Gaucher disease: alendronate disodium improves bone mineral density in adults receiving enzyme therapy

Symptomatic patients with Gaucher disease (GD) (acid beta-glucosidase [Gcase] deficiency) are treated with injectable human recombinant GCase. Treatment results in significant decreases in lipid storage in liver, spleen, and bone marrow, but the generalized osteopenia and focal bone lesions present in many adult patients are refractory to treatment. A double-blind, 2-arm, placebo-controlled trial of alendronate (40 mg/d) was performed in adults with GD who had been treated with enzyme for at least 24 months. Primary therapeutic endpoints were improvements in (1) bone mineral density (BMD) and content (BMC) at the lumbar spine, and (2) focal lesions in x-rays of long bones assessed by a blinded reviewer. There were 34 patients with GD type 1 (age range, 18-50 years) receiving enzyme therapy who were randomized for this study. After 18 months, DeltaBMD at the lumbar spine was 0.068 +/- 0.21 and 0.015 +/- 0.034 for alendronate and placebo groups, respectively (P =.001). Long-bone x-rays showed no change in focal lesions or bone deformities in any subject in either arm. Alendronate is a useful adjunctive therapy in combination with enzyme replacement therapy (ERT) for the treatment of GD-related osteopenia in adults, but it cannot be expected to improve focal lesions.