Bevacizumab for recurrent glioblastoma: a systematic review and meta-analysis

The phenomenon is that few randomized control trials (RCTs) directly compared the effects of bevacizumab with other types of standard treatments for recurrent glioblastoma (GBM). We conducted a systematic review and meta-analysis to assess the efficacy of bevacizumab in recurrent GBM patients.

We searched electronic databases (Medline, Embase, and Web of Science) contrasting the bevacizumab with standard treatments up to May 2021. For the continuous outcomes of median progression-free survival (PFS) and median overall survival (OS), we summarized the mean difference (MD) as the effective index. We used relative risk (RR) to estimate the data with a random-effects model to get the outcomes of objective response rate (ORR), 12-month OS, 6-month PFS, and any mentioned adverse events.

A total of 807 patients in 5 RCTs included into our systematic review and meta-analysis. The results showed bevacizumab could provide benefits of the ORR (RR, 2.67; 95% CI: 1.14-6.26, p = 0.02), median PFS (MD, 1.12 months; 95% CI: 0.35-1.90 months, p = 0.005), but not the median OS (MD, -0.19 months; 95% CI: -1.37-0.99 months, p = 0.75). Whereas the rates of the secondary outcomes of interest were similar between the bevacizumab group and control group, including 6 month-PFS (RR, 1.23; 95% CI, 0.82-1.84, p = 0.32) and 12 month-OS (RR, 0.93; 95% CI, 0.79-1.09, p = 0.36). As for adverse events, patients with bevacizumab showed higher rates of grade 3/4 and any grade hypertension compared with those with standard treatments (RR, 3.71; 95% CI: 1.17-11.76, p = 0.03; RR, 2.68; 95% CI: 1.26-5.76, p = 0.01, respectively).

This study provides clear proof of the beneficial effects of bevacizumab treatment in recurrent GBM patients. The only observed adverse event was grade 3/4 or any grade hypertension.