MEASuRE is a research project to learn more about the medicine metreleptin, used to treat a rare condition called lipodystrophy. Lipodystrophy is when the body has trouble storing fat properly, which can lead to health issues. This study is non-interventional, meaning it just observes patients who are already using metreleptin, without giving them any new treatments.

The study will gather information from patients in the United States and Europe who are using metreleptin. It will help scientists understand how metreleptin affects people over time, including tracking any serious health problems like pancreatitis (swelling of the pancreas), liver issues, or severe infections. It will also look at whether patients experience allergic reactions, new autoimmune diseases (when the body's defense system attacks itself), or cancer.

To join the study, patients must already be using metreleptin and agree in writing to participate. Patients currently trying new medicines in other studies cannot join.

• This study observes metreleptin use, without changing your treatment.
• Participants are observed for various side effects and health outcomes.
• Written consent is needed to be part of the study.