Biosimilar drug products first launched a decade ago — saving the U.S. health care system approximately $36 billion. These drug products closely reference their biologic counterparts, with no clinically meaningful differences in safety or side effects. In the last few years, the excitement surrounding biosimilars and their capabilities has grown within the industry.
Humira biosimilars enter the market — but uptake is slow
In 2023, the long-anticipated Humira biosimilars officially launched — leading plan sponsors to expect immediate savings. Despite their safety and the potential for significant cost savings for patients and health plans, biosimilar adoption has been slower than anticipated due to insurer coverage decisions, high rebates and prescriber hesitance. Another notable reason for this slow adoption is “product hopping,” a tactic used by some pharmacy benefit managers (PBMs), health plans and manufacturers to steer patients toward newer, often higher-priced brand products rather than lower-net-cost biosimilars. For example, from 2022-2023, the number of Humira (adalimumab) utilizers switching to either Skyrizi (risankizumab) or Rinvoq (upadacitinib) — other name-brand products — grew by 120%. Additionally, slow adoption of formulary placement has also played a role, with only one of the big three PBMs excluding Humira in favor of a biosimilar in the first quarter of 2024.
What happens when Humira is excluded from the formulary
To better understand the rate of Humira biosimilar adoption, the Employers Health clinical team analyzed pharmacy claims data from 284 self-insured plan sponsors that implemented a Humira exclusionary formulary. The analysis found that with the exclusion in place, 79% of Humira utilizers switched to the preferred biosimilar. Meanwhile, 9% of members “product hopped” from Humira to another branded biologic, most commonly switching to Cosentyx (secukinumab), Rinvoq or Skyrizi. The most common disease states among product-hopping members were psoriasis, psoriatic arthritis, rheumatoid arthritis and hidradenitis suppurativa. Further analysis found that product-hopping members with psoriasis, psoriatic arthritis and Crohn’s disease were more likely to switch to Skyrizi, while those with rheumatoid arthritis were more likely to switch to Enbrel (etanercept).
Of the 2,441 members included in the analysis, only 2% switched back to Humira after trying the biosimilar. Prior authorization forms indicated the most common reasons for returning to Humira were trial and failure of the biosimilar and intolerable side effects. The remaining members in the study population either did not switch to the biosimilar (4%) or product hopped after trying it (5%). These populations were not further analyzed. However, it should be noted that the preferred biosimilar was not approved across all of the same indications as the reference product for pediatric patients, likely contributing to the non-switching population.
Looking ahead
While a majority of the members impacted by the formulary exclusion of Humira switched to the preferred biosimilar, a notable proportion either switched to a different branded biologic or returned to Humira. Disease state may influence a member’s decision to product hop and choose the alternative product. Our data suggest that members who unsuccessfully switch to a biosimilar are more likely to try a different branded biologic than return to Humira. Unsuccessful switches to the preferred biosimilar are mostly due to trial and failure or intolerable side effects, not prescriber preference.
The Employers Health clinical team is actively developing a custom strategy to promote biosimilar-first product adoption to drive greater plan savings. As biosimilars continue to enter the market, we will analyze claims data and create resources with clinical insight to help plan sponsors and members understand the opportunities available to plan sponsors through biosimilars. For more information, contact our clinical team at [email protected].
