The final results from the ICON7 trial in ovarian cancer were published today in the Lancet Oncology. The results show that, taking the whole group of women taking part in the study, adding bevacizumab to standard chemotherapy did not improve survival. However, researchers found that adding bevacizumab did help the sub-group of women with high-risk ovarian cancer to live longer.
Ovarian cancer is the seventh most common cancer worldwide. In 2012, there were 238,700 new cases and 151,900 deaths from ovarian cancer across the world. Ovarian cancer is difficult to detect, meaning that women are often not diagnosed until the disease is at an advanced stage. Survival rates for ovarian cancer are poor and most women with advanced disease are not cured.
The ICON7 trial was launched in 2006. It looked at adding a drug called bevacizumab to standard chemotherapy for women who had recently been diagnosed with ovarian cancer. Bevacizumab is a ‘targeted therapy’ that works by blocking the development of new blood vessels, and therefore interfering with the tumour’s ability to grow and spread to other parts of the body.
1,528 women took part in the trial, from hospitals in 11 countries across Europe, Canada, Australia and New Zealand. The women were randomly allocated to one of two treatment groups:
The first results from the ICON7 trial were announced in 2010. The results were positive, showing that combining bevacizumab with standard chemotherapy improved progression-free survival (time without disease worsening or coming back). However, to fully assess a new treatment, we also need to look at whether it helps patients to live longer (overall survival). Researchers continued to follow-up the women who took part in ICON7 in order to answer this question.
The final results from ICON7 showed that the whole group of women receiving bevacizumab did not live longer overall than those in the group receiving no bevacizumab. However, for a subgroup of patients with high-risk disease (whose cancer was most likely to get worse or return) bevacizumab did make a difference. Researchers found that adding bevacizumab to standard chemotherapy helped women with high-risk disease to live 4.8 months longer, on average, than the women who did not receive bevacizumab.
On the whole, the bevacizumab treatment was safe and well tolerated in the women and side-effects were generally mild and manageable. There was also no difference found in quality of life between the women who received bevacizumab and the women who had chemotherapy alone.
The final results of ICON7 suggest that bevacizumab could be used selectively to help treat women with high-risk ovarian cancer. Researchers also found that the more advanced the cancer, the greater the positive effect of bevacizumab. This finding could help doctors to plan treatment for individual patients, although there are still questions to be answered about how bevacizumab could be used more widely (including when it is best used and how long for).
Bevacizumab is an expensive drug, so there are also questions about the cost-effectiveness of this treatment. Researchers are currently doing an economic analysis of the ICON7 findings and will publish their results separately.
The results of ICON7 are consistent with those of the GOG-218 trial of bevacizumab for ovarian cancer carried out in America.
The ICON7 trial was sponsored by the Medical Research Council and run through the Gynecologic Cancer Intergroup (an international cooperative group for clinical trials in gynaecological cancers). Funding for running costs was provided by the pharmaceutical company Roche. This trial was supported in the UK by the National Institute for Health Research Cancer Research Network (NCRN).