The newest IQVIA report reminds us of the strength of the oncology biosimilars bevacizumab, rituximab, and trastuzumab. Not only are these oncology biosimilars thriving, payers are making it increasingly difficult to obtain treatment with the innovator products when oncology biosimilars like these are available.
The number of formulary exclusions nationally for all oncology products is increasing (Table), and this is especially true where there is a generic or biosimilar alternative available. The number of formulary exclusions increased 42% since 2022, to 134. Formulary exclusions in commercial plans were nearly unheard of in 2017, and only 4 exclusions were registered in 2018 (and only because of the availability of a generic or biosimilar).
| TABLE: Formulary Exclusions by Commercial National Payers, Oncology Products, 2018–2024 | |||
| Reason for Exclusion | |||
| Year | Generic/Biosimilar Alternative | Preferred Brand Alternative | Total |
| 2018 | 4 | 0 | 4 |
| 2019 | 10 | 6 | 16 |
| 2020 | 15 | 22 | 37 |
| 2021 | 33 | 34 | 67 |
| 2022 | 60 | 34 | 94 |
| 2023 | 76 | 40 | 116 |
| 2024 | 92 | 42 | 134 |
| Source: Thiesen J, Glass R, Lamprecht C. Access Challenges in the Cancer Patient Journey. IQVIA August 2024. | |||
Currently, 14 oncology biosimilars are approved by the FDA across the three drug categories. Based on the findings from the latest IQVIA data, covering 50 months postlaunch, bevacizumab biosimilars control 86% of the category, followed by biosimilar rituximab, which accounts for 78% of the marketshare in that category. Trastuzumab is a bit more complex, with biosimilars making up a 72% market share (a newer subcutaneous version of Herceptin®, which is not subject to biosimilar competition, may account for portion of the remainder).
Despite the potential of white bagging in this category, virtually all (98.5%) of medical oncology products continued to be purchased and reimbursed through the buy-and-bill system. Products that are obtained in this way, according to IQVIA, are more directly influenced by the economics of a physician practice, which generally favor discounts over rebates.
The researchers’ analysis of five national, commercial formularies revealed that the reference product was disadvantaged (if not excluded from coverage) relative to at least one biosimilar for each of the three oncology categories. Preferred coverage of these biosimilars has increased substantially since 2022.
For other oncology products, particularly oral medications, they report that patients face difficult coverage barriers: In only 10% of cases do patients insured by a commercial payer and 23% of Medicare eligibles (standard Medicare, not Medicare Advantage) receive approvals on their initial attempt. For commercial payers, patients seeking an innovator product are faced with formulary exclusions in 17% of attempts, prior authorization or step edit rejections in 40%, or a rejection based on quantity limit or too-rapid refill in 33%. Ultimately, 30 days of appeal or persistence led to a prescription fill rate of 50% for these claims.