A Study of Oral ARD-101 in Patients With Prader-Willi Syndrome

Inclusion Criteria: * Male and female subjects, 17-65 years of age * Provide voluntary, written informed consent (parent(s) / legal guardian(s) of participant); provide voluntary, written assent (participants, as appropriate) * PWS due to chromosome 15 micro-deletion, maternal uniparental disomy, or imprinting defect, confirmed by fluorescent in situ hybridization, chromosomal microarray, and/or methylation studies * BMI ≥ 18.5 kg/m² * Qualifying HQ-CT score Exclusion Criteria: * Use of weight loss agents, including herbal medication, within 3 months prior to enrollment * Diagnosis of schizophrenia, bipolar disorder, personality disorder, or other DSM-III disorders which the investigator believes will interfere significantly with study compliance * Clinically significant illness in the 8 weeks prior to enrollment * Current, clinically significant liver, renal, pulmonary, cardiac, oncologic, or gastrointestinal (GI) disease * Diagnosis of type 1 diabetes mellitus or other active endocrine disorders (e.g., Cushing syndrome, or thyroid dysfunction except if on stable adequate thyroid or glucocorticoid replacement supplement) * Significant history of abuse of drugs within 1 year prior to enrollment or a positive Drugs of Abuse (DOA) test at screening * History of alcohol abuse within 1 year prior to enrollment or currently drinks in excess of 21 units per week (3 servings or units/day)