First Insulin Aspart Biosimilar Receives FDA Approval

Merilog (insulin-aspart-szjj) is the first rapid-acting insulin biosimilar to Novolog (insulin aspart) that is designated to improve glycemic control in adults and adolescents with type 2 diabetes. | Image Credit: Nirusmee - stock.adobe.com

The FDA approved Merilog (insulin-aspart-szjj; Sanofi), the first biosimilar to Novolog (insulin aspart), for glycemic control improvement among adults and adolescents with type 2 diabetes, offering a potentially more affordable treatment option for the millions of Americans who rely on insulin.¹

Over 38 million people in the US have been diagnosed with diabetes, and an estimated 8.4 million of them rely on insulin therapy, according to the FDA. The pancreas produces insulin, a hormone that enables glucose to enter the body's cells for energy use. In patients with diabetes, the pancreas does not produce enough insulin to maintain normal blood sugar levels, which can lead to serious health problems.

The first insulin biosimilar, Semglee (insulin glargine-yfgn), received approval in June 2020.² In July 2021, it also became the first biosimilar to receive an interchangeability designation from the FDA.³ A few months later, the FDA approved Rezvoglar (insulin glargine-aglr) as the second insulin glargine biosimilar in December 2021.⁴ Merilog marks the third insulin biosimilar, allowing for increased patient access to safe and effective treatment options.¹

“For the millions of people who rely on daily injections of insulin for treatment of diabetes, having a biosimilar option for their rapid-acting insulin injection can truly make a difference, as biosimilar products have the potential to increase access to these life-saving medications,” Sarah Yim, MD, director of the Office of Therapeutic Biologics and Biosimilars in the FDA’s Center for Drug Evaluation and Research, commented.

The FDA has approved Merilog in 2 forms: a 3 mL single-use self-administered prefilled pen and a 10 mL multiple-dose vial. Patients administer the prefilled pen via subcutaneous injection into the stomach, buttocks, thighs, or upper arms. Dosage is individualized and adjusted based on the patient. Patients are advised to take Merilog about 5 to 10 minutes before eating a meal.

Data from the GEMELLI-1 trial (NCT03211858), a 6-month, randomized, open-label phase 3 study, supported the approval.⁴ This study enrolled 597 people with diabetes. Researchers compared the efficacy, safety, and immunogenicity of Merilog with the originator in people with type 1 (n = 497) and type 2 diabetes (n = 100). Participants were treated with multiple daily injections of insulin glargine. The study aimed to demonstrate that the biosimilar was noninferior to the reference product in changes in hemoglobin A1C (HbA1c) from baseline to week 26.

By week 26, both groups experienced similar reductions in HbA1c (biosimilar, –0.38%; originator, –0.30%). The least squares average difference of –0.08% (95% CI, –0.192 to 0.039) confirmed noninferiority between the products. Researchers observed no clinically relevant changes in insulin doses over the 6-month treatment period. In people with diabetes treated for 26 weeks, the biosimilar demonstrated effective glycemic control and a similar safety and immunogenicity profile to the originator.

While generally well-tolerated, Merilog can cause some adverse effects in certain individuals.¹ These can include hypoglycemia, allergic reactions, and hypokalemia. Some patients may also experience injection site reactions, itching, rash, lipodystrophy, weight gain, or swelling in the hands and feet.

For the past 2 decades, pharmaceutical companies have raised insulin prices yearly, creating a century-old drug to become unaffordable, according to previous reports.⁵ Additionally, high insulin costs have shown that patients with diabetes are often rationing or forgoing insulin treatments to save money, leading to exacerbated comorbidities.

Biosimilar versions of insulin glargine have been linked to price reductions of the originator insulin products across European markets; emphasizing the promotion of biosimilar competition could be a key strategy for improving insulin affordability and accessibility. Insulin glargine biosimilars reached an average of 26% market share after 5 years on the market.

The approval of Merilog represents a potentially significant step toward lowering insulin costs in the US. By fostering a more competitive marketplace, the FDA's continued efforts to streamline the biosimilar approval process could lead to more affordable treatment options for individuals with diabetes, which could alleviate the financial burden that has forced many to ration or forgo essential care.

References

1. FDA approves first rapid-acting insulin biosimilar product for treatment of diabetes. FDA. Press release; February 14, 2025. Accessed February 19, 2025. https://www.fda.gov/news-events/press-announcements/fda-approves-first-rapid-acting-insulin-biosimilar-product-treatment-diabetes
2. Hagen T. Semglee insulin gains automatic approval under BPCIA. The Center for Biosimilars^®. June 13, 2020. Accessed February 20, 2025. https://www.centerforbiosimilars.com/view/semglee-insulin-gains-automatic-approval-under-bpcia
3. Hagen T. FDA approves Semglee insulin glargine as the first interchangeable biosimilar. The Center for Biosimilars. July 28, 2021. Accessed February 19, 2025. https://www.centerforbiosimilars.com/view/fda-approves-semglee-insulin-glargine-as-first-interchangeable-biosimilar
4. Rezvoglar broadens insulin glargine biosimilar options. The Center for Biosimilars. December 30, 2021. Accessed February 19, 2025. https://www.centerforbiosimilars.com/view/rezvoglar-broadens-insulin-glargine-biosimilar-options
5. Garg SK, Wernicke-Panten K, Wardecki M, et al. Efficacy and safety of insulin aspart biosimilar SAR341402 versus originator insulin aspart in people with diabetes treated for 26 weeks with multiple daily injections in combination with insulin glargine: a randomized open-label trial (GEMELLI 1). Diabetes Technol Ther. 2020;22(2):85-95. doi:10.1089/dia.2019.0382
6. Santoro C. Biosimilar insulin linked to lower prices in Europe. The American Journal of Managed Care^®. February 12, 2025. Accessed February 19, 2025. https://www.ajmc.com/view/biosimilar-insulin-linked-to-lower-prices-in-europe