Inclusion Criteria:

• The patient (and/or their parent/legal guardian) is willing and able to provide signed informed consent prior to any study-related procedures to be performed.
• The patient is 18 to 65 years old at the time of randomization.
• The patient has a confirmed diagnosis of Gaucher disease type 1.
• The patient has received treatment with Cerezyme for at least 3 years at a prescribed dose of ≥ 20 U/kg to ≤ 60 U/kg (± 5 U/kg) q2w during the last year of treatment and has not had a dose reduction, regimen change, or treatment interruption for greater than 6 consecutive months prior to randomization.
• The patient has clinically stable Gaucher disease prior to randomization.
• Female patients of childbearing potential must have a documented negative pregnancy test prior to dosing. In addition, all female patients of childbearing potential must use a medically accepted form of contraception throughout the study.

Exclusion Criteria:

• The patient has had a partial or total splenectomy within 3 years prior to randomization.
• The patient has received pharmacological chaperones or miglustat within 6 months prior to randomization.
• The patient has Gaucher disease type 2 or 3 or is suspected of having Gaucher disease type 3.
• The patient has any clinically significant disease, other than Gaucher disease,including cardiovascular, renal, hepatic, gastrointestinal (GI), pulmonary,neurologic, endocrine, metabolic (e.g. hypokalemia, hypomagnesemia), or psychiatric disease, other medical conditions, or serious intercurrent illnesses that may confound the study results or, in the opinion of the Investigator, may preclude participation in the study.
• The patient has tested positive for the human immunodeficiency virus (HIV) antibody, Hepatitis C antibody, or Hepatitis B surface antigen.
• The patient has received an investigational product within 30 days prior to randomization.
• The patient is pregnant or lactating.