A Study of the Safety of Mibavademab in Pediatric and Adult Participants Switching From Metreleptin to Mibavademab for the Treatment of Generalized Lipodystrophy (GLD)

This study is researching an experimental drug called mibavademab. The study is focused on participants with GLD who have been on metreleptin treatment for at least 6 months with no change in dose for the last 3 months. The aim of the study is to see how safe and tolerable mibavademab is when switching from treatment with metreleptin. The study is looking at several other research questions, including: * What side effects may happen from taking mibavademab * How much mibavademab is in the blood at different times * Whether the body makes antibodies against mibavademab (which could make mibavademab less effective or could lead to side effects)

Key Inclusion Criteria: 1. Diagnosis of congenital or acquired GLD as defined by Multi-Society Practice Guidelines 2. Treatment with metreleptin for ≥6 months at time of screening at a stable dose, defined as no change in dose within the last 3 months prior to screening 3. Generally stable diet (based on participant's recall) and stable medication regimen for diabetes and/or dyslipidemia (in addition to metreleptin), for the last 3 months prior to screening 4. Willing and able to comply with clinic visits and study-related procedures. Participants who are unable/unwilling to self-inject, but are willing to have a capable caregiver inject, are considered eligible 5. Willing and able to provide, or have the treating physician provide, values of HbA1c and fasting triglycerides from at least 6 months prior to screening, as defined in the protocol Key Exclusion Criteria: 1. Treatment with over-the-counter or prescription medications for weight loss within 3 months prior to the screening visit 2. Current chronic treatment with high-dose corticosteroids, as defined in the protocol 3. Any malignancy, eg, lymphoma, within the past 1 year, prior to screening visit except for fully treated basal cell or squamous epithelial cell carcinomas of the skin or carcinoma in situ of the cervix or anus 4. Estimated glomerular filtration rate (GFR) of \