Clinical outcomes with bevacizumab-containing and non-bevacizumab–containing regimens in patients with recurrent glioblastoma from US community practices

Abstract

This analysis evaluated the efficacy and safety of bevacizumab as monotherapy and with irinotecan for recurrent glioblastoma in community-based practices. Adult patients with bevacizumab-naive, recurrent glioblastoma initiating second-line treatment (July 2006–June 2010) were identified using McKesson Specialty Health/US Oncology Network health records. Overall (OS) and progression-free survival (PFS) estimates were analyzed through July 2011 and compared for bevacizumab and non-bevacizumab regimens using the log-rank test. An adjusted Cox proportional hazards model assessed the effects of patient and treatment characteristics on outcomes. The analysis identified 159 patients initiating second-line treatment with a bevacizumab-monotherapy (n = 57), bevacizumab-combination (n = 79), or non-bevacizumab (n = 23) regimen. Patient characteristics were generally similar across groups. In the Cox analyses, OS (hazard ratio [HR] 0.51 [95 % confidence interval (CI) 0.31–0.82]; univariate medians: 8.86 vs. 5.19 months) was significantly longer with bevacizumab-containing regimens. Median PFS was longer with bevacizumab-containing regimens, but did not reach statistical significance (HR 0.64 [95 % CI 0.38–1.09]; univariate medians: 7.00 vs. 4.00 months). Analyses showed that each bevacizumab treatment group relative to non-bevacizumab had a reduced risk of death (bevacizumab-monotherapy regimen: HR 0.56 [95 % CI 0.31–1.03] and bevacizumab-combination regimen: HR 0.34 [95 % CI 0.21–0.68]). Patients receiving the bevacizumab-combination regimen trended toward longer OS and PFS than those receiving the bevacizumab-monotherapy regimen. Rates of bevacizumab-related toxicities were consistent with clinical trial reports.