The FDA Approves AstraZeneca's Myalept For Lipodystrophy

AstraZeneca announced in a press release that the Food and Drug Administration (FDA) has approved Myalept and given it orphan drug status. The Myalept injection treats leptin deficiency in patients with lipodystrophy and is the first treatment approved by the FDA for this population. Astra Zeneca will be the sole owner of the new drug once intellectual property, global rights, and other assets are transferred from the Bristol-Myers Squibb Company as part of the sale of the diabetes franchise. Briggs Morrison, Executive Vice President, Global Medicines Development and Chief Medical Officer of AstraZeneca, said, “Myalept represents a significant treatment advancement for people living with this serious and rare disorder.”

Lipodystrophy

Lipodystrophy is a rare disorder affecting adipose (fat) tissue. Some patients inherit the disorder while others may acquire it through illness or drugs. Depending on the type of lipodystrophy and the severity, patients lose adipose tissue in small or large amounts. The degree of fat loss can determine whether the patient develops other metabolic diseases like diabetes. Widespread fat loss can lead to leptin deficiency causing endocrine and immune system problems. Leptin replacement therapy can restore the normal balance.

Myalept

Myalept is a recombinant analogue of human leptin, synthesized in the laboratory. It is available in a 11.3 mg vial and administered by subcutaneous injection. In a briefing document, the FDA said, “Metreleptin appears to treat the insulin resistance of lipodystrophy; to the extent diabetes and hypertriglyceridemia are the result of insulin resistance, metreleptin treatment is associated with improvements in, and in some cases normalization of, metabolic control.”

The agency noted that studies with a placebo group seemed unethical due to the compelling findings of a previous study. Therefore, approving the drug without a placebo group or adequate history of treatment was challenging. Deciphering whether the drug was effective was difficult, as patients could have improved their diets or been in better compliance with their other medications. Additionally, the FDA said that other variables made the decision difficult. However, the agency found that patients did show benefits from the drug that are unlikely to be caused spontaneously. 

Myalept is not approved for partial lipodystrophy, liver disease, HIV-related lipodystrophy, diabetes mellitus, and hypertriglyceridaemia. The drug is not indicated for obesity as it has proven not effective in this population.