From the 2022 HVPA National Conference
Maher Alhaja PharmD (UCSF Medical Center), Candy Tsourounis PharmD, Hansen Ho PharmD, Richard Fong PharmD
Background
Bevacizumab-awwb and bevacizumab are vascular endothelial growth factor (VEGF) inhibitors that are commonly combined with other oncolytic agents for the treatment of various malignancies. Bevacizumab-awwb is the first biosimilar of bevacizumab to be licensed in the United States. Real-world outcomes of biosimilar use are limited, particularly for oncologic indications. In patients with non-small cell lung cancer, bevacizumab-awwb and bevacizumab demonstrated similar clinical efficacy, safety and pharmacokinetic profiles. However, bevacizumab-awwb outcomes in other cancer subtypes are lacking. Moreover, there are no studies evaluating the financial impact of using biosimilar bevacizumab as an alternative to bevacizumab through a direct cost comparison in a real-world population.
Objective
The purpose of this study is to compare the safety and financial impact outcomes associated with the utilization of biosimilar bevacizumab-awwb vs bevacizumab.
Methods
This is an IRB approved, single-center, retrospective cohort study included patients with cancer diagnoses age ≥ 18 years who were initiated on bevacizumab-awwb or bevacizumab between June 2019 and May 2021. Eligible patients for bevacizumab-awwb treatment must have been naïve to bevacizumab treatment. Patients switching from bevacizumab to bevacizumab-awwb or participating in clinical trials were excluded. Common terminology criteria version 5 for adverse events was used for safety outcomes assessment. The primary safety outcome was new-onset, grade ≥ 2+ hypertension (HTN). The secondary safety outcomes include grade ≥ 2+ proteinuria, hemorrhage, and gastrointestinal perforation. Another secondary outcome was the cost saving of biosimilar utilization as compared to the reference product using the average wholesale price for drug acquisition.
Results
In this study, 377 patients were included; 200 Bevacizumab patients and 177 Bevacizumab-awwb patients. There were 11 cancer types with similar baseline characteristics among both group except for ovarian cancer that was higher in the bevacizumab arm and hepatocellular carcinoma that was higher in the bevacizumab-awwb arm. Although there was no significant difference in grade ≥ 2+ HTN, initiation of new antihypertensive therapy was found to be higher in the bevacizumab arm (p = 0.002). Grade 2 proteinuria was observed to be lower in the Bevacizumab-awwb arm (p = 0.01). There were no significant differences in other safety outcomes. In year of 2020 bevacizumab-awwb utilization accounted for 34% vs 66% of bevacizumab orders saving $166,894. If bevacizumab-awwb utilization increased to 75%, there is a potential for saving $403,367 per year.
Conclusion
In this real-world analysis, bevacizumab-awwb demonstrated a comparable safety profile to bevacizumab in regards to grade ≥2+ hypertension, proteinuria, hemorrhage and gastrointestinal perforation regardless of primary cancer type. Replacing Bevacizumab for Bevacizumab-awwb can significantly lower acquisition costs for health systems.
Clinical Implication
Demonstrating that bevacizumab-awwb and bevacizumab products have a similar safety profile in a wide range of cancer patients, have the potential to broaden treatment options, lower acquisition costs, and improve patient access to a vital therapy.
