Who Owns Lantus?

Lantus originated from Sanofi's research into insulin analogs, modified forms of human insulin designed to have different pharmacokinetic profiles than regular human insulin. The key innovation was the development of insulin glargine, an insulin analog that is soluble at acidic pH but forms microprecipitates at physiological pH when injected subcutaneously. These microprecipitates dissolve slowly, releasing insulin glargine gradually over approximately 24 hours and providing a relatively flat, peakless insulin profile.

This pharmacokinetic profile was a significant advance over intermediate-acting insulins such as NPH insulin, which was the standard of care for basal insulin replacement before Lantus. NPH insulin has a pronounced peak of activity several hours after injection and a duration of action of only 12 to 16 hours, requiring twice-daily dosing and creating a risk of nocturnal hypoglycemia from the peak effect. Lantus's peakless, 24-hour profile allowed once-daily dosing and reduced the risk of nocturnal hypoglycemia.

The FDA approved Lantus in April 2000 for the treatment of adults with type 1 or type 2 diabetes who require basal (long-acting) insulin. The European Medicines Agency approved Lantus in June 2000. Lantus was the first long-acting insulin analog to receive regulatory approval.

Following its approval, Lantus was rapidly adopted by endocrinologists and primary care physicians. The drug's once-daily dosing, peakless profile, and reduced risk of nocturnal hypoglycemia compared to NPH insulin made it a preferred basal insulin. Lantus became one of the most prescribed insulins globally and one of Sanofi's most commercially important products.

Lantus revenues grew steadily throughout the 2000s and early 2010s, reaching peak global sales of approximately $6.4 billion in 2015. At its peak, Lantus was one of the best-selling pharmaceutical products in the world and the dominant basal insulin globally.

In anticipation of Lantus's patent expiration, Sanofi developed Toujeo (insulin glargine U-300), a higher-concentration formulation of insulin glargine (300 units/mL versus 100 units/mL for Lantus) that provides a slightly flatter and more prolonged insulin profile. Toujeo was approved by the FDA in February 2015 and was intended to serve as a successor product as biosimilar competition emerged.

Biosimilar competition began in December 2016, when Eli Lilly launched Basaglar (insulin glargine-yfgn), the first insulin glargine biosimilar in the United States. Basaglar was priced at a discount to Lantus, beginning the erosion of Lantus's market share.

In July 2021, the FDA approved Semglee (insulin glargine-yfgn, Mylan/Biocon) as an interchangeable biosimilar to Lantus, the first interchangeable biosimilar insulin approved in the United States. Interchangeable status allows pharmacists to substitute Semglee for Lantus prescriptions without physician authorization in states that permit such substitution. In December 2022, the FDA approved Rezvoglar (insulin glargine-aglr, Eli Lilly) as a second interchangeable biosimilar insulin glargine.

The entry of biosimilar competition, combined with pricing pressure from pharmacy benefit managers and payers, significantly reduced Lantus revenues from their 2015 peak. By 2024, Lantus generated approximately €1.57 billion in full-year global sales, a fraction of its peak. However, Lantus sales saw unexpected growth in 2024 and 2025 due to windfall sales from the unavailability of competing medicines. In Q3 2025, Lantus sales were €438 million, up 6.7% at constant exchange rates. Full-year 2025 Lantus sales were €1,733 million, up 10.3% at constant exchange rates. Sanofi expects customer demand to normalize in 2026 as windfall sales subside.

In 2023, Sanofi sold its U.S. diabetes and cardiovascular commercial operations to a private equity consortium. This divestment reflected Sanofi's strategic decision to focus on specialty care, particularly Dupixent, and vaccines rather than managing the declining diabetes franchise. Sanofi retained ownership of the Lantus brand and product.