Real-World Budget Impact of Listing a Biosimilar of Rituximab

Background: The approval of new biosimilars by national health agencies is expected to generate significant cost savings for health care systems. This is particularly the case with the biosimilar of rituximab approved for the Canadian market in 2019. However, several uncertainties remain regarding utilization of this agent. Objectives: To determine the proportion of total annual drug expenses for each indication for rituximab in the hospital setting and to determine potential savings related to introduction of a biosimilar. Methods: A budget impact analysis was performed through 3 real-world scenarios, based on data obtained from a large university teaching hospital for a 12-month period. Results: This study involved data for 420 patients. Annual expenses for rituximab for all indications represented 7.7% of total annual drug spending for the hospital, of which 5.0% was related specifically to indications approved by Health Canada. More than 6% of the annual drug expenses was attributable to the use of rituximab for oncologic indications, including 1.8% for uses not approved by Health Canada. Overall, each 10% reduction in the price of a biosimilar of rituximab (relative to the reference rituximab) would result in annual savings of about 0.8% of total drug expenses in the hospital if a biosimilar was used for all real-world indications, whether approved by Health Canada or not. Conclusions: The introduction of a biosimilar of rituximab to the Canadian market would generate significant savings. To properly assess the potential savings that this agent could generate in the limited budget environment of a hospital, it seems important to consider all of the indications for which it could be used.