Safety Study of rhASM Enzyme Replacement Therapy in Adults With Acid Sphingomyelinase Deficiency (Niemann-Pick Disease)

Inclusion Criteria: * Signed, informed consent by the patient or legal guardian prior to performing any study-related procedures; * Have ≤ 0.2 nmol/hr/mg protein ASM activity in peripheral leukocytes, as measured by the reference laboratory; * Have a diffusing capacity (DLco) \> 30% of the predicted normal value; * Have a spleen volume ≥ 2x normal * Female patients of childbearing potential must have a serum pregnancy test negative for β-hCG and agree to use a reliable birth control method for the duration of the study. Exclusion Criteria: * Is pregnant or lactating; * Has received an investigational drug within 30 days prior to study enrollment; * Has a medical condition, including serious intercurrent illness, active hepatitis B or C or human immunodeficiency virus (HIV) infection, cirrhosis, \> stage 3 liver fibrosis, INR \>1.5, platelet count \< 60.0x10\^3/µL, significant cardiac disease (e.g. pulmonary artery pressure \> 40 mm Hg, moderate or severe valvular dysfunction, or \< 40% left ventricular ejection fraction by echocardiography (ECHO)), or any other extenuating circumstances that may significantly interfere with study compliance including all prescribed evaluations and follow-up activities; * Has had a major organ transplant (e.g. bone marrow or liver); * Has had a total splenectomy; * Has an alanine aminotransferase (ALT) or aspartate aminotransferase (AST) value \>250 IU/L or a total bilirubin \>3.6 mg/dL; * Is unwilling or unable to avoid the use of alcohol,…