A Phase IV, Multicenter, Randomized, Dose Frequency Study of the Safety and Efficacy of Cerezyme® Infusions Every Four Weeks Versus Every Two Weeks in the Maintenance Therapy of Patients With Type 1 Gaucher Disease

Inclusion Criteria:

- The patient must provide written informed consent prior to undergoing any
study-related procedures.

- The patient has a confirmed diagnosis of Gaucher disease with a documented deficiency
of glucocerebrosidase by enzyme assay

- The patient has been genotyped or will have genotyping performed within 3 months of
study enrollment.

- The patient has been treated with Cerezyme for at least 2 years prior to study
enrollment.

- The patient has been on a stable dose of between 20-60 U/kg every 2 weeks for at
least 6 months prior to study enrollment.

- The patient is at least 18 years old.

- The patient has a hemoglobin value of ≥ 11.0 g/dL for women and ≥ 12.0 g/dL for men
and a platelet count of ≥ 100,000 mm^3.

- The patient's liver volume is ≤ 1.8 x normal confirmed by MRI or CT within 6 months
of randomization.

- The patient's spleen volume is ≤ 10 x normal confirmed by MRI or CT within 6 months
of randomization.

- The patient has a serum creatinine < 2.0 mg/dL, an ASTand ALT < 2 x upper limit of
normal and a total bilirubin < 2.0 x upper limit of normal.

- Female patients of childbearing potential must have a negative pregnancy test within
2 weeks prior to randomization into the study.

Exclusion Criteria:

- The patient is pregnant.

- The patient has evidence of neurologic or pulmonary involvement with Gaucher disease
confirmed by medical history.

- The patient has evidence of current or prior bleeding varices or liver infarction
requiring hospitalization confirmed by medical history.

- The patient has evidence of pathologic bone fractures, medullary infarctions, lytic
lesions or avascular necrosis secondary to Gaucher disease confirmed by skeletal
evaluation within 6 months of randomization.

- The patient has had a bone crisis (defined as pain with acute onset which requires
immobilization of the affected area, narcotics for relief of pain and may be
accompanied by periosteal elevation, increased white cell count, fever or
debilitation of > 3 days) within 12 months of randomization.

- Patient has received an investigational drug within 30 days of the start of their
participation in this trial. Patients may not receive any other investigational
product throughout the course of the study.

- The patient has a clinically significant disease (with the exception of symptoms
relating to Gaucher disease), including clinically significant cardiovascular,
hepatic, immunologic, pulmonary, neurologic, or renal disease, or other medical
condition, serious intercurrent illness, or extenuating circumstances that, in the
opinion of the Investigator, would preclude participation in the trial or potentially
decrease survival

- Patient has a medical, emotional, behavioral or psychological condition that in the
judgment of the Investigator would interfere with the patient's compliance with the
requirements of the study.