Lipoatrophic diabetes is a syndrome characterized by insulin resistance in association with a paucity of adipose tissue. Patients with severe lipoatrophy die prematurely, typically from the complications of diabetes or liver disease. Experiments with lipoatrophic mice suggest that the insulin resistance is caused by the lack of adipose tissue. Adipose tissue normally produces leptin, a hormone that increases insulin action. For the last fourteen years, we have been studying the extent to which leptin deficiency causes diabetes in lipoatrophic patients. In fact, in our initial study we have seen nearly 60% amelioration of fasting glucose, triglycerides and free fatty acid levels and about 2% actual decreases from baseline HbA1c levels with 4 months of leptin replacement therapy. This response has continued to be sustained, as we continue to follow patients that have now received leptin replacement therapy for fourteen years.

This is an open-labeled study. The study monitors the safety and efficacy of recombinant methionyl human leptin (A-100) replacement in children and adults. We are looking at the long-term effects of leptin replacement on extended therapy. In this long-term replacement protocol, we will monitor metabolic control (e.g. glucose, insulin, and triglyceride levels) as primary outcome measures. Ancillary studies will evaluate the effect of Metreleptin on other hormonal axes, growth and development and on liver pathology.

We continue to evaluate the efficacy in a broader leptin deficient population of patients with lipodystrophy. Current inclusion criteria in patients greater than or equal to 5 years include female patients with leptin levels \< 12 ng/mL and male patients with leptin levels \< 8 ng/mL. We continue to seek patients who meet these criteria. In children ages 6 months 5 years, we will use a cut-off leptin level of 6 ng/mL in both genders.

Patients who are greater than or equal to age 5 years will be evaluated every 6 months during the first year of therapy. If no improvements are seen after 6 months of therapy, then the study medication may be increased to 150% of the predicted dose (0.09mg/kg/day for males and girls less than 10 years of age/ 0.12mg/kg/day for females 10 years of age and older) from 6 months to 1 year on therapy. If no improvements are seen after increasing to 150% of the predicted dose, then the study medication will be withdrawn. If the patient shows improvements in his/her metabolic parameters while on leptin, the patient will be invited to continue taking the study medication. The investigators will strive for all patients responding to leptin to bring their metabolic parameters into the normal range. The maximum dose of leptin that will be given is 0.24 mg/kg/day for females 10 and older, and 0.12 mg/kg/day for males and females less than 10 years of age. After the first year of treatment, the patient will be evaluated every 6 months through the second year of treatment, and then the study period will end. After two years of treatment, extending the treatment period on an annual basis will be the decision of the patient, principal investigator and Bristol-Myers Squibb (BMS)/AstraZeneca Pharmaceuticals (AZ). Leptin is supplied by BMS/AZ, and is currently only available through research studies. Neither the NIH nor BMS/AZ can guarantee that leptin will be available indefinitely and/or after the study ends. However, leptin was recently approved by the FDA on February 25, 2014, for use in patients with generalized lipodystrophy.

All patient referrals for acceptance into the protocol, are initiated by the physician/health care provider.