FDA Okays New Rapid-Acting Biosimilar Insulin for Diabetes

The US Food and Drug Administration (FDA) has approved Sanofi’s Merilog (insulin-aspart-szjj), a biosimilar to Novolog (insulin aspart), for treating adults and children with diabetes. 

The approval “highlights our continued efforts to improve the efficiency of the biosimilar approval process to help support a competitive marketplace and increase options for costly treatments, like insulin. Increasing access to safe, effective and high-quality medications at potentially lower cost remains a continued priority for the FDA,” Peter Stein, MD, director of the Office of New Drugs in the FDA’s Center for Drug Evaluation and Research, said in a statement. 

Merilog is the first rapid-acting biosimilar human analog insulin approved by FDA. Since March 2020, FDA has regulated insulin and other biological product as “biosimilars” that are highly similar to, with no clinically meaningful differences from, a reference biological product that is already FDA-approved. As such, they are interchangeable with the branded products at the pharmacy level.

The FDA previously approved two long-acting insulin biosimilars, Mylan Pharmaceuticals’ Semglee in June 2020 and Lilly’s glargine biosimilar, Rezvoglar in December 2021.

Prior to establishing the “biosimilar” category for insulin and other biologic products, the agency approved Sanofi’s short-acting insulin lispro “follow-on,” Admelog in 2017, and Eli Lilly’s “authorized generic” Insulin Lispro. in 2019. The long-acting follow-on Basaglar (Lilly) was approved in 2015.

Merilog is approved as both a 3 mL single-patient-use prefilled pen and a 10 mL multiple-dose vial. Like Novolog, Merilog should be given subcutaneously within 5-10 minutes prior to the start of a meal, with doses individualized for the patient’s needs. 

Serious side effects are the same as those for other short-acting insulin analogs, including hypoglycemia, severe allergic reactions, and hypokalemia. Other common side effects may include injection-site reactions, itching, rash, lipodystrophy, weight gain, and swelling of the hands and feet.

Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape Medical News, with other work appearing in the Washington Post, NPR’s Shots blog, and Diatribe. She is on X @MiriamETucker and BlueSky @miriametucker.bsky.social.