Biosimilar underutilization alone does not foretell a broken biologics market

Abstract

Biosimilars offer the potential for cost savings and expanded access to biologic products; however, there are concerns regarding the rate of biosimilar uptake. We assessed the relationship between biosimilar and originator pricing, coverage, and market share by describing four case studies that fall into two categories: (1) sole preferred coverage strategy (ie, aim is to have originator product preferred; biosimilar(s) non-preferred), defined as steep average sales price (ASP) reductions for originator products (decline in net prices by at least 50% following the introduction of biosimilar competition by 2022) and (2) non-sole preferred coverage strategy (ie, aim is to have originator product preferred alongside biosimilar products), defined as moderate ASP reductions for originator products with (net prices did not decline by at least 50% of its pre-biosimilar competition value). We found that originators with sole preferred coverage strategies maintained formulary preference and market share relative to originators with non-sole preferred coverage strategies. Regardless of strategy, the market-weighted ASP for all four product families (originator and biosimilars) declined significantly in the years following the introduction of biosimilars, suggesting that biosimilar uptake alone may not be a complete measure of whether the biosimilar market is facilitating competition and lowering prices.

Keywords: ASP; WAC; average sales price; biologics; biosimilar competition; biosimilars; filgrastim; infliximab; originator; payer coverage; pegfilgrastim; trastuzumab; wholesale acquisition cost.

Figure 1.

Payer preference for originator and biosimilar products, 2017-2022 (%). Source: Author's analysis of payer coverage data from the Specialty Drug Evidence and Coverage database.

Figure 2.

Market share for originator and biosimilar products, 2017-2022 (%). Source: Author's analysis of market share data from IQVIA Longitudinal Access and Adjudicated Dataset and PharMetrics Plus database (data on pharmacy and medical claims in each quarter from biosimilar entry).

Figure 3.

Weighted average sales price for originator and biosimilar products, 2017-2022 (%). Source: Author's analysis of weighted average sales price information from the Center for Medicare and Medicaid Services.