Records show the biosimilar for bevacizumab was used to treat both new patients and those already receiving care with the reference product.
A retrospective study characterized the real-world use of the biosimilar bevacizumab-awwb (Mvasi) for metastatic colorectal cancer (mCRC) during the first year after it entered the market in the United States. The study authors said their analysis of patient records suggested US oncologists adopted the bevacizumab biosimilar in clinical practice for mCRC for both new patients and those already being treated with the reference product.
Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor-A (VEGF), approved by the FDA for treating mCRC in 2004. Since then, the authors wrote, “bevacizumab has been an important biologic therapy in treating a range of solid tumor indications as the standard of care in oncology.” Mvasi was approved by the FDA in 2017 and entered the US market in July 2019 as the first bevacizumab biosimilar.
mCRC is an extrapolated indication for bevacizumab-awwb
Approval of Mvasi was based on a comparative clinical efficacy and safety study in patients with advanced non-small cell lung cancer. Metastatic colorectal cancer is one of multiple extrapolated indications for the biosimilar.
The investigators said the purpose of their study was to evaluate the real-world use of the biosimilar in mCRC. They noted, “the American Society of Clinical Oncology has underlined the importance of postmarketing evidence to enhance patient and provider confidence in biosimilars.”
Patient characteristics and treatment patterns
Data on 304 patients who received the biosimilar during the first year of its availability were derived from the ConcertAI oncology dataset. About half of patients (47%) were bevacizumab-naïve. Investigators found demographic and clinical characteristics “appeared comparable” between bevacizumab-naïve and bevacizumab-experienced patients, and the characteristics of the patient population were “generally consistent with those of the US CRC population.”
Seventy-eight percent of patients overall were treated with the biosimilar as first-line therapy, and 91% among bevacizumab-naïve patients. The median time from mCRC diagnosis to initiation of biosimilar therapy was 63 days (interquartile range 36-138 days). Among patients previously treated with the reference product, 83% were switched to the biosimilar in the same line of therapy without disease progression. Most bevacizumab-experienced patients (74%) switched to the biosimilar within 28 days of their last reference product infusion. Among patients who switched without disease progression, 83% switched within 28 days of their last reference product infusion. The authors said these data suggest “early acceptance” of the biosimilar by US oncologists for both new and existing patients with mCRC.
The investigators wrote that their first-year post-marketing analysis of bevacizumab-awwb use “provides timely data in a tumor type where clinical trial data are not available.” They added that they are currently collecting data for a 12-month safety and effectiveness study in mCRC to be published in the future.
Rhodes W, DeClue RW, Accortt NA, Jin R, Sandschafer D, Wertz D, Patel K. Real-world use of bevacizumab-awwb, a bevacizumab biosimilar, in US patients with metastatic colorectal cancer. Future Oncol. 2021;17(36):5119-5127. doi: 10.2217/fon-2021-0588.