Analysis: PBMs Block Access to Lantus Biosimilars

Despite the introduction of both branded and unbranded interchangeable biosimilars, the long-acting insulin Lantus (insulin glargine) has retained majority share across payer channels, according to a new analysis by the Biosimilars Council, a division of the Association for Accessible Medicines (AAM). Using data analyzed by IQVIA, the report tracks the adoption trend of biosimilar insulin by comparing Semglee (insulin glargine-yfgn), an interchangeable biosimilar, and its unbranded version with Sanofi’s Lantus.

Sanofi, however, will reduce the price 78% starting January 2024. In March 2023, Sanofi followedannouncements from Novo Nordisk and Eli Lilly that it would reduce the list price of its insulin product. In addition to the price cut, the company will establish a $35 cap on out-of-pocket costs for patients with commercial insurance.

The Biosimilars Council analysis finds that six quarters after the launch of Viatris’ Semglee and its unbranded version, Lantus accounts for 54% of new prescriptions and is 78% of total market volume. Demand (the share of new prescriptions written) for the unbranded insulin glargine, however, has increased in the past year. Insulin glargine’s new prescriptions increased from 25% to 49% from first quarter of 2022 to first quarter of 2023.

Semglee and the unbranded version of insulin glargine launched in November 2021 to treat adults and pediatric patients with type 1 diabetes and adults with type 2 diabetes. At the time, they were the first interchangeable biosimilars to Lantus. Since then, a second interchangeable biosimilar has been approved: Lilly’s Rezvoglar (insulin glargine-aglr). Viatris also markets a non-interchangeable Semglee that is being phased out.

The Biosimilars Council’s analysis has found that many payers still do not cover the unbranded biosimilar of insulin glargine, which has a list price of $99 compared with $269 for the interchangeable Semglee and $292 for Lantus.

Among the larger PBM formularies that Formulary Watch reviewed, Optum Rx has excluded Semglee and the unbranded insulin glargine are from its Premium Standard Formulary. On its Select Standard Formulary, the unbranded version is a tier 3 product with prior authorization required. Lantus, however, is a tier 2 product without prior authorization on both the Premium and Select formularies. Tier 3 products have the highest costs for patients.

CVS Caremark excludes the reference product Lantus on its Performance Drug List, standard control, which was updated for July. Semglee and the unbranded insulin glargine is not mentioned on July 2023 drug list, which has been removed the company’s website.

Express Scripts and Prime Therapeutics announced in November 2021 that they would put Semglee on their formularies. Prime Therapeutics began preferring Semglee over Lantus beginning in January 2022.

Express Scripts has placed Semglee on its National Preferred Formulary and insulin glargine on its National Preferred Flex Formulary, which a spokesperson said is yielding reduced out-of-pocket costs for patients across the range of plan designs. Express Scripts also has included Semglee in its Patient Assurance Program (PAP), which caps patients’ out-of-pocket cost at $25 for up to a month’s supply of insulin.

“All formulary decisions, our primary concern is clinical appropriateness. After clinical considerations, formulary preference is given to high-value therapies with the lowest net cost,” the spokesperson said.