A multicenter open-label treatment protocol (HGT-GCB-058) of velaglucerase alfa enzyme replacement therapy in patients with Gaucher disease type 1: safety and tolerability

Purpose: To evaluate the safety of velaglucerase alfa in patients with type 1 Gaucher disease who received velaglucerase alfa in the US treatment protocol HGT-GCB-058 (ClinicalTrials.gov identifier NCT00954460) during a global supply shortage of imiglucerase. Methods: This multicenter open-label treatment protocol enrolled patients who were either treatment naive or had been receiving imiglucerase. Patients received intravenous velaglucerase alfa every other week at a dose of 60 U/kg (treatment naive) or 15-60U/kg (previously treated). Results: A total of 211 (including six treatment-naive) patients were enrolled. Among the 205 previously treated patients, 35(17.1%) experienced an adverse event considered related to study drug. Among the six treatment-nave patients, one had an adverse event considered related to study drug. Infusion-related adverse events occurred in 28 (13.3%) of the 211 patients and usually occurred during the first three infusions. De novo, nonneutralizing, anti velaglucerase alfa antibodies developed during treatment in one (<1.0%) previously treated patient and none of the treatment-naive patients. Conclusion: The currently observed safety profile was consistent with those previously reported for imiglucerase and velaglucerase alfa phase III clinical trials. These results support the safety of initiating treatment with velaglucerase alfa or transitioning patients from imiglucerase therapy to velaglucerase alfa therapy.