Open-Label Extension Study Evaluating Long Term Safety in Patients With Type 1 Gaucher Disease Receiving DRX008A (ERT)

An Open-Label Extension of Study TKT025 Evaluating Long Term Safety in Patients With Type 1 Gaucher Disease Receiving DRX008A Enzyme Replacement Therapy

Gaucher disease is a rare lysosomal storage disorder caused by the deficiency of the enzyme glucocerebrosidase (GCB). Due to the deficiency of functional GCB, glucocerebroside accumulates within macrophages leading to cellular engorgement, organomegaly, and organ system dysfunction. The purpose of this study is to evaluate the long term safety of enzyme replacement therapy with DRX008A (VPRIV®, GA-GCB; velaglucerase alfa) in patients with type 1 Gaucher disease.

Type 1 Gaucher disease, the most common form, accounts for more than 90% of all cases and does not involve the central nervous system (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 (the long term safety of enzyme replacement therapy with DRX008A (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 (velaglucerase alfa) contains terminal mannose residues that target the enzyme to the macrophages-the primary target cells in Gaucher disease. This study was designed to evaluate the long term safety of GA-GCB (velaglucerase alfa) in patients with Type 1 Gaucher disease

Inclusion Criteria:

• Patients who have completed through Week 41 visit in the TKT025 study.
• Patients must have voluntarily signed an IRB/EC approved informed consent form after all relevant aspects of the study have been explained and discussed with the patient.
• Patient must be sufficiently cooperative to participate in this clinical study as judged by the Investigator.
• Female and male patients of child bearing potential must agree to use a medically acceptable method of contraception at all times during the study. Female patients must have a negative serum pregnancy test on enrollment.

Exclusion Criteria:

• Patient has received treatment with non-Gaucher disease related investigational drug or device within the past 30 days prior to study entry; such use during the study is not permitted.
• Patient has a clinically relevant medical condition (e.g., HIV, hepatitis B or C) that would make implementation of the protocol difficult and/or confound an assessment of the effects of the experimental therapy and its adverse events.
• Patient, patient's parent(s), or patient's legal guardian is unable to understand the nature, scope and possible consequences of the study.
• Patient is unable to comply with the protocol, e.g. uncooperative attitude, medical condition, inability to return for safety evaluations, or is otherwise unlikely to complete the study, as determined by the Investigator.