Multicenter Extension Study of Velaglucerase Alfa in Japanese Patients With Gaucher Disease

A Multicenter, Open-label Extension Study of Velaglucerase Alfa Enzyme Replacement Therapy in Japanese Patients With Gaucher Disease

Gaucher disease is an inherited deficiency of the lysosomal enzyme glucocerebrosidase (GCB) that leads to progressive accumulation of glucocerebroside within macrophages and subsequent tissue and organ damage; typically of the liver, spleen, bone marrow, and brain. Type 1 Gaucher disease affects an estimated 30,000 persons worldwide and is the most common. Type 1 Gaucher disease does not involve the central nervous system. Patients with Type 2 Gaucher disease present with acute neurological deterioration, which leads to early death. Those with Type 3 disease typically display a more sub-acute neurological course, with later onset and slower progression.

The primary objective of this study is to evaluate the long-term safety of every other week (EOW) dosing of velaglucerase alfa in Japanese patients with Gaucher disease who completed study HGT-GCB-087 and elected to continue treatment with velaglucerase alfa.

Velaglucerase alfa has been developed and approved as an enzyme replacement therapy for Type 1 Gaucher disease.

Gaucher disease is an inherited deficiency of the lysosomal enzyme glucocerebrosidase (GCB) that leads to progressive accumulation of glucocerebroside within macrophages and subsequent tissue and organ damage; typically of the liver, spleen, bone marrow, and brain.

Gaucher disease has been designated in the list of Specified Rare and Intractable Diseases by Specified Disease Treatment Research Program of Ministry of Health, Labor and Welfare (MHLW) as one of "lysosomal storage diseases" since 2001. Gaucher disease is also designated in the Medical Aid Program for Specified Categories of Chronic Pediatric Diseases.

The prevalence of mutations and the phenotype of patients with Gaucher disease in Japan differs from that in non-Japanese populations. Some patients with type 1 Gaucher disease in Japan have more severe and progressive disease compared to non-Japanese patients and the disease is characterized by an earlier onset of symptoms.

Velaglucerase alfa, a highly-purified form of the naturally occurring enzyme glucocerebrosidase, has been developed as an enzyme replacement therapy for Gaucher disease for the symptoms (anemia, thrombocytopenia, hepatomegaly, splenomegaly, and bone manifestation).

The primary objective of this study is to evaluate the long-term safety of every other week (EOW) dosing of velaglucerase alfa in Japanese patients with Gaucher disease who completed study HGT-GCB-087 and elected to continue treatment with velaglucerase alfa.

Inclusion Criteria:

• The patient has completed treatment with EOW velaglucerase alfa through Week 51 of study HGT-GCB-087.
• Female patients of child bearing potential must agree to use a medically acceptable method of contraception at all times during the study.
• The patient, the patient's parent(s)or legal guardian(s) has provided written informed consent that has been approved by the Institutional Review Board/Independent Ethics Committee(IRB/IEC)
• The patient must be sufficiently cooperative to participate in this clinical study as judged by the Investigator.

Exclusion Criteria:

• The patient has received treatment with any investigational drug, other than velaglucerase alfa, or investigational device within 30 days prior to study entry; such use during the study is not permitted.
• The patient, patient's parent(s), or patient's legal guardian(s) is/are unable to understand the nature, scope, and possible consequences of the study.
• The patient has a significant comorbidity, as determined by the Investigator that might affect study data or confound the study results.
• The patient is unable to comply with the protocol as determined by the Investigator.