A report from IQVIA recapped the US experience with Semglee, an insulin glargine biosimilar that has versions with and without an interchangeability designation, to help predict the adoption patterns of adalimumab biosimilars when they enter the market in 2023.
Authors of a IQVIA report outlined what stakeholders can take away from the US experience with Semglee, in all its forms, to help predict how the US market introduction of biosimilars referencing Humira (adalimumab) might develop.
Semglee is an insulin glargine biosimilar referencing Lantus. In 2021, it became the first biosimilar to receive an interchangeability designation from the FDA. Currently, Viatris, the drug developer, markets 2 versions of Semglee: an unlabeled version and a labeled interchangeable version. Prior to Semglee, all biosimilars on the market were offered through the medical benefit, making it difficult to ascertain market trends for future pharmacy benefit biosimilars.
In 2023, up to 10 adalimumab biosimilars will enter the market. Some will have an interchangeability designation, some will have a citrate-free formulation, and some will have a high-concentration formulation. Adalimumab biosimilars will mark the first time the market has had to handle over 5 biosimilars for the same reference product and the second drug class facing biosimilar competition that is offered through the pharmacy benefit.
“The market has not yet seen how stakeholders will respond to a blockbuster brand with multiple biosimilar competitors in the retail or specialty pharmacy market, and it will be critical for pharmacy market stakeholders to understand how these different economic drivers and reimbursement dynamics will inform strategy and decision making,” the authors explained.
Semglee Adoption Experience and Drivers
Uptake for the unlabeled Semglee was slow for the first 10 months prior to the launch of interchangeable Semglee, with Lantus holding onto 99% of the market share through November 2021. Medicaid was an exception, where Semglee captured 7% market share.
After interchangeable Semglee launched, market share jumped to 15% of commercial prescriptions by March 2022. The noninterchangeable version continued to be more popular in Medicaid plans, whereas interchangeable Semglee performed better in the commercial space.
However, the authors said that the interchangeable designation played a small part in the increased adoption, arguing that payer formulary constraints were the main driver. For many patients starting therapy with a biosimilar, their previous prescription was rejected by the payer or they chose to change their therapy to a different product. There has also been an uptick in patients switching from noninterchangeable insulin glargine to the interchangeable Semglee, which can be partly explained by the gradual removal of noninterchangeable Semglee from the market.
“As the industry anticipates what will happen with Humira and the impending adalimumab biosimilars beginning in 2023, each stakeholder has a role a play. By assessing the launch and performance of Semglee and biosimilar insulin glargine, we can provide some insight into how different stakeholders may evaluate and respond to the entry of future biosimilars that are managed under the pharmacy benefit,” the authors wrote.
Considerations for Adalimumab Biosimilars
As much as looking at the insulin glargine biosimilar market can help understand how the adalimumab biosimilar market could develop, there are some notable differences, such as price. The interchangeable version of Semglee is priced around $270 and the unlabeled version is priced around $99. By contrast, Humira can cost as much as $6000.
Additionally, the many differences between the biosimilars could lead to patients struggling to ensure that they can get a biosimilar version with the same formulation as the version of Humira that they’re used to.
The report said that pricing patterns for adalimumab biosimilars will likely follow pricing for insulin glargine biosimilars, in that they will be offered at parity with the reference product or discounted. Pricing is expected to impact the economics for other stakeholders, affecting payer coverage, pharmacy substitution policies, and patient access. However, pricing strategy coupled with insurance policies on reimbursement and rebates could mean that savings aren’t passed down to the patient, which could impact patients’ decisions on whether they want to switch to a biosimilar.
The authors noted that coverage for adalimumab products may not be uniform across payers, and adalimumab products may be subject to more control measures because they will be offered by specialty pharmacies. Interchangeability was anticipated to be most relevant in scenarios where pharmacies will contract with individual manufacturers for specific products.
Additionally, the Inflation Reduction Act is expected to change Medicare Part D benefit design by removing incentives to favor expensive reference drugs. It will also be important to define how to measure the success of biosimilars in the pharmacy setting, whether that means evaluating their uptake, their margins, or their impact on the net prices for the molecule.
The authors concluded, “With so much yet to be determined, IQVIA is committed to the consistent and data-driven tracking of biosimilar adalimumab. Much like the first year of COVID-19 and the Inflation Reduction Act, Humira’s loss of exclusivity is expected to be a major industry event and will set the tone for biosimilars to come.”