Background: Multiple low-cost biosimilars of bevacizumab are now available but their clinical efficacy has never been compared against the original (innovator) molecule in glioblastoma. The aim of the current analysis is to compare the overall survival (OS) in recurrent/progressive glioblastoma patients between the biosimilar and innovator molecules.

Materials and methods: Adult recurrent/progressive glioblastoma patients treated with bevacizumab from 1 July 2015 to 30 July 2019 were identified. These patients were either offered Bevacizumab innovator (Avastin, Roche) or biosimilar (BevaciRel: Reliance Life sciences or Bryxta: Zydus Oncosciences) depending upon the financial status and affordability of the patients. The primary endpoint of the study was OS, while progression-free survival (PFS) and adverse events were the secondary endpoints.

Results: There were 82 patients, out of which 57 received innovator and 25 received biosimilar bevacizumab. At median follow-up of 26 months, the median PFS was 3.66 (95% confidence interval (CI) 2.08 to 5.25) and 3.3 months (95% CI 2.38 to 4.21) in innovator and biosimilar group, respectively (Log-rank test p-value = 0.072). The hazard ratio (HR) for progression was 0.61 (95% CI 0.35 to 1.05; p-value = 0.075). At the time of data cut-off, the median OS was 5.53 (95% CI, 5.07 to 5.99) versus 7.33 months (95% CI, 5.63 to 9.03) in innovator and biosimilar group, respectively (Log-rank test p-value = 0.51). The HR for death was 1.21 (95% CI, 0.67 to 2.17; p-value = 0.51). The adverse events and safety profiles were comparable between the two groups.

Conclusion: In the recurrent/progressive glioblastoma patients, both innovator and biosimilar bevacizumab seem to have similar safety and clinical efficacy.