This trial is being conducted in pediatric patients with Hypothalamic Obesity. This generally occurs in people who have had an injury to or tumor in their hypothalamus (gland or organ that secretes hormones). The purpose of this trial is to see how an investigational treatment controls the hormone insulin by lowering the level of insulin in the body resulting in a weight loss in children who are at least 6 years of age but less than 18 years of age. Some children in this trial will receive placebo.