Inclusion Criteria:

• Confirmed diagnosis of type 1 Gaucher disease with a known genotype and a documented missense gene mutation in at least one of the two mutated GBA alleles
• Clinically stable
• Treatment naïve to enzyme replacement therapy (ERT) and substrate reduction therapy (SRT) or has not received ERT or SRT in the 12 months before screening
• Willing not to initiate ERT or SRT treatment during study participation
• At the screening period visit, subjects must meet at least two of the following criteria:
• Platelet count of ≤ 150,000 per microliter
• Hemoglobin ≤ 12 g/dL for females and ≤13 g/dL for males
• Liver volume ≥ 1.25 multiples of normal
• Spleen volume ≥ 2 multiples of normal
• All subjects of reproductive potential are required to practice an acceptable method of contraception
• Provide written informed consent to participate in the study

Exclusion Criteria:

• A clinically significant disease, severe complications from Gaucher disease, or serious illness that may preclude participation in the study in the opinion of the Investigator
• During the screening period, any clinically significant findings, as deemed by the Investigator
• Partial or total splenectomy
• Documentation of moderate or severe pulmonary hypertension, defined as pulmonary arterial pressure (PAP) > 35 mmHg or significant Gaucher related lung disease
• History of allergy or sensitivity to the study drug or any excipients, including any prior serious adverse reaction to iminosugars
• Pacemaker or other contraindication for MRI scanning
• Pregnant or breast-feeding
• Current/recent drug or alcohol abuse
• Treatment with any investigational product in the last 90 days before study entry
• Treatment in the previous 90 days with any drug known to have a well defined potential for toxicity to a major organ
• Presence of symptoms of gastrointestinal, liver or kidney disease, or other conditions known to interfere with the absorption, distribution, metabolism, or excretion of drugs