Retrospective cohort study of cancer biologics utilization after biosimilar entry and financial implications for payers and patients

Biosimilars are highly similar to originator biologics and were introduced to increase market competition, lower the prices of biologics, and expand patient access by improving affordability. By the end of 2024, three anticancer biologics have experienced biosimilar entry in the US: bevacizumab, rituximab, and trastuzumab. A retrospective cohort study using data from the Merative MarketScan commercial database and Medicare database from July 2019 to December 2024 examined price and market share trends and payer and patient cost after biosimilar entry. In this cohort study of 14 655 patient-drug pairs, compared with patients who only used originator biologics, those who used only biosimilars rendered $ 3829 lower mean monthly payer costs and $ 39.50 lower mean monthly patient out-of-pocket costs. After biosimilar entry, the average sale prices declined by an average of 3.8% annually. The authors conclude that results of this study suggest that exclusively using biosimilars has lowered financial burden for payers and patients.