ASCO 2011 Annual Meeting, 3—7 June 2011, Chicago
Suggested benefit of bevacizumab for newly diagnosed ovarian cancer patients at high risk of recurrence
Dr Gunnar Kristensen – Norwegian Radium Hospital, Oslo, Norway
I’ve been talking about an interim analysis of overall survival from the ICON7 study. The ICON7 study is a randomised phase III study to evaluate the benefit of adding bevacizumab to standard chemotherapy for ovarian cancer. The endpoints of the study are progression free survival and overall survival; today we have presented an update of progression free survival. The first results on progression free survival were presented at ESMO last year but now we have done an update and this update on progression free survival shows that there is a gain in time to progression for this patient group using bevacizumab. For overall survival we see that there is a trend to prolonged survival in the group receiving bevacizumab. At this time it is a trend, but we have to remember that this is an interim analysis and the final results will not be due before 2013.
How did you define the group?
The total group of patients included in this study, there were 1528 women and they had all ovarian cancer or tubular cancer or peritoneal cancer. They underwent surgery and those who were recruited to the study, 90% of them had advanced ovarian cancer, meaning spread outside the ovaries or even outside the abdominal cavity, called stage 4. Additionally, we had 10% of the patients in the study had early stage disease, meaning disease just located to the ovaries but of especially high risk group, meaning a group where we know from before that this group of patients have a really high risk of recurrence; these are special histological types and so on. So that’s the total group of patients. Then we performed sub-group analysis on patients out of the whole group who have an especially high risk of recurrence and that is patients with advanced disease spread to the abdominal cavity where there is at least 1cm in diameter of tumour left after surgery, we have not been able to remove the tumour completely or nearly completely by surgery, or patients who have spread outside the abdominal cavity. So this high risk group of patients represent a sub-group where we have done a sub-group analysis. We have earlier presented that this really high risk group, in this group we see a higher degree of prolongation of progression than in the remaining patients. And in our overall survival analysis we see that there is a considerably longer prolongation of life using bevacizumab in this group than in the remaining group.
What are the potential clinical impacts?
To see the full impact of this treatment we should maybe wait for the final analysis of overall survival. We do see that there is a delay in time of progression overall and of special interest is that we see this major prolongation of time to death in the high risk group. In fact, in that group the prolongation of living years was 8 months, which is quite considerable.