Over a 10-year period, Basaglar, considered an unofficial biosimilar, achieved price drops in the insulin glargine market and took a significant market share from Lantus.
Although Semglee became the first official biosimilar insulin glargine in July 2021, Basaglar has long been considered an unofficial biosimilar because it is thought highly similar to the reference product, Lantus, although it was approved via a new drug application rather than the biosimilar pathway.
Investigators sought to compare the effect on prices that the presence of Basaglar had on the cost of Lantus. They noted a "substantial" price change as a result of the market entry of this product.
They designed the study to elucidate any pricing effect despite the influence of manufacturer rebates and limited payer information. To accomplish this, they examined US prices and sales over a 10-year period for all insulin glargine products.
Lantus, a Sanofi product, has been sold in the United States since 2000. Basaglar, also available in 100 IU/mL, is sold by Eli Lilly and Boehringer Ingelheim. Basaglar was approved by the FDA in 2014 but didn’t launch until December 2016.
The insulin glargine market was also influenced by the launch of Toujeo, another Sanofi product, which investigators described as a possible “product hop,” or effort to lure patients away from Basaglar. Toujeo had a higher concentration than Lantus and Basaglar.
However, the authors said that Toujeo never achieved a significant market share, which remained fairly consistent from 2016 until the second quarter of 2020, the study end date. Toujeo’s sales never rose above 15% market share, they said.
For the data needed to complete the analysis, investigators examined quarterly list prices, estimates of net prices after manufacturer rebates, and total US sales for insulin glargine products. List and net prices examined were expressed in 100 IU of insulin glargine. The results were adjusted for market share of each product.
From early 2010 to the third quarter of 2014, Lantus was the only insulin glargine on the market, and list prices of this product climbed to $22.21 from $9.23 during that period, a 4.9% quarterly rate of increase.
Investigators said net prices were lower than list prices ($6.94 vs $12.79) and rose each quarter at a 3.8% rate, which was a slower pace of increase than for list prices.
From 2015 to 2020, when competition was present in the market, list prices were flat but net prices of Lantus declined by 5.2% per quarter. The weighted average net price of insulin glargine (including competitor products) declined at a 3.4% quarterly rate.
“Lantus maintained the highest net sales throughout the period, although by 2020, Basaglar accounted for 39% to 41% of all net sales compared with 45% to 46% for Lantus,” authors of the study wrote.
They calculated that prior to Basaglar’s arrival on the market, the net price per 100 IU of insulin glargine increased $0.36 per quarter on average. After Basaglar’s approval, “a significant downward trend" began, with net prices decreasing an average $0.67 per quarter.
From starting out with a 100% share of the market in 2010, Lantus had a market share of 46.2% by the first half of 2020. “The approval of the biosimilar was associated with a substantial change in the trajectory of net prices for the originator product as well as the average price across products,” the authors wrote.
However, despite the careful methodology of the investigators, the exact savings and pricing effect of Basaglar remain unclear because of the opacity of manufacturer rebates, the investigators said.
“List prices were not a good measure of prices for any product, likely owing to large rebating practices by drug manufacturers in response to increased competition," they said.
Levy J, Chowdhury ZM, Socal MP, Trujillo AJ. Changes associated with the entry of a biosimilar in the insuline glargine market. JAMA Intern Med. Published online June 28, 2021. doi:10.1001/jamainternmed.2021.2769