ARD-101 for Treatment of PWS: The Hunger Elimination or Reduction Objective Trial

Inclusion Criteria:

• Documented confirmation of Prader-Willi Syndrome (PWS)

• Stable care setting with same, single designated caregiver for at least 6 monthsprior to Visit 1

• At least 7 years of age or older in the US at the time of consent

• At least 10 years of age or older in Australia

• At least 13 years of age or older in countries outside of the US and Australia

Exclusion Criteria:

• Diagnosis of schizophrenia, bipolar disorder, personality disorder or other severemood, anxiety or eating disorder (other than hyperphagia).

• Presence of any malignancy within 5 years with the exception of basal or squamouscell carcinoma of the skin, in situ carcinoma of the service, or in situationsprostate cancer.

• Presence of clinically relevant renal, hepatic, pancreatic, cardiovascular,neurological, psychiatric, hematological, pulmonary, or GI abnormality that, in theopinion of the investigator, may preclude the patient from safe completion of thestudy

• Adults: systolic blood pressure >=160 mmHg and/or diastolic blood pressure >=100mmHg

• Children and Adolescents: systolic blood pressure >=140 mmHg and/or diastolic bloodpressure >=90 mmHg.

• Type 1 diabetes mellitus; HbA1c >8.5%

• Use of agents to promote weight gain or loss, alter hunger or appetite within 30days of Visit 1 and throughout the study.

• Use of any commercially available medication for the treatment of hyperphagia (i.e.,Vykat) within 60 days of randomization and throughout the study.

• Very high doses of glucocorticoids in the previous 3 months of Visit 1 andthroughout the study.