Rituximab reference vs biosimilar utilization for oncology vs nononcology indications

Area of Science:

• Pharmacoeconomics and Health Economics
• Oncology and Hematology
• Immunology and Rheumatology

Background:

• Limited real-world data exist on rituximab biosimilar adoption across different indications compared to the reference product.
• Existing studies primarily focus on oncology, leaving a gap in understanding non-oncology use patterns.
• This study provides the first comprehensive analysis of the utilization of three US-approved rituximab biosimilars versus the reference rituximab.

Purpose of the Study:

• To compare the real-world utilization of rituximab biosimilars (rituximab-abbs, rituximab-pvvr, rituximab-arrx) against the reference product.
• To analyze adoption trends and patterns by indication (oncology vs. non-oncology), labeling (on-label vs. off-label), and healthcare setting (academic vs. nonacademic).

Main Methods:

• A comparative analysis using deidentified real-world data of rituximab and its biosimilar dispensations from December 2018 to February 2022.
• Data were extracted from Trisus Medication Compare, covering 28,025 encounters across 193 facilities.
• Primary outcome: rituximab reference vs. biosimilar utilization, stratified by indication, labeling, and treatment setting.

Main Results:

• Rituximab reference product showed higher initial dispensations for both oncology (78.4%) and non-oncology (88.3%) indications.
• Biosimilar utilization significantly increased from 0.01% in 2019 to 59.9% in 2021, while reference product use decreased.
• Higher biosimilar adoption was observed for on-label indications (67.7%) and in nonacademic settings (22.2%) compared to academic settings (10.3%).

Conclusions:

• Real-world evidence demonstrates a growing adoption of rituximab biosimilars over time.
• Biosimilar uptake is more pronounced for oncology indications and within nonacademic healthcare environments.
• These findings highlight evolving treatment landscapes and the increasing integration of biosimilars in clinical practice.