A Phase 3 Extension Study of RAD011 (Cannabidiol Oral Solution) in Patients With Prader-Willi Syndrome

Inclusion Criteria: * Presence of a parent/legal guardian that is able to consent for their participation. Parent/caregiver/legal guardian can complete the required assessments throughout the study. Patient Consent/Assent will be obtained if the patient is 8 years of age or older and has the mental capacity to understand and sign a written consent/assent form and/or give verbal assent; * Patient completed treatment on the SCOUT-015 study through Visit 14 (Week 34); * If female, is either not of childbearing potential (defined as premenarchal or surgically sterile \[bilateral tubal ligation, bilateral oophorectomy, or hysterectomy\]) or practicing one of the following medically acceptable methods of birth control up to 4 weeks after the last dose of RAD011 or placebo: Exclusion Criteria: * Significant acute condition (active infection, uncontrolled diabetes, any other uncontrolled chronic condition) including but not limited to clinically significant laboratory abnormality, or medical or psychosocial condition that may preclude the patient from participating in the study, at the Investigator's discretion; * Positive urine test for drugs of abuse, including tetrahydrocannabinol (THC), or known history of drug, alcohol, or substance abuse; * Significant risk of committing suicide based on history, psychiatric examination, or based on the Investigator's judgment; * Significant non-compliance issues (IP misuse or abuse, study visit participation, etc.) during the patient's SCOUT-015 participation based on the Investigator's judgement. * Pregnant (determined by a positive urine pregnancy test) or lactating female; * Concurrent participation in any other interventional study involving an investigational product, gene therapy, or device.