Real-World Clinical Outcomes of Bevacizumab-awwb Biosimilar versus Bevacizumab Reference Product in Patients with Metastatic Colorectal Cancer

Background: Bevacizumab-awwb was the first biosimilar approved for cancer treatment in the USA. Limited information is available on the real-world comparative safety and effectiveness of bevacizumab biosimilars, especially for indications granted approval through extrapolation.

Objective: To evaluate the real-world outcomes of patients with metastatic colorectal cancer (mCRC) initiated on bevacizumab-awwb versus bevacizumab reference product.

Patients and methods: This was an observational, longitudinal cohort study of US adult patients with mCRC from four integrated care delivery systems who were newly initiated on bevacizumab-awwb between 1 July 2019 and 30 March 2020 or bevacizumab reference product between 1 July 2015 and 30 June 2018. Patients were followed until 1 year after treatment initiation, end of plan membership, or death, whichever occurred first. The primary outcome of overall survival (OS) was analyzed using a binary non-inferiority test with lower margin of 10% and adjusted Cox proportional hazards regression analysis to assess all-cause mortality if non-inferiority was met. Secondary outcomes included counts of doses received, treatment duration, all-cause hospitalizations, and incidence of serious adverse events.

Results: A total of 1445 patients initiated on either bevacizumab-awwb (n = 239) or bevacizumab reference product (n = 1206) were included in the analysis. The mean overall age was 60 ± 13 years, 46% of patients were female, and 51% were white. The OS rate was 72.8% and 73.1% for patients receiving bevacizumab-awwb and bevacizumab reference product, respectively (p < 0.01 for non-inferiority). The adjusted hazard ratio for mortality was 1.01 (0.77-1.33, p = 0.93). There were no statistically significant differences in secondary outcomes between the study groups.

Conclusions: These findings suggest that bevacizumab-awwb is as effective and safe as bevacizumab reference product for the real-world treatment of mCRC.