a large Israeli GD clinic, and assess whether certain GD characteristics are associated with a higher risk for PD. METHODS: Medical files of patients >18years between 1990 and 2010 were reviewed for PD signs or symptoms. Available patients with PD underwent an additional neurological examination. Demographic and GD characteristics were compared between GD patients with and without PD using t-test and Fisher exact. Kaplan-Meier survival curves were used to estimate age-specific risk for PD among males and females. Age-specific risk for PD was compared between males and females using Cox Hazard ratio model. RESULTS: 510 type 1 GD adults (233 males; 45.7%), were evaluated. 11 PD patients were identified (2.2%). Among those with GD/PD cognitive impairment was common (7/11). Two patients underwent successful deep brain stimulation (DBS). PD diagnosis was associated with male gender (81.8% versus 44.9% male, p=0.027) and older age (mean age, PD=62.8, non-PD=47.1, p=0.004). GD phenotype and severity did not differ between the two groups, including mean Zimran Severity Score index (7.7 versus 8.3), percent splenectomized (15.8% versus 27.3%), history of avascular necrosis (13.0% versus 27.3%) and percent ever treated with enzyme replacement (49.4% versus 45.5%). CONCLUSION: Male gender and older age are risk factors for PD among GD patients, but GD severity is not associated with increased risk for PD. Further research is required to assess which GD patients are at a higher risk for PD, and why.

Pivotal trial with plant cell-expressed recombinant glucocerebrosidase, taliglucerase alfa, a novel enzyme replacement therapy for Gaucher disease.

Taliglucerase alfa (Protalix Biotherapeutics, Carmiel, Israel) is a novel plant cell-derived recombinant human ß-glucocerebrosidase for Gaucher disease. A phase 3, double-blind, randomized, parallel-group, comparison-dose (30 vs 60 U/kg body weight/infusion) multinational clinical trial was undertaken. Institutional review board approvals were received. A 9-month, 20-infusion trial used inclusion/exclusion criteria in treatment-naive adult patients with splenomegaly and thrombocytopenia. Safety end points were drug-related adverse events: Ab formation and hypersensitivity reactions. Primary efficacy end point was reduction in splenic volume measured by magnetic resonance imaging. Secondary end points were: changes in hemoglobin, hepatic volume, and platelet counts. Exploratory parameters included biomarkers and bone imaging. Twenty-nine patients (11 centers) completed the protocol. There were no serious adverse events; drug-related adverse events were mild/moderate and transient. Two patients (6%) developed non-neutralizing IgG Abs; 2 other patients (6%) developed hypersensitivity reactions. Statistically significant spleen reduction was achieved at 9 months: 26.9% (95% confidence interval [CI]: -31.9, -21.8) in the 30-unit dose group and 38.0% (95% CI: -43.4, -32.8) in the 60-unit dose group (both P < .0001); and in all secondary efficacy end point measures, except platelet counts at the lower dose. These results support safety and efficacy of taliglucerase alfa for Gaucher disease.

Booster-effect with velaglucerase alfa in patients with Gaucher disease switched from long-term imiglucerase therapy: early Access Program results from Jerusalem.

BACKGROUND: Decreased spleen and liver volumes and increased hemoglobin levels and platelet counts usually occur with enzyme replacement therapy (ERT) in symptomatic patients with Gaucher disease. Because of decreased supply of imiglucerase, an FDA-approved Early Access Program (EAP) allowed use of a new, pre-licensed ERT, velaglucerase alfa. This report provides safety and efficacy findings in patients on EAP velaglucerase alfa who completed 6, 9, or 12 months as intravenous every-other-week ERT. METHOD: EAP was approved by the Israeli Ministry of Health. All patients enrolled in the EAP were included for safety measures; only those with >6 month evaluations of hemoglobin, platelet counts, and liver and spleen volumes were included for efficacy. Descriptive statistics were employed. RESULTS: Among 71 EAP patients, there were no drug-related serious adverse events or withdrawals; one patient (1.4%) with previous hypersensitivity to a different ERT had a drug-related allergic reaction. Of 44 patients with appropriate time-period evaluations, 8 patients were treatment-naïve and responded well to velaglucerase alfa. The 36 switch-over patients remained at imiglucerase low-doses; a majority of patients showed improvements in each efficacy parameter. CONCLUSION: Switch-over from imiglucerase (10-224 months) was safe and in several patients velaglucerase alfa induced a booster-effect.

Improvement in hematological, visceral, and skeletal manifestations of Gaucher disease type 1 with oral eliglustat tartrate (Genz-112638) treatment: 2-year results of a phase 2 study.

Eliglustat tartrate is an investigational oral substrate reduction therapy for Gaucher disease type 1 that is pharmacologically distinct from intravenous enzyme replacement therapy. Eliglustat tartrate improved clinical manifestations in patients who received 50 or 100 mg twice daily for 1 year during an open-label phase 2 study (Blood. 2010;116(6):893-899). We report further improvements after 2 years of treatment in 20 patients (11 females, 9 males; mean age, 33 years) with baseline splenomegaly and thrombocytopenia and/or anemia. Statistically significant (P < .001) percentage improvements from baseline occurred in platelet count (mean ± SD, 81% ± 56%), hemoglobin level (20% ± 15%), spleen volume (-52% ± 11%), and liver volume (-24% ± 13%). Mean platelet count increased ∼ 50 000/mm(3). Mean hemoglobin level increased 2.1 g/dL overall and 3.1 g/dL in 10 patients with baseline anemia. Organ volume reductions were greatest in patients with severe baseline organomegaly. Seventeen (85%) patients met established therapeutic goals for ≥ 3 of the 4 parameters. Lumbar spine bone mineral density increased 7.8% ± 10.6% (P = .01) and T-score 0.6 ± 0.8 (P = .012), with major gains in osteoporotic and osteopenic patients. Magnetic resonance imaging assessment showed that bone marrow infiltration by Gaucher cells was decreased (8/18 patients) or stable (10/18 patients). No safety-related trends emerged during 2 years of treatment. This multisite, open-label, single-arm phase 2 study is registered at www.clinicaltrials.gov as NCT00358150.

A phase 2 study of eliglustat tartrate (Genz-112638), an oral substrate reduction therapy for Gaucher disease type 1.

Eliglustat tartrate (Genz-112638), a specific inhibitor of glucosylceramide synthase, is under development as an oral substrate reduction therapy for Gaucher disease type 1 (GD1). A multinational, open-label, single-arm phase 2 study of 26 GD1 patients (16 female, 10 male; mean age, 34 years) evaluated the efficacy, safety, and pharmacokinetics of eliglustat tartrate administered twice daily by mouth at 50- or 100-mg doses based on plasma drug concentrations. Entry criteria required splenomegaly with thrombocytopenia and/or anemia. The composite primary efficacy end point required improvement after 52 weeks in at least 2 of these 3 disease manifestations and was met by 77% (95% confidence interval [CI] = 58%-89%) of all patients and 91% (95% CI = 72%-98%) of the 22 patients completing 52 weeks. Statistically significant improvements occurred in mean hemoglobin level (1.62 g/dL; 95% CI =1.05-2.18 g/dL), platelet count (40.3%; 95% CI = 23.7-57.0 g/dL), spleen volume (-38.5%; 95% CI = -43.5%--33.5%), liver volume (-17.0%; 95% CI = -21.6%-12.3%), and lumbar spine bone mineral density (0.31 Z-score; 95% CI = 0.09-0.53). Elevated biomarkers (chitotriosidase; chemokine CCL18; angiotensin-converting enzyme; tartrate-resistant acid phosphatase) decreased by 35% to 50%. Plasma glucosylceramide and ganglioside GM3 normalized. Eliglustat tartrate was well tolerated: 7 mild, transient adverse events in 6 patients were considered treatment-related. Individual pharmacokinetics varied; mean time to maximal observed concentration was 2.3 hours and mean half-life was 6.8 hours. Eliglustat tartrate appears to be a promising oral treatment for GD1.

Disease severity in sibling pairs with type 1 Gaucher disease.

The only prognostic markers in Gaucher disease, the most common lysosomal storage disorder, are young age at first symptom/sign and the presence of null/severe mutations, both being predictive of more severe phenotypes. Therefore, it would be helpful to know whether siblings with the same genotype can be expected to experience comparable phenotypic expression. All non-neuronopathic sibling pairs in our referral clinic (1993-2008) with the same genotype were included. For each pair, gender, date of birth, severity score index at presentation, age at diagnosis and first symptom/sign, presence of bone involvement, spleen status, and use of enzyme replacement therapy were tabulated. There were 90 pairs of siblings: two sets of identical twins; 24 pairs of brothers, 24 pairs of sisters, and 42 pairs of mixed gender. For all measures of disease severity used, only in sibling pairs with an older sister and a younger brother were phenotypes significantly different between siblings. Thus, this large cohort of sibling pairs with type 1 Gaucher disease confirmed that, in general, the phenotypic expression in the younger sibling will be similar enough to that of an older affected sibling that genetic counseling may use those findings in a prognostic way.

Sixteen years of prenatal consultations for the N370S/N370S Gaucher disease genotype: what have we learned?

OBJECTIVE: Although prenatal diagnosis and genotyping are available for Gaucher disease, genetic counseling for an affected child's parents reflects the inability to predict disease course with certainty. The purpose of this survey is to ascertain disease status of children identified by prenatal screening. METHODS: All carrier couples for glucocerebrosidase mutations who were counseled at our large Gaucher Clinic were included; none had genotyped the fetus. Medical status of children was assessed by questionnaires and data were collected from clinic charts and/or telephone contact with the parents. RESULTS: Of 34 children born, 1 died in utero, 5 fetuses (N370S/N370S) aborted. Of 21 genotyped N370S/N370S, 7 children had Gaucher-like symptoms/signs but for only one child (two symptoms) were these ascribable to Gaucher disease; four children had non-Gaucher symptoms/signs. CONCLUSION: Of 21 children whose parents pursued prenatal counseling for Gaucher disease and were found to have the N370S/N370S genotype, none has presented with severe disease with follow-up of 15 years. The Israeli experience shows that Gaucher disease N370S screening does not identify children requiring treatment, but rather leads to termination of asymptomatic fetuses; this may lead to reconsideration of guidelines regarding Gaucher screening.

Poor results of drilling in early stages of juxta-articular osteonecrosis in 12 joints affected by Gaucher disease.

BACKGROUND AND PURPOSE: Gaucher disease is heterogeneous. One of the most devastating complications is bone involvement, ranging from mild osteopenia to osteonecrosis, but no markers have been discovered to predict onset and/or progression. We describe our experience in a large referral center using drilling for juxta-articular osteonecrosis in young patients with Gaucher disease. PATIENTS AND METHODS: We retrospectively reviewed medical data from all patients who were recommended to undergo drilling for osteonecrosis of juxta-articular bone of the femoral head, the humeral head, or upper tibia for acute osteonecrosis at a pre-collapse stage. RESULTS: 11 patients (mean age 34 years) underwent drilling of 12 joints with juxta-articular osteonecrosis; 3 (mean age 51 years) refused intervention. 9 joints that were drilled showed advancing joint degeneration within 0.5 to 4 years. 3 joints have undergone replacement. Of the 3 joints that did not undergo drilling, 2 have undergone replacement and 1 has collapsed with osteoarthritis. INTERPRETATION: We found equally poor outcome with and without drilling. Effective intervention can only be achieved by improving our understanding of bone physiology and pathophysiology in Gaucher disease.

Molecular aspects of osteopathy in type 1 Gaucher disease: correlation between genetics and bone density.

Bone-related complications in Gaucher disease are considered to be poorly responsive to specific enzyme replacement therapy. Polymorphisms of candidate genes associated with low bone density were investigated to see whether they are correlated with bone mineral density (BMD) and bone involvement in Gaucher disease. Genotyping for polymorphisms in candidate genes (interleukins 1alpha and 1beta, interleukin-1 receptor antagonist; cytochrome P450; collagen 1A1; low-density Lipoprotein Receptor; bone morphogenic protein 4; vitamin D receptor; and estrogen receptor 2beta) were performed using standard methodologies. BMD was measured by dual energy X-ray absorptiometry (DXA). One hundred and ninety-four patients and 100 controls were genotyped for the above polymorphisms. Thirteen haplotypes were obtained, with several correlations with BMD in patients; also, a haplotype (T889-T3954-C511-240VNTR of IL1) was significantly correlated with T-scores and Z-score for femur neck and lumbar spine (p = 0.01) in patients. Haplotypes of bone-specific candidate genes associated with BMD may predict severity of these features in Gaucher disease.