Open-Label, Expanded Access Study of Taliglucerase Alfa in Patients with Gaucher Disease Requiring Enzyme Replacement Therapy

Taliglucerase alfa, an enzyme replacement therapy (ERT) approved in several countries for the treatment of adult and pediatric patients with Type 1 Gaucher disease, is the first FDA-approved plant cell-expressed recombinant therapeutic protein for humans. PB-06-004 (NCT00962260) was a multicenter, open-label, expanded access study designed to follow the safety of taliglucerase alfa in patients with Gaucher disease who required ERT and who were previously treated with imiglucerase but had a dose reduction or discontinued due to a shortage of imiglucerase. Eligible patients (aged ≥18 years) with Type 1 Gaucher disease received taliglucerase alfa every 2 weeks for ³9 months at a dose equivalent to their previous imiglucerase dose, before it was reduced or discontinued (Part A), and had the option of continuing treatment for up to 33 months (Part B); a later amendment allowed treatment-naïve patients. Fifty-eight patients received treatment (55.2% male, mean age 46.1 years, mean bi-weekly dose 35.2 U/kg, mean duration 17.8 months); 51 patients previously received ERT, 7 were treatment-naïve. Thirty-six patients completed the study. Hemoglobin concentration and platelet counts were also explored. Most adverse events (AEs) were mild or moderate in severity and not related to taliglucerase alfa; treatment-related AEs were mild and transient in nature. In previously treated patients, mean (SE) hemoglobin concentration was 13.0 (0.3) g/dL at baseline, 13.4 (0.2) g/dL at 9 months, and 13.4 (0.2) g/dL at last follow-up; mean (SE) platelet count was 179,242 (15,344)/mm³ at baseline, 209,727 (17,157)/mm³ at 9 months, and 215,242 (17,867)/mm³ at last follow-up. In treatment-naïve patients, mean hemoglobin concentration and platelet counts increased. In conclusion, taliglucerase alfa was well tolerated for up to 33 months of treatment and demonstrated a durable therapeutic effect, as evidenced by stable or improved hemoglobin concentration and platelet counts in this expanded access study.