Basaglar Is Not Associated With Lower Out-of-pocket Costs Than the Reference Product

The “biosimilar-like” insulin glargine Basaglar was not less expensive for patients than the reference product, Lantus, concluded the authors of a retrospective analysis of commercial pharmacy claims and pharmacy co-payment offsets in The American Journal of Managed Care.

The authors assessed uptake and out-of-pocket costs associated with Basaglar from 2014 to 2018 and concluded it was as costly for patients as the reference product Lantus.

High out-of-pocket costs for insulin products are “an important barrier to care for patients with diabetes,” according to the investigators. Their findings have “important ramifications” in light of the recent approvals of Semglee and Rezvoglar by the FDA as interchangeable insulin glargine biosimilars. The interchangeable designation allows pharmacists to automatically substitute Semglee or Rezvoglar for the reference product when filling prescriptions. Since their analysis found patients using Basaglar did not have lower out-of-pocket costs than those using Lantus, “it will be important to empirically evaluate whether Semglee will be less expensive for patients than Lantus before promoting efforts to automatically substitute it for Lantus.”

Basaglar (Eli Lilly and Boehringer Ingelheim) insulin glargine, a type of long-acting insulin, was launched in December 2016 at a 15% lower list price than Lantus. Although Basaglar was approved as a new drug (insulin products did not have a biosimilar application pathway until 2020), the authors said, “for all intents and purposes Basaglar is a biosimilar.”

Despite the lower list price, the authors said, out-of-pocket costs are “a function of plan provisions, patient cumulative health care costs, and, if coinsurances and deductibles apply, the insurer-negotiated price, not the net price.” To their knowledge, their study is the first to examine out-of-pocket costs for commercially insured Basaglar users in the United States. Their final sample included 3,822,895 claims; 2,281,099 were prior to the launch of Basaglar.

Rapid Uptake of Basaglar, But Out-of-pocket Costs Not Lower Than Those for the Reference Product

The investigators found that overall number of claims for long-acting insulin products “remained relatively constant” from 2014 to 2018. However, “market composition changed significantly over time.” When Basaglar first launched, most long-acting insulin claims were for Lantus (60%). By the last quarter of 2018, Lantus had maintained the largest market share but represented only 34% of claims. At the same time, Basaglar had grown to 14% of the market, with a growth rate of 87% in 2017 and 73% in 2018.

After Basaglar entered the market, age and gender distribution were similar between the 4 long-acting insulins: Lantus, Levemir, Tresiba, and Basaglar. However, out-of-pocket expenses were highest for Basaglar users with an average $45.69 per claim.

Basaglar users in most types of insurance plans had higher out-of-pocket costs per claim than Lantus users in the same type of plan. However, there was some variation between insurance plan types: Basaglar users in comprehensive plans paid about $13 less per claim than Lantus users, whereas those in exclusive provider organization plans paid $11 more per claim.

For preferred provider organization (PPO) plans, the investigators estimated that Basaglar users paid an average of $48.27 per claim, whereas Lantus users in PPO plans paid a mean of $42.29 per claim, a total of $460,783 potential cost savings following Basaglar market entry (December 15, 2016 to December 31, 2018).

Fewer Copayment Offsets for Basaglar Users Compared to Lantus Users

The analysis also included copayment offsets, defined as transactions in which coupons, vouchers, or discount programs were used as the primary or secondary payer. The proportion of partially or fully offset transactions represented by Lantus (60%) and Basaglar (7.5%) compared to the proportion of claims represented by Lantus (67%) and Basaglar (16%) “suggests that Basaglar offered fewer offsets to its users than Lantus,” according to the authors.

The investigators concluded that “despite similar sex and age distributions and insulin glargine utilization, Basaglar users in most plan types had higher out-of-pocket costs per claim than Lantus users in the same plan types.” They said the variation by insurance plan type suggests “benefit design plays an important role in determining out-of-pocket costs” and recommended empirically evaluating whether automatic substitution actually reduces patient out-of-pocket costs as interchangeable biosimilars become available.

Reference

Mouslim MC, Rashidi ES, Levy JF, Socal MP, Trujillo AJ. The price paradox of biosimilar-like long-acting insulin. Am J Manag Care. 2022;28(11):e405-e410. doi: 10.37765/ajmc.2022.89265.