The U.S. Food and Drug Administration (FDA) approved Merilog (insulin aspart szij) as a Novolog biosimilar to (insulin aspart) to improve glycemic control in adults and pediatric patients with diabetes mellitus. Merilog, an analogue of human rapid-acting insulin, is the first FDA-approved rapid-acting insulin biosimilar product. As a rapid-acting insulin, Merilog helps reduce blood sugar spikes during meals to improve blood sugar control in people with diabetes. The approval is for both a 3-milliliter (mL) single-use pre-filled pen for the patient and a 10-milliliter (mL) multi-dose bottle.

Merilog is the third FDA-approved insulin biosimilar product and joins the two long-acting insulin biosimilars approved in 2021 by the FDA. Approval of biosimilars can increase patient access to safe and effective treatment options.

Biologics include drugs to treat many serious diseases and chronic conditions, including diabetes. A biosimilar is a biologic that is very similar to an FDA-approved biologic (also called a reference product) that is not clinically significantly different from the biologic. In other words, patients can expect the same safety and effectiveness of the biosimilar as the reference product. To date, the FDA has approved 65 biosimilars for various diseases.

More than 38 million people in the United States have been diagnosed with diabetes, a disease that occurs when the blood glucose (sugar) level is too high. Approximately 8.4 million people in the United States rely on insulin treatment, either fast-acting or long-acting, to manage their diabetes. Insulin, a hormone produced by the pancreas, helps glucose enter cells and be used as an energy source. Due to diabetes, the pancreas does not produce enough insulin to keep blood sugar levels within normal ranges, which can lead to serious health problems for patients.

"For the millions of people who rely on daily insulin injections to treat diabetes, having a biosimilar option for their rapid-acting insulin injection can really make a difference, as biosimilars have the potential to increase access to these life-saving medicines," said Dr. Sarah Yim, director of the Office of Biologics and Biosimilars (OTBB) in the FDA's Center for Drug Evaluation and Research.

Like Novolog, Merilog should be administered five to ten minutes before the start of a meal. Merilog is given subcutaneously (under the skin) by injection into the stomach, buttocks, thighs, or upper arms. The administration of Merilog should be individualized and adjusted based on the patient's needs.

Merilog can cause serious side effects, such as hypoglycemia (low blood sugar), severe allergic reactions, and hypokalemia (low blood potassium). Other common side effects may include injection site reactions, itching, skin rashes, lipodystrophy (thickening of the skin or pitting at the injection site), weight gain, and swelling of the hands and feet.