Increased Progression, Mortality Not Apparent After Halting Bevacizumab
A retrospective meta-analysis of 5 multicenter, randomized controlled trials of bevacizumab in patients with a variety of cancers showed that the time to disease progression or death was similar in the bevacizumab and the placebo-treated groups after bevacizumab was discontinued (J Clin Oncol. 2011;29:83-88).
Some studies have suggested that tumors grow more quickly and metastasize after antiangiogenic agents such as bevacizumab are withdrawn. To test this theory, an international team of investigators analyzed data from 5 double-blind, randomized phase 3 studies of patients with various metastatic cancers.
In a pooled analysis, the median time from discontinuation to progression progression or death was 3 months in the placebo group and 4 months for those treated with bevacizumab. Mortality rates were similar for both groups up to 210 days after drug discontinuation, and there were similar patterns of disease progression in both groups.
The researchers acknowledge the difficulties inherent when analyzing disparate studies, diseases, and small numbers of patients.