Objective: Eliglustat is an investigational oral substrate reduction therapy for Gaucher disease type 1 (GD1). Its skeletal effects were evaluated by prospective monitoring of bone mineral density (BMD), fractures, marrow infiltration by Gaucher cells, focal bone lesions, and infarcts during an open-label, multi-site, single-arm phase 2 trial (NCT00358150).
Materials and methods: Institutional review board approval and patient informed consent were obtained. Eliglustat (50 or 100 mg) was self-administered by mouth twice daily; 19 patients completed 4 years of treatment. All were skeletally mature (age range, 18-55 years). DXA and MRI assessments were conducted at baseline and annually thereafter. X-rays were obtained annually until month 24, and then every other year.
Results: Lumbar spine BMD increased significantly (p = 0.02; n = 15) by a mean (SD) of 9.9% (14.2%) from baseline to year 4; corresponding T-scores increased significantly (p = 0.01) from a mean (SD) of -1.6 (1.1) to -0.9 (1.3). Mean femur T-score remained normal through 4 years. Femur MRI showed that 10/18 (56%) patients had decreased Gaucher cell infiltration compared to baseline; one patient with early improvement had transient worsening at year 4. There were no lumbar spine or femoral fractures and no reported bone crises during the study. At baseline, 8/19 (42%) patients had focal bone lesions, which remained stable, and 7/19 (37%) patients had bone infarctions, which improved in one patient by year 2. At year 4, one new asymptomatic, indeterminate bone lesion was discovered that subsequently resolved.
Conclusions: Eliglustat may be a therapeutic option for treating the skeletal manifestations of GD1.