Insulin
Lauren Howell, PharmD
The results of a recently published study suggest that despite new discounts, insulin prices substantially increased from 2012 to 2015. The study also found that new insulin products coming to the market caused an increase in discounting practices and lowered the net price for payers.
The study that was published in JAMA Health Forum in June 2023 set out to describe trends in insulin prices from 2012 to 2019, and more specifically, how these prices changed when several new insulin products entered the market from 2015 to 2017.
With 25% of patients admitting that cost hinders them from accessing the insulin that they need, insulin pricing has received much attention from the media and congress over the last few years. Throughout a series of congressional investigations, manufacturers have maintained the stance that insulin prices are decreasing due to confidential, commercial discounts that are negotiated between pharmaceutical manufacturers and PBMs.
Previous studies have established that drug prices decreased after generic drugs were introduced, but little research has been done on how new nongeneric drug competition affects pricing.
Five new insulin products entered the market between 2015 and 2017. Long-acting insulins Toujeo, Tresiba, and Basaglar were all approved, while Fiasp was also brought to the fast-acting market. Additionally, Admelog was introduced as a fast-acting insulin during this time. For the purposes of the study, Admelog was categorized as a fast-acting biosimilar insulin. Basaglar and Admelog are not true biosimilars because at the time that Admelog was approved, insulin was not yet considered a biologic and therefore could not have biosimilar products. In 2020, this classification changed and allowed for the introduction of interchangeable biosimilar products to be brought to the market.
Study findings
The authors categorized insulin products into three groups: long-acting insulin analogues (insulin glargine, insulin detemir, and insulin degludec), short-acting insulin analogues (insulin lispro and insulin aspart), and human insulin products (Novolin and Humulin).
Data were collected from net sales and total units from SSR Health, Medicare Part B and Part D 5% claims, Medicare Part D prescriber user files, Medicare and Medicaid spending dashboards, and the 340B covered entity database. Net pricing for drugs was estimated as list price minus commercial discount and represented the price that Part D and private insurance plans would face after rebates.
List prices for long-acting insulin products increased at an annual rate of 12.3% from 2012 to 2019. The mean net price of these long-acting insulin products increased from 2012 to 2014 and then decreased until 2019. This change averaged out to a growth rate of 0.9% across the 2012 to 2019 study period. The decrease in net pricing that was seen after 2015 was identified as a result of a significant increase in commercial discounts, which increased from 22.7% to 64.8% across the study period.
The list prices for short-acting insulin products increased at an annual rate of 12.7%. From 2012 to 2017, the mean net price increased; then, from 2018 to 2019, it decreased. There was an annual net growth of 3.4% across the study period. Mean commercial discounts also increased from 37.9% in 2012 to 66.1% in 2019.
The mean list price and net price of human insulin products increased by an annual rate of 12.3% and 9.2%, respectively, over the study period. Mean commercial discounts increased from 54.9% to 63.1% during this period as well.
What does this mean?
Overall, the results of this study showed that insulin products are highly rebated and that the net prices for payers increased at a slower pace than list prices from 2012 to 2019. Before new drugs were introduced to the market, the increase in discounts was not able to offset the increases in list prices. During that time, before competition was introduced, growth in list prices was also reflected as growth in net prices. ■