OBJECTIVES: Despite the cost-saving benefits associated with biosimilar use, the uptake of biosimilars in the United States (US) has been lower than many other countries. This study assessed the budget and access implications of increased use of adalimumab biosimilars in a hypothetical plan covering 1-million members, and for the US population.

METHODS: Ex-ante analyses were conducted using US-specific data (market shares, wholesale acquisition costs for adalimumab reference product [RP; $3,154.41/dose] and biosimilars [average $515.35/dose], proportion of population using adalimumab [0.0932%]). Assumptions were required to estimate confidential rebating practices for the RP (80%) and biosimilars (average 20%). Outputs included direct cost-savings associated with drug acquisition (total and per-member per-month [PMPM]), and the incremental number of patients that could be treated on a budget-neutral basis. Three biosimilar use scenarios were tested: 5%, 50% (approximating current and 3-year historical adoption rates) and total conversion (100%).

RESULTS: For a plan covering 1-million lives, current-day use of adalimumab biosimilars (5%) yielded $264,862 in estimated savings ($0.02 PMPM). However, if uptake was expedited to achieve the 3-year historical rates in the US, expected savings could rise to $2.4 million ($0.20 PMPM), equivalent to 222 additional patients that could be treated with biosimilar adalimumab. A theoretical complete conversion to biosimilar use could yield savings of $5.0 million ($0.42 PMPM), equivalent to 469 additional patients treated. Expanding to the US population (approximately 336 million lives) savings were an estimated $104 million (9,678 additional patients) at 5% market share, increasing to $815 million and $1.7 billion at 50% and 100% market share (76,058 and 159,063 additional patients, respectively).

CONCLUSIONS: This study demonstrates that cost-efficiencies can be realized through increased adalimumab biosimilar adoption, even if deep RP rebating is present. As healthcare budgets continue to face downwards pressure, strategies and policies to increase biosimilar uptake could help effectively manage budget constraints.