OBJECTIVES: Humira is currently one of the world’s top grossing biologics, accruing over $200 billion US dollars in global sales since its FDA approval. When patent exclusivity in the United States (US) lapsed in 2023, this paved the way for the emergence of branded equivalent biosimilars in the US. This study aimed to examine the scope of US PBM coverage for these new Humira biosimilars and determine which of them are predominantly adopted.

METHODS: We conducted a review of publicly available (Statista) to identify N=5 top PBMs in the US, focusing on their market share. We examined N=8 PBM formularies for 2024 to determine which of the N=9 branded equivalent biosimilars were included in their respective formularies. In addition, we identified which of these biosimilars are preferred when compared with Humira.

RESULTS: CVS Health, Cigna, United Health, Humana, and Prime Therapeutics, respectively, were identified as the top 5 PBMs in the US, based on their 2022 market shares. Among these 5 US PBMs, there has been a limited adoption to-date of the recently launched 9 Humira biosimilars. As of the review conducted on January 4, 2024, Hadlima was covered by 4 PBMs while Hyrimoz (both brand and generic) was covered by 3 PBMs. In addition, these two biosimilars were also preferred choices when covered by PBMs. Brand Humira still remains universally covered and preferred by all 5 PBMs in this study.

CONCLUSIONS: Despite the introduction of branded equivalent biosimilars in the US market at discounted costs compared with Humira, PBMs uptake remains limited. This low adoption by PBMs may potentially limit prescribing patterns and clinical uptake of Humira biosimilars if formularies.