A Study of Eliglustat Tartrate (Genz-112638) in Patients With Gaucher Disease Who Have Reached Therapeutic Goals With Enzyme Replacement Therapy (ENCORE)

Gaucher disease is characterized by lysosomal accumulation of glucosylceramide due to
impaired glucosylceramide hydrolysis. Gaucher disease type 1, which is the most common form,
accounts for >90% of cases and does not involve the CNS. Typical manifestations of Gaucher
disease type 1 include splenomegaly, hepatomegaly, thrombocytopenia, anemia, bone disease,
and decreased quality of life. The disease manifestations are caused by the accumulation of
glucosylceramide (storage material) in macrophages (called Gaucher cells) which have
infiltrated the spleen and liver as well as other tissues.

Eliglustat tartrate (Genz-112638) is a small molecule drug developed as an oral therapy
which acts to specifically inhibit production of this storage material in Gaucher cells.

This study is designed to determine the efficacy, safety, and pharmacokinetics (PK) of
eliglustat tartrate (Genz-112638) in adult patients with Gaucher disease type 1 who have
been stabilized on Cerezyme.