Background 

Since the first US Food and Drug Administration (FDA) approval of a biosimilar in 2015, biosimilar availability and utilization have increased. However, adoption varies across products and sites of care. 

Biosimilars can expand treatment options and may offer opportunities to reduce drug spending while maintaining comparable clinical outcomes to their reference biologics. Their adoption, however, can be shaped by product-specific market dynamics, provider prescribing practices, and reimbursement structures. 

Claims Analysis Identifies Differences in Biosimilar Use 

Avalere Health examined biosimilar utilization among outpatient clinics, 340B hospitals, and non-340B hospitals from 2021 through 2024 to assess how adoption patterns differed across care settings.  

Key findings include: 

• Outpatient clinics led adoption: Biosimilars represented 69% of relevant biologic claims in clinics in 2024, a 32-percentage-point increase from 2021. 

• 340B hospitals trailed other settings: Biosimilar use at 340B disproportionate share hospitals was approximately 6 percentage points lower than clinics and non-340B hospitals, across all products included in the analysis. 

• Adoption varied across product categories: Some drug sets (i.e., the originator product and its biosimilars) reached biosimilar use exceeding 70% across settings, while others remained substantially lower. 

These findings indicate that broader biosimilar availability has not resulted in uniform adoption across care settings.  

Considerations for Stakeholders 

Biosimilar uptake may reflect a range of factors, including provider familiarity, formulary design, purchasing arrangements, operational processes, and evolving reimbursement policy. As the biosimilar markets continue to develop, providers, plans, manufacturers, and policymakers should consider site-of-care and product-level utilization data when assessing opportunities to support appropriate biosimilar use. 

Methods

This analysis utilized the 100% Medicare fee-for-service claims, accessed by Avalere via a research collaboration with Inovalon, Inc. and governed by a research-focused CMS Data Use Agreement. 

Avalere Health used the Health Resources and Services Administration’s Office of Pharmacy Affairs Information System database to generate a list of all 340B DSH entities and their child sites during 2021 and 2024. 

To learn more about our capabilities, connect with us.