A new study from Japan shows promise for enzyme replacement therapy with velaglucerase alfa as a treatment for Gaucher disease. The report, "A multicenter, open-label extension study of velaglucerase alfa in Japanese patients with Gaucher disease: Results after a cumulative treatment period of 24 months," appeared in the medical journal Blood, Cells, Molecules and Diseases.
In Gaucher disease, glucocerebroside, a type of fatty substance, accumulates in cells and does not get broken down by lysosomes, the cellular structures that break down molecules. People with Gaucher disease, which is caused by mutations in the GBA1 gene, experience fatigue, bruising, anemia, and enlarged organs, among other symptoms. Enzyme replacement therapy is a common treatment for Gaucher disease to replace the lost enzyme glucocerebrosidase.
The current study examined a long-term extension study of the medication velaglucerase alfa. Velaglucerase alfa is made in human cells using genetic technologies, and is a type of enzyme replacement therapy.
The initial study was a 12-month Phase 3 trial in people with Gaucher disease who had been switched from the enzyme replacement therapy imiglucerase. Five patients -- two adults and three children -- participated in the extension study for an additional 12 months to examine long-term effectiveness and drug safety.
No one withdrew from the study. Six serious but not drug-related side effects occurred. Clinical measurements remained stable over the duration of the 24 months, specifically: "Hemoglobin concentrations, platelet counts, and liver and spleen volumes (normalized to body weight) in these patients were generally stable over a cumulative 24-month period from the baseline of the parent trial." The participants did not have an immune response to the medication.
The data indicates that velaglucerase produces tolerable side effects and retains its clinical effects over two years in people who previously took imiglucerase as enzyme replacement therapy.
In the study report, the scientists concluded "The data suggest that velaglucerase alfa was well tolerated and maintained clinical stability in Japanese GD patients over two years after switching from imiglucerase."
The 24-month Phase 3 trial shows promise for the treatment of Gaucher disease. In the United States, velaglucerase alfa was approved for type 1 Gaucher disease by the FDA in 2010 and is sold under the brand name VPRIV.