Utilization, user characteristics, and adverse outcomes of bevacizumab products in oncology in a distributed research network.

Abstract

400 Background: Bevacizumab (Avastin), an anti-angiogenic agent, was approved for various oncologic indications in 2004 in the US. Two biosimilars, bevacizumab-awwb (Mvasi) and bevacizumab-bvzr (Zirabev), were on the market 2017 and 2019, respectively. Real-world data on adverse events for bevacizumab biosimilars is limited. Methods: We conducted a retrospective cohort study using the Biologics and Biosimilars Collective Intelligence Consortium (BBCIC) distributed database to evaluate utilization patterns, patient characteristics, and prespecified adverse events of interest for the originator bevacizumab relative to its biosimilars in oncology among users 21 years of age and older between January 1, 2010, to December 31, 2020. Oncology indications included colon, lung, and gynecologic (cervical, uterine, and ovarian) cancers. Adverse events (AEs) of interest were arterial thromboembolism (ATE), congestive heart failure (CHF), gastrointestinal perforation, stroke and acute myocardial infarction (AMI), and venous thromboembolism (VTE). The study analyzed biosimilars collectively, which include bevacizumab-awwb and bevacizumab-bvzr. Results: Both bevacizumab originator and biosimilar users for colon cancer were mostly male (55%), had a mean age of 61 years, and a mean Charlson/Elixhauser combined comorbidity score from 7.0 to 8.0. Among patients with lung cancer users, 53% were female with an overall mean age of 64 years and comorbidity scores from 6.4 to 7.5. Patients with gynecologic cancers had mean age of 63 years, and comorbidity scores from 6.1 to 6.7. Overall, oncologic bevacizumab use increased by 19% over time. Of the 24,044 total episodes from 2010 to 2020, AEs included ATE (2,560 events, 11%), CHF (2,092 events, 9%), gastrointestinal perforation (2,858 events, 12%), stroke/AMI (399 events, 2%), and VTE (4,447 events, 19%). AE rates were comparable between the originator and biosimilars: 7% and 8% for ATE, 5% and 4% for CHF, 9% and 8% for gastrointestinal perforation, 0.6% and 1% for stroke and AMI, and 10% and 8% for VTE, respectively. From 2019 to 2020, biosimilar use increased from 6% to 49% of total bevacizumab utilization for patients with colon cancer, from 2% to 36% for patients with lung cancer, and from 2% to 38% for patients with gynecologic cancers. Conclusions: Bevacizumab utilization increased across all oncology indications evaluated during the study period. From 2019 to 2020, utilization for biosimilars relative to the originator increased. As there are limited data available on bevacizumab biosimilar use in real world settings, future research should be conducted to see if utilization for biosimilar products continues to rise as well as safety over time.