Study to Evaluate the Efficacy and Safety of Nizubaglustat (AZ-3102) in Patients With Gaucher Disease Type 3 (GD3)

• AZ-3102 (Drug): Daily oral intake of AZ-3102 orodispersible tablets

Primary outcomes

• Change in hemoglobin levels from Baseline [24 weeks]
• Change in platelet count from Baseline [24 weeks]
• Change in total spleen volume from Baseline [24 weeks]: Assessed using magnetic resonance imaging (MRI)

Secondary outcomes

• Change in the Clinical Global Impression of Severity (CGI-S) score compared to Baseline [24 weeks]: Scale ranges from 1 to 7, where a higher score equals a worse outcome.
• Change in the Participant/caregiver Global Impression of Severity (PGI-S) score compared to Baseline [24 weeks]: Scale ranges from 1 to 7, where a higher score equals a worse outcome.
• Clinical Global Impression of Change (CGI-C) score [24 weeks]: Scale ranges from 1 to 7, where a 1 equals improvement and 7 equals a deterioration.
• Participant/Caregiver Global Impression of Change (PGI-C) score [24 weeks]: Scale ranges from 1 to 7, where a 1 equals improvement and 7 equals a deterioration.
• Peak plasma concentration (Cmax) of Nizubaglustat [24 weeks]
• Area under the plasma concentration versus time curve (AUC0-24) for Nizubaglustat [24 weeks]
• Change in plasma and cerebrospinal fluid (CSF) concentrations of glucosylceramide (GlcCer) C16:0 and C18:0 [24 weeks]
• Change in plasma and cerebrospinal fluid (CSF) concentrations of glucosylsphingosine (glcSph) [24 weeks]

Sex: All, ages: 4 Years to 30 Years

Inclusion Criteria:

* Have a confirmed diagnosis of GD3 disease
* Have at least 2 impaired domains in the Modified Severity Scoring Tool (mSST) at Screening
* Be aged 4-30 years old at the time of informed consent
* Have the following symptoms of GD3 identified at Screening: GD-related anemia, thrombocytopenia, splenomegaly
* Female participants of childbearing potential who are sexually active and willing to follow contraceptive guidance
* Male participants with a female partner of childbearing potential who are willing to follow contraceptive guidance

Exclusion Criteria:

* Any condition at Screening or Baseline that, in the opinion of the Principal Investigator, could interfere with study assessments
* History of medical conditions other than GD3 that, in the opinion of the Principal Investigator, could confound scientific rigor or interpretation of results
* Body weight <10 kg at Screening
* Presence of a neurologic disease other than GD3
* Transfusion dependence
* Prior splenectomy
* The presence of severe renal impairment at Screening
* Prior use of an investigational drug within 3 months before Screening
* Prior participation in a clinical study involving gene therapy or stem cell transplantation
* Current treatment, or treatment in the last 12 months before Screening, with enzyme replacement therapy (ERT) and/or substrate reduction therapy (SRT)
* A positive serum pregnancy test (for women of childbearing potential)
* Electrocardiogram (ECG) with an average Fridericia-corrected QT interval (QTcF) of >450 msec for males and >470 msec for females at Screening
* Known allergies to azasugars or any study drug excipient