Study of GA-GCB Enzyme Replacement Therapy in Type 1 Gaucher Disease Patients Previously Treated With Imiglucerase

Type 1 Gaucher disease, the most common form, accounts for more than 90% of all cases and
does not involve the CNS. Typical manifestations of type 1 Gaucher disease include
hepatomegaly, splenomegaly, thrombocytopenia, bleeding tendencies, anemia, hypermetabolism,
skeletal pathology, growth retardation, pulmonary disease, and decreased quality of life.
Gene-Activated® human glucocerebrosidase (GA-GCB; velaglucerase alfa) is produced in a
continuous human cell line using proprietary gene-activation technology and has an identical
amino acid sequence to the naturally occurring human enzyme. GA-GCB contains terminal mannose
residues that target the enzyme to the macrophages-the primary target cells in Gaucher
disease. This study was designed to determine the safety of GA-GCB in men, women, and
children with Type 1 Gaucher disease who were previously treated with imiglucerase. Each
participant's duration of treatment will be 12 months.

Inclusion Criteria:

Includes:

- The participant has a documented diagnosis of type 1 Gaucher disease, as determined by
deficient glucocerebrosidase (GCB) activity relative to normal as measured in
leukocytes or by genotype analysis and the participant/legal guardian is willing and
able to provide written informed consent prior to initiating any study-related
procedures

- The participant has received consistent treatment with imiglucerase at a dose ≤ 60
U/kg and ≥ 15 U/kg every other week for a minimum of 30 consecutive months.
Participants who are anti-imiglucerase antibody positive will be allowed to enter this
study

- The participant is at least 2 years of age

- Female participants of child-bearing potential agree to use a medically acceptable
method of contraception. Male participants must agree to use a medically acceptable
method of birth control

- Participant must be sufficiently co-operative to participate in the study as judged by
the Investigator.

Exclusion Criteria:

Includes:

- The participant has type 2 or 3 Gaucher disease or is suspected of having type 3
Gaucher disease

- The participant has received treatment with any investigational drug or device within
the 30 days prior to study entry; such use during the study is not permitted

- Participant is HIV positive

- Participant is hepatitis B/C positive

- The participant presents with sustained iron, folic acid and/or vitamin B12
deficiency-related anemia during Screening

- The participant, participant's parent(s), or participant's legal guardian(s) is/are
unable to understand the nature, scope, and possible consequences of the study

- The participant has a significant comorbidity that might affect study data or confound
the study results

- The participant is unable to comply with the protocol or is otherwise unlikely to
complete the study, as determined by the Investigator

- The participant has experienced an anaphylactic/anaphylactoid reaction during
treatment with imiglucerase

- The participant has received miglustat during the 6 months prior to study enrollment

- The participant has an active, clinically significant spleen infarction

- The participant has active, progressive bone necrosis

- The participant is a pregnant and/or lactating female