Background: Rituximab (RTX) is an anti-CD20 monoclonal antibody that is used to treat various conditions in cancer, rheumatoid arthritis (RA), and multiple sclerosis (MS). Although RTX has been used in the United States for almost 3 decades, questions remain regarding its real-world utilization and effectiveness.
Objective: To describe the state of observational research and real-world evidence evaluating RTX in oncology, RA, and off-label use in MS.
Methods: A broad search was conducted in MEDLINE, Embase, and CINAHL covering the period of January 2010 to June 2022. Two reviewers independently screened all identified records for each disease category (cancer, RA, MS) beginning with title review, followed by abstract, and full-text review to identify relevant publications to include in the final analysis. Data were extracted and summarized for each disease based on overall trends, similarities, and differences across included studies and stratified by disease state.
Results: A total of 260 studies met eligibility criteria, with 79 studies for the RA cohort, 144 for cancer, and 37 for MS. Across all disease cohorts, most studies (n = 189; 72.7%) were retrospective. 171 (65.8%) studies used hospital or electronic health record data as their data source and 65 (23.2%) used registry databases. Most studies (n = 153; 58.8%) assessed the effectiveness of RTX measured by disease-specific endpoints, followed by safety (n = 60; 23.1%), treatment patterns (n = 32; 12.3%), and descriptive analyses assessing treatment adherence and economic burden of disease (n = 16; 6.2%). Although safety was not the primary outcome for most studies, the majority of studies across all disease states still reported some form of safety measure. Conclusive statements on RTX's benefit varied across disease states, with MS having the most (n = 30; 81.1%) studies suggesting the drug's positive benefit. There were limited studies assessing RTX use, associated economic burden, and biosimilar switching.
Conclusions: The findings underscore the need for health care providers to better understand the treatment landscape and utilization of RTX, particularly in terms of patient selection, timing of initiation, and long-term outcomes. Real-world evidence can help support health care decisions and treatment using rituximab.