Sustaining competition for biosimilars on the pharmacy benefit: Use it or lose it

Congress passed the Biologic Price Competition and Innovation Act of 2009, specifically to offer market competition as a counterweight to the rising costs of biologic medicines. As of April 15, 2024, 49 biosimilars have been approved by the US Food and Drug Administration in 15 biologic categories. Biosimilar competition has been undeniably successful: Through 2022, biosimilars have saved the US health system $23.6 billion, without significant care disruption or reduced quality. Through 2023, adalimumab biosimilar competition has added an additional $6.5 billion to this total, primarily through greater rebates from the reference manufacturer. Despite launching at discounts as great as 85%, adalimumab biosimilars have not been given preferred formulary positioning in the vast majority of cases and have thus gained only 3% of market share through 2023, largely because of payers' and pharmacy benefit managers' preference for rebates over discounts. This situation may negatively influence future biosimilar development, posing a threat to a biosimilar pipeline that represents hundreds of billions in savings over the next 10 years.