Reassessing the efficacy of bevacizumab in newly diagnosed glioblastoma: a systematic review and external pseudodata-based analysis

First-line use of Bevacizumab for glioblastoma (GBM) was evaluated in two Phase III randomized controlled trials (RCT), demonstrating an impact on progression-free survival (PFS) but not overall survival (OS). However, the crossover events of these trials raised concerns regarding the reliability of this latter analysis. In this study, we conducted an external control-based reassessement of the bevacizumab efficacy in newly diagnosed GBM (ndGBM) against the standard Stupp protocol. A systematic review of literature was conducted to identify the Phase III RCTs in ndGBM incorporating the Stupp protocol as an arm. For the selected studies, we extracted individual patient survival pseudodata of the Stupp protocol arm by digitizing the Kaplan-Meier plots. A comprehensive pipeline was established to select suitable control studies as external benchmarks. Among the 13 identified studies identified in our systematic review, 4 studies resulted as comparable with the AVAglio trial and 2 with the RTOG 0825. Pooled individual patient pseudodata analysis showed no differences in terms of OS when bevacizumab is added to the Stupp protocol. The external controlled-based reassessment of the bevacizumab treatment in ndGBM confirmed its lack of efficacy in extending OS. Our study includes a summary table of individual patient survival pseudodata from all Phase III RCTs in ndGBM employing the Stupp protocol and provides a pipeline that offers comprehensive guidance for conducting external control-based assessments in ndGBM.