At the primary data analysis after a median follow-up of 19.4 months, the median progression-free survival was 19.0 months with the addition of bevacizumab, which was significantly longer than the 17.3-month progression-free survival with standard chemotherapy alone.
Thus, the addition of bevacizumab prolonged progression-free survival by approximately 2 months. In addition, it increased the overall rate of treatment response by 19%, with a complete or partial remission rate of 67%, compared with 48% in the control group, Dr. Perren and his colleagues said (N. Engl. J. Med. 2011;365:2484-96).
The benefit of bevacizumab treatment was greatest in patients at the highest risk for cancer progression. Median progression-free survival was 15.9 months in this subgroup of patients who received bevacizumab, compared with only 10.5 months for those who did not.
Overall survival cannot yet be determined in this study, and is expected to be calculated and reported in 2013. "Some will argue that final overall survival data are needed before the results can be fully interpreted," the investigators noted.
Adverse events of grade 3 or higher were reported in 66% of the women who received bevacizumab and in 56% of the control group. The monoclonal antibody appeared to be associated with increased rates of bleeding, hypertension (18% of patients receiving bevacizumab vs. 2% of the controls), thromboembolic events (7% vs. 3%), and gastrointestinal perforations (10 patients vs. 3 patients).
However, both study groups showed improved global quality of life on two EORTC (European Organisation for Research and Treatment of Cancer) QoL questionnaires, and differences between the two groups were not clinically significant.
The GOG study was funded by the U.S. National Cancer Institute and Genentech. The ICON7 study was funded by Roche (parent company of Genentech) and the U.K. National Institute for Health Research, through the U.K. National Cancer Research Network. Dr. Burger, Dr. Perren, and their associates reported numerous ties to industry sources.