The purpose of this study is to investigate the long-term safety of every other week dosing of an investigational drug, called GA-GCB, in patients with type 1 Gaucher disease. The patients will have completed a previous clinical trial (TKT032, TKT034 or HGT-GCB-039). The initial dose received by the patients will depend on which previous trial they completed. Doses will range between 15 U/Kg and 60 U/Kg. Dose adjustments can occur one time per 12 months. Patients may be offered to have home infusion. The patients will need to visit the study centre every 12 weeks for tests and procedures. Gaucher disease is an inherited genetic disorder. In this disorder a change in the genetic material (DNA) prevents an enzyme called glucocerebrosidase or GCB from working as well as it should. When this enzyme is not working well, fatty material called glucocerebroside accumulates in the body. As time goes on, cells in the body become overloaded with glucocerebroside and are injured or destroyed. In most patients, this results in problems with the bones, liver, spleen, blood, and nervous system. Enzyme replacement therapy has been the corner stone of treatment for Gaucher disease since the early 1990s and has been highly effective. Enzyme replacement therapy remains the preferred treatment for providing the best standard of care for patients with Gaucher disease. It is expected that patients will be on this study for 2 to 2.5 years. The maximum number of patients that will enroll into the study is 102. Clinical activity of GA-GCB will be measured by change in hemoglobin concentration and platelet count along with reduction in the liver and spleen volume. Biomarkers and bone-disease markers will also be measured.