Oncology · Medical Literature
Reporting Error
Abstract
In the Original Investigation titled “Hospital Adoption and Pricing for Oncology Biosimilars” published online March 11, 2026, how Medicare marks up acquisition of oncology biosimilars compared with biologics was adjusted in the article’s Discussion section. This was corrected online.
Clinical relevance
This JAMA Original Investigation (Robinson JC et al., JAMA 2026;335[14]:1243–1249) addresses a critical gap in oncology drug economics: whether hospital adoption of biosimilars for physician-administered cancer biologics is occurring, and who is capturing the resulting savings. With biologics now comprising >51% of total US drug spending and multiple oncology agents losing patent protection, understanding the financial dynamics of biosimilar adoption in the 'buy-and-bill' reimbursement model is essential for oncologists, hospital formulary committees, and health system leaders. A subsequently issued correction adjusted a claim in the Discussion regarding how Medicare marks up biosimilar versus biologic acquisition costs; clinicians should consult the corrected online version for accurate Medicare-specific markup comparisons.
Key findings
1. Biosimilar adoption increased substantially from 2020 to 2024 across all three studied agents in 1,541 hospitals and >66,000 privately insured patients: bevacizumab biosimilar share rose from 32% to 93%, trastuzumab from 37% to 87%, and rituximab from 18% to 84%. 2. Hospital acquisition prices paid to manufacturers for biosimilars fell steeply: −60% for bevacizumab, −72% for trastuzumab, and −63% for rituximab over the study period. 3. Insurer reimbursement prices to hospitals declined far more slowly: −32% for bevacizumab, −36% for trastuzumab, and −34% for rituximab — roughly half the rate of acquisition price decreases. 4. The resulting percentage price markups (margin ÷ acquisition price) grew 2.6- to 5.1-fold depending on the agent: bevacizumab markups rose from 298% to 778%, trastuzumab from 181% to 924%, and rituximab from 284% to 916%. 5. In multivariable analysis accounting for hospital characteristics (including 340B eligibility), the retained hospital margin per dollar of biosimilar acquisition cost increased by $2.72 for bevacizumab, $1.82 for trastuzumab, and $2.32 for rituximab — and these higher markups were positively associated with greater biosimilar adoption. 6. An accompanying editorial noted that hospitals absorbed a substantial portion of collective savings that could have been realized by payers and patients, underscoring that biosimilar adoption, while robust, has not uniformly translated into downstream cost reductions for insurers or patients.
Practice implications
Hospital pharmacy and formulary committees should recognize that the financial architecture of the buy-and-bill system currently incentivizes biosimilar adoption through enhanced hospital margins rather than payer or patient savings — a mechanism that, while effective at driving substitution, warrants transparent gainsharing agreements between hospitals and insurers to ensure downstream affordability. Oncology program leaders should use these data to negotiate formulary pathways that explicitly pass a portion of biosimilar savings to patients with high cost-sharing obligations, particularly for bevacizumab (colorectal, lung, cervical cancers), trastuzumab (HER2+ breast and gastric cancers), and rituximab (B-cell lymphomas, CLL). Clinicians and administrators should consult the corrected online version of this article (doi:10.1001/jama.2026.1777) for the accurate Medicare markup figures before applying the Discussion-section comparisons to Medicare Part B reimbursement policy or institutional contracting decisions.