The promise of biosimilar competition to reduce healthcare costs faces significant challenges as formulary designs and rebate structures continue to impede the adoption of adalimumab biosimilars following Humira's patent expiration. Despite the entry of multiple biosimilar competitors, market dynamics and complex pricing mechanisms have created substantial barriers to realizing their cost-saving potential.
Market Entry Challenges and Pricing Complexities
When Amgen's Amjevita (adalimumab-atto) entered the market as the first adalimumab biosimilar, it implemented a dual pricing strategy. However, the net costs often remained higher than the reference product after accounting for manufacturer copay assistance and existing rebate structures. This pricing complexity contributed to slow uptake and created confusion among healthcare providers and patients about the true cost advantages.
The situation became more complicated as additional biosimilars entered the market. Coherus Biosciences' Yusimry (adalimumab-aqvh) launched at a dramatic 90% discount to Humira's wholesale acquisition cost (WAC), pricing at $569.27 plus dispensing fees. However, long-term formulary contracts and established rebate structures prevented healthcare systems from quickly capitalizing on these potential savings.
Formulary Management and Behavioral Factors
The interplay between formulary design and behavioral psychology has significantly influenced biosimilar adoption. Formularies are not merely drug lists but are intricately connected to complex financial agreements between manufacturers, pharmacy benefit managers (PBMs), and plan sponsors. These relationships create inherent conflicts between cost reduction goals and the preservation of profitable rebate arrangements.
PBMs face particular challenges in balancing cost management with revenue preservation. The potential loss of substantial rebate revenues from high-rebate products like Humira creates a disincentive for making wholesale shifts to biosimilars. Additionally, the timing of biosimilar market entry has posed challenges, as many PBMs had already committed to formulary strategies extending into 2024 and 2025.
Recent Market Developments
Some positive movement has emerged in early 2024. CVS Health's decision to grant formulary preference to adalimumab biosimilars over the reference product resulted in a dramatic increase in biosimilar utilization, with market share jumping from 5% to 36% within one week among affected patients. However, the strategy still allowed prescribers to choose more expensive alternatives, potentially limiting the full cost-saving potential.
Other major PBMs have taken varying approaches. Express Scripts opted for formulary parity between biosimilars and the reference product, while Optum has announced plans to exclude Humira from its formulary in favor of Amjevita starting in 2025. These different strategies highlight the ongoing evolution of biosimilar adoption in the U.S. market.
Economic Impact and Future Implications
The delayed adoption of biosimilars has significant financial implications. Analysis suggests that broader access to adalimumab biosimilars could have generated approximately $6 billion in savings over just one year. This unrealized potential underscores the need for systematic changes in how formularies are managed and how contracts are structured.
For biosimilars to achieve their intended impact, fundamental changes are needed in formulary strategy and management. This may require reconsidering contract structures, rebate negotiations, and educational initiatives for healthcare providers and patients. Whether these changes come through industry self-regulation or external policy intervention remains to be seen, but the current situation clearly demonstrates the need for reform in how biosimilar adoption is managed within the U.S. healthcare system.
