Phase II Trial of Effect of Metreleptin Therapy in Severe Insulin Resistance

Study Description: Patients with mutations of the insulin receptor have diabetes that is challenging to control with conventional therapies, leading to early morbidity and mortality. We hypothesize that recombinant leptin (metreleptin) in these patients will improve glycemia control. Objectives: Primary Objective: To determine if 1 year of metreleptin will improve glycemia control in patients with genetic defects of the insulin receptor. Secondary Objectives: To determine mechanisms by which metreleptin improves glycemia. Endpoints: Primary Endpoint: Hemoglobin A1c. Secondary Endpoints: fasting plasma glucose, fasting insulin/C-peptide, glucose/insulin/C-peptide area under the curve during oral glucose tolerance test. Study Population: 20 male or female patients with mutations of the insulin receptor, age (Bullet)5 years, at the NIH Clinical Center. Description of Sites/Facilities Enrolling Participants: Description of Study Intervention: NIH Clinical Center Open label study of metreleptin, 0.2 mg/kg/day (max dose 0.24 mg/kg/day).