Retrospective Indication-Matched Cohort Study of Reference Product and Biosimilar: Bevacizumab Versus...

Introduction: Due to the abbreviated approval pathway and extrapolation to non-studied indications, an increased importance is placed on post-marketing surveillance of biosimilars to supplement existing evidence and enhance patient and provider confidence. Bevacizumab-awwb (ABP 215, Mvasi) was the first biosimilar approved to bevacizumab (Avastin), a recombinant humanized monoclonal IgG1 antibody that inhibits the vascular endothelial growth factor (VEGF). Purpose: To evaluate utilization, safety, and financial outcomes of bevacizumab-awwb compared to bevacizumab at a national cancer institute (NCI)-designated cancer center. Methods: A single center, retrospective, 1:1 indication-matched cohort study of adult patients who received bevacizumab or bevacizumab-awwb between October 1, 2019 and October 1, 2020 was performed. Thirty-four patients received bevacizumab-awwb during the study period and were matched by indication to 34 randomly selected patients who received bevacizumab. Indications for both groups included: colorectal cancer (n = 19), gynecologic cancer (n = 10), glioblastoma (n = 3), hepatocellular carcinoma (n = 1), and lung cancer (n = 1). Results: Baseline and medication utilization characteristics were similar for this indication-matched cohort of 68 patients receiving bevacizumab-awwb or bevacizumab. Patients in the bevacizumab group had a higher proportion of public payer coverage (64.7% vs 38.2%, P = .029). A higher proportion of patients in the bevacizumab-awwb group remained on active treatment at the end of the study period (52.9%) as compared to the bevacizumab group (35.3%); however, differences in final treatment status and reasons for discontinuation were not statistically significant (P = .218). Rates of worsened hypertension (44.1% vs 44.1%) and worsened proteinuria (38.2% vs 23.5%, P = .077) were common in both groups. Grade 3 adverse drug events in the bevacizumab group included: gastrointestinal perforation (n = 1), gastrointestinal bleed (n = 1), hypertension (n = 2), and venous thromboembolism (n = 2). Grade 3 adverse drug events in the bevacizumab-awwb group included: epistaxis (n = 1), gastrointestinal bleed (n = 1), hypertension (n = 1), intracerebral hemorrhage (n = 1), venous thromboembolism (n = 3), and arterial thromboembolism (n = 1). One patient in the bevacizumab-awwb group experienced grade 4 hypertension. Median drug cost per dose and per milligram for bevacizumab-awwb was less than bevacizumab, representing a 15.8% and 12.1% discount, respectively. Conclusion: Utilization and safety outcomes were similar for this indication-matched cohort of 68 patients receiving bevacizumab or bevacizumab-awwb across a wide range of disease states.