The three dominant U.S. pharmacy benefit managers have dramatically restructured their 2025 formularies, excluding nearly all marketed Humira biosimilars in favor of their own private-label products. This represents a significant shift from previous years when multiple biosimilar options were available to plan sponsors.
Widespread Formulary Exclusions
Caremark (CVS Health), Express Scripts (Cigna), and Optum Rx (UnitedHealth Group) have removed AbbVie's Humira and most manufacturer-marketed biosimilars from their standard commercial formularies as of January 2025. Notable exclusions include Biocon Biologics' Hulio, Celltrion's Yuflyma, and both versions of Pfizer's Abrilada.
"AbbVie's Humira either has or will vanish from PBMs' standard formularies," wrote Drug Channels CEO Adam Fein, Ph.D., in his annual formulary analysis. This marks a stark contrast to early 2024, when Optum Rx covered eight adalimumab products including the reference drug.
Private-Label Strategy Emerges
Each major PBM now operates through private-label subsidiaries to offer biosimilar alternatives. Optum Rx's newest venture, Nuvaila, prefers high-list-price Amjevita from Amgen alongside low-list-price versions on its formularies. Express Scripts covers Quallent-branded biosimilars manufactured by Boehringer Ingelheim and Alvotech/Teva, while Caremark features Cordavis-branded products sourced from Sandoz.
"Instead, each PBM's formulary will give plan sponsors the option of a high-list-price biosimilar, a lower-priced private label product, and a low-list-price unbranded biosimilar," Fein noted.
Market Impact and Competitive Dynamics
The formulary changes have already demonstrated market impact. Caremark's removal of Humira from major commercial formularies in the second quarter of 2024, while favoring cobranded versions, has been credited with allowing biosimilars to meaningfully chip away at the reference product's market share for the first time.
Currently, 14 Humira biosimilars compete in the U.S. market, treating conditions including Crohn's disease, psoriatic arthritis, and ulcerative colitis. The drug has generated approximately $200 billion for AbbVie since its 2002 launch, making it one of the most valuable pharmaceutical products in history.
Expert Perspectives on Strategy
Health policy experts express mixed views on the PBM approach. "The good news is that there are a lot of options for plans and payers for negotiating for lower prices for Humira," said Stacie Dusetzina, Ph.D., a Vanderbilt University professor who researches drug pricing policy. "This drug has been a blockbuster for years and has been expensive for plans and patients."
However, Dusetzina warns of potential long-term consequences: "The bad news is that if many of these products are left off of major formularies, it might frustrate manufacturers and reduce their interest in bringing new biosimilar products to the market."
Implications for Biosimilar Manufacturers
The formulary strategy creates complex market dynamics for biosimilar manufacturers. Elan Rubinstein, Pharm.D., principal at EB Rubinstein Associates, notes that cobranded biosimilars "have the best shot at market success on a volume basis" but require higher price concessions to PBMs' cobranding companies.
"A manufacturer awarded cobranded status with one of these PBMs may leave that manufacturer locked out of the other two market-dominant PBMs' formularies," Rubinstein explained, highlighting the winner-take-all nature of the current system.
Rebate Dynamics and Cost Considerations
The shift reflects ongoing tensions in pharmaceutical pricing between rebate maximization and actual cost reduction. In early 2024, PBM formularies still "supported the gross-to-net bubble for Humira biosimilars," allowing clients to receive rebates from manufacturers seeking preferential placement for high-list-price drugs.
"To drive biosimilar penetration, plan sponsors need to give up their addiction to rebates and reject the high-list products that inflate the gross-to-net bubble," Fein wrote. "Until that happens, we may need to accept that PBMs' private-label strategies are less than ideal, but better than the alternatives."
The formulary changes represent a fundamental shift in how the largest PBMs approach biosimilar competition, with implications extending beyond adalimumab to other therapeutic areas where biosimilar competition is emerging.
