A Study of RM-718 in Healthy Subjects and Patients With MC4R Pathway Impairment

Key Inclusion Criteria: Parts A and B: * Male and female subjects in good health aged 18-55 years of age at Screening. * Body mass index (BMI) ≥30 kg/m2. * Subjects who are medically healthy with normal or clinically insignificant screening results. * Subjects must use a highly effective form of contraception and follow the study contraception requirements. * Ability to communicate well with the Investigator, understand and comply with the requirements of the trial, and understand English and sign the written informed consent. Part C: * Male and female patients with HO, aged 12-65 years of age at Screening. * Patient has documented evidence of acquired HO defined as: * Diagnosis of craniopharyngioma or other brain lesion affecting the hypothalamic region and has undergone surgery, or chemotherapy, or radiation therapy involving the hypothalamus at least 6 months before Screening, OR * Documented injury to the hypothalamus at least 6 months before Screening for which surgery/radiation is not indicated. * Weight gain associated with the hypothalamic injury either before or following therapy (surgery and/or following chemotherapy or radiotherapy), and a BMI of ≥30 kg/m2 for patients ≥18 years of age or BMI ≥95th percentile for age and sex for patients 12 to \<18 years of age. * Patients must use a highly effective form of contraception and follow the study contraception requirements. * Ability to communicate with the Investigator, understand and comply with the requirem…