Glioblastoma (GBM) is the most common primary malignant brain tumor that nearly 
always results in a bad prognosis. Temozolomide plus radiotherapy (TEM+RAD) is 
the most common treatment for newly diagnosed GBM. With the development of 
molecularly targeted drugs, several clinical trials were reported; however, the 
efficacy of the treatment remains controversial. So we attempted to measure the 
dose of the molecularly targeted drug that could improve the prognosis of those 
patients. The appropriate electronic databases (PubMed, MEDLINE, EMBASE, and the 
Cochrane Library) were searched for relevant studies. A meta-analysis was 
performed after determining which studies met the inclusion criteria. Six 
randomized, controlled trials (RCTs) were identified for this meta-analysis, 
comprising 2,637 GBM patients. The benefit of overall survival (OS) was hazard 
ratio (HZ), 0.936 [95% confidence interval (CI), 0.852-1.028]. The benefit with 
respect to progression-free survival (PFS) rate was HZ of 0.796 (95% CI, 
0.701-0.903). OS benefit of cilengitide was HZ of 0.792 (95% CI, 0.642-0.977). 
The adverse effects higher than grade 3 were 57.7% in the experimental group and 
44.1% in the placebo group (odds ratio, 1.679; 95% CI, 1.434-1.967). The 
addition of molecularly targeted drugs to TEM + RAD did not improve the OS of 
patients with GBM; however, it did improve PFS in patients treated by 
cilengitide who could not get improvement in OS. The rate of adverse effects was 
higher in the experimental group than in the placebo group.