Open-Label Study of Setmelanotide in Hypothalamic Obesity

Inclusion Criteria: Participants must meet all of the following criteria to be eligible for study participation: * Participant has documented evidence of HO, including: * Recent evidence of hypothalamic injury on magnetic resonance imaging (MRI); AND * Diagnosis of craniopharyngioma or other non-malignant brain tumor affecting the hypothalamic region; AND * Has undergone surgery, or chemotherapy, or radiation ≥6 months and ≤15 years before Screening. * Participant has either unilateral hypothalamic lesions or bilateral hypothalamic lesions, as assessed by MRI. * Obesity, documented by a body mass index (BMI) ≥35 kilograms/square meter (kg/m\^2) for participants ≥18 years of age or BMI ≥95th percentile for age and gender for participants 6 to \<18 years of age. * Documented increase in BMI (change from pre-surgery baseline in BMI z-score ≥0.2 for participants \<18 years of age or BMI \>5% for participants \>18 years of age) either during the first 6 months following surgery or within 1 year before surgery AND still present at Screening. * More than 6 months after the end of post-tumor treatment, including chemotherapy, surgery, or radiation. * Highly effective contraception throughout the study and for 90 days following the study. * Ability to communicate well with the Investigator, understand and comply with the requirements of the study, and understand and sign the written informed consent, or, for participants aged \<18 years, a parent/legal guardian that can sign.…