Around 7,500 women are diagnosed with ovarian cancer in the UK each year. This makes ovarian cancer the 6th most common cancer in women. It is a cancer that spreads early, often with minimal symptoms, meaning that most women are diagnosed at an advanced stage. Of women that are diagnosed with stage 4 ovarian cancer, only 5% will survive for 5 years or more after diagnosis.
The standard of care for the treatment of ovarian cancer includes a combination of surgery to remove the tumour and chemotherapy, either before surgery to shrink cancer cells, or after surgery to destroy remaining cancer cells. Despite this treatment advanced ovarian cancer recurs in over 80% of women.
Opportunities to improve ovarian cancer survival
The NCRI Gynaecological Group identified that the poor prognosis and high recurrence rate provided an opportunity to improve treatment for women with advanced ovarian cancer.
The ICON7 trial was led and designed by the NCRI Gynaecological Group and Ovarian Cancer Subgroup, in collaboration with other International Ovarian Cancer Trials Groups. The NCRI Gynaecological Group includes a range of experts from different research disciplines. During the design of the ICON7 trial the group decided on the populations that should be involved. In addition they also decided the chemotherapy scheduling to be used and the dose and duration of other drug treatments that should be tested.
The ICON7 researchers wanted to know if giving Bevacizumabin combination with and then continuing after chemotherapy for up to 1 year, would be better than chemotherapy alone. Bevacizumabin is a monoclonal antibody that works by blocking the growth of new blood vessels (an antiangiogenic effect). The aim of this trial was to find out if adding Bevacizumab to chemotherapy could delay recurrence of ovarian cancer.
Developing a strategic portfolio of ovarian cancer trials
While the final results of the ICON7 trial were awaited, the NCRI Gynaecological Group addressed another unanswered question. This related to the scheduling (frequency) of chemotherapy. Evidence from a previous study in Japan suggested having smaller doses of chemotherapy more frequently might increase survival. Although it might also increase side-effects. The ICON8 trial compared the weekly scheduling of chemotherapy to the standard three weeks regimen. This trial showed that in European women, weekly chemotherapy was no more effective in controlling ovarian cancer. The treatment did also cause more side-effects. These results were reported in The Lancet. The researchers continue to follow-up to see if there is any difference in how long women in any of these groups live.
The final results of the original ICON7 trial showed that, in a higher risk subgroup of women, adding Bevacizumab to chemotherapy treatment improved outcomes and consequently overall survival was extended by 4.8 months. These results were reported in The New England Journal of Medicine and The Lancet Oncology.
This knowledge informed the design of a third trial, ICON8B, which is ongoing. This study will evaluate the combination of Bevacizumab with different chemotherapy scheduling regimes in women with advanced ovarian cancer.
A better way to treat women with ovarian cancer
The ICON7 trial supports the findings of other trials investigating Bevacizumab that have been published. The results from the ICON7 trial have influenced routine clinical practice. Bevacizumab is now available to patients in England with poor-prognosis ovarian cancer through the NHS Cancer Drugs Fund. This is the first new drug that has improved outcomes for women with untreated ovarian cancer in 17 years.
The International ICON7 trial offered a new treatment option, bevacizumab, for women with advanced ovarian cancer. It has been an important first step in beginning to personalise the care that we offer our patients.
Dr Shibani Nicum, Consultant Medical Oncologist, The Cancer Centre, Oxford and Chair of the NCRI Gynaecological Group