A Study to Assess the Long-Term Safety of Pharmaceutical Grade Synthetic Cannabidiol Oral Solution in Patients With Prader-Willi Syndrome

Inclusion Criteria:

1. Completed activities up to and including Visit 10 (Study Completion) of INS011-16-
085.

2. Patient and/or parent(s)/caregiver(s) fully comprehend the informed consent form (ICF)
and assent form, understand all study procedures, and can communicate satisfactorily
with the investigator and study coordinator, in accordance with applicable laws,
regulations, and local requirements.

3. If female, is either not of childbearing potential or practicing medically acceptable
methods of birth control.

4. Psychotropic treatment will be permitted if the subject has been on a stable dose
during the INS011-16-085 and does not anticipate a dose change during the course of
the study.

5. Growth hormone treatment will be permitted if the subject has been on a stable dose
during INS01-16-085.

6. Any other treatment including thyroid hormones should be stable prior to entering the
INS011-17-115 study.

7. In the opinion of the investigator, the parent(s)/caregiver(s) is (are) willing and
able to comply with the study procedures and visit schedules, including venipuncture,
and the visit schedules.

Exclusion Criteria:

1. Patient or parent(s)/caregiver(s) have commitments during the study duration that
would interfere with attending all study visits.

2. Experienced an anoxic episode related to study drug requiring resuscitation during the
previous study.

3. Uncontrolled Type I and Type II Diabetes.

4. Developed an adverse event thought to be related to CBD in the previous study and the
investigator determines that continuing treatment with CBD would not be in the best
interest of the patient.

5. History of clinically significant gastrointestinal, renal, hepatic, neurologic,
hematologic, endocrine, oncologic, pulmonary, immunologic, psychiatric, or
cardiovascular disease, or other condition which would jeopardize safety or impact
validity of results (per investigator).

6. Currently taking felbamate.

7. Compromised respiratory function or severe respiratory insufficiency.

8. Pregnant or lactating female..

9. In the opinion of the investigator, the patient is unsuitable in any other way to
participate in this study.