Optimization of Eliglustat-Based Glucosylceramide Synthase Inhibitors as Substrate Reduction Therapy for Gaucher Disease Type 3

Intraocular lesions have been infrequently reported in patients with Gaucher disease type 3 (GD3). We previously reported siblings with GD3 who responded well to the combination of enzyme replacement therapy (ERT) and substrate reduction therapy (SRT). Here we report progressive bilateral vitreous and preretinal deposits with declining visual acuity requiring bilateral vitrectomies in one of these siblings. These ocular manifestations had progressed despite combined ERT and SRT with improvement in visual acuity after vitrectomies. Vitrectomy fluid analysis performed for the first time by ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) identified a high concentration of glucosylceramide (GluCer) in the patient (262.842 nM) compared to a sample (0.428 nM from a patient without a lysosomal storage or known hereditary metabolic disorder). The GluCer detected in our patient was resolved into 12 different isoforms including two methylated ones. No evidence of galactosylceramide (GalCer) was detected. The development of these intraocular manifestations and their characterization by UPLC-MS/MS indicate a need for ongoing ophthalmologic evaluation of all GD patients and for new therapies that can cross the blood–retinal and blood–brain barriers for patients with GD and other neuropathic lysosomal storage disorders.

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

Blood ◽

10.1182/blood-2010-03-273151 ◽

2010 ◽

Vol 116 (6) ◽

pp. 893-899 ◽

Cited By ~ 105

Author(s):

Elena Lukina ◽

Nora Watman ◽

Elsa Avila Arreguin ◽

Maryam Banikazemi ◽

Marta Dragosky ◽

...

Keyword(s):

Gaucher Disease ◽

Disease Type ◽

Substrate Reduction Therapy ◽

Phase 2 ◽

Mineral Density ◽

Substrate Reduction ◽

Drug Concentrations ◽

Phase 2 Study ◽

Gaucher Disease Type 1

Abstract 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. This study is registered at www.clinicaltrials.gov as #NCT00358150.

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