Open-Label Extension Study of DCCR in Patients With Prader-Willi Syndrome

Inclusion Criteria:

1. Provide voluntary, written informed consent (parent(s) / legal guardian(s) ofpatient); provide voluntary, written assent (subjects, as appropriate)

2. Participant must:

3. Have participated in and completed the Study C602 Randomized Withdrawal (RW)Period;

4. Have participated in but discontinued from the Study C602 RW Period and atleast 16 weeks have elapsed since the date of their randomization into the C602RW Period; or

5. Have participated in Study C602 OLE period, did not consent to participate inthe RW Period, and at least 16 weeks have elapsed since the date of their C602Open-Label Extension End of Treatment Visit.

Exclusion Criteria:

1. Positive urine pregnancy test (in females of child-bearing potential)

2. Females who are pregnant or breastfeeding, and/or plan to become pregnant or tobreast-feed during or within 30 days after study participation.

3. Participation in a clinical study of an investigational drug (including approveddrugs for unapproved uses), investigational device, or therapeutic interventionsubsequent to the C602 Open-Label Extension End of Treatment Visit.