Study of Tesomet With Open-label Extension in Subjects With Hypothalamic Obesity (HO)

Key Inclusion Criteria: * Subject and, if applicable, their parent or legal guardian must be willing to provide informed consent * Diagnosis of HO secondary to damage to the hypothalamus * Female subjects must be of non-childbearing potential * At least 6 months since completion of therapy (chemotherapy, surgery, or radiation with resulting injury to the hypothalamus and/or the pituitary) with stable disease and lack of recurrence * BMI 30.0 to 60.0 kg/m², inclusive * Documented stable body weight (gain/loss \<10%) for at least 90 days prior to Screening * Stable and well-managed pituitary replacement (eg, glucocorticoid, thyroid hormone, estrogen/progestin or testosterone, desmopressin, or growth hormone) for \>2 months prior to Screening * Male subjects who are sexually active must be surgically sterile Key Exclusion Criteria: * Females who are pregnant, breastfeeding, or actively intending to become pregnant during the study * Sitting BP that meets the following criteria after 5 minutes of rest at Screening: 1. Systolic BP \>145 mmHg or \<100 mmHg; or 2. Diastolic BP \>95 mmHg or \<70 mmHg * Type 1 diabetes mellitus * History of major depressive disorder within 2 years prior to Screening, or any history of other severe psychiatric disorder (eg, schizophrenia, bipolar disorder) * Uncontrolled endocrine disorders (eg, Cushing syndrome, Addison's, hypothyroidism, hyperthyroidism) * History of bulimia or anorexia nervosa * Use of prohibited medications, including current use of selective serotonin reuptake inhibitors / serotonin-norepinephrine reuptake inhibitors (SSRIs/SNRIs)