Data published for the first time today in the leading Journal of Clinical Oncology showed that the unique new cancer drug Avastin keeps cancer under control for a significantly longer duration, even when used in a group of elderly patients with advanced colorectal cancer who are too sick to tolerate traditional aggressive chemotherapy.
Avastin (bevacizumab, rhuMAb-VEGF), when added to a less aggressive form of chemotherapy, prolonged the time the cancer was not growing by an extra four months compared to chemotherapy alone (a 67% increase in progression-free survival).
"The additional four months of median survival that Avastin offers is of significant clinical benefit for these patients, who are unable to be treated with other more aggressive traditional chemotherapy combinations," said Dr Fairooz Kabbinavar, lead study investigator and Associate Professor at the UCLA School of Medicine, Los Angeles, USA. "In my opinion, these data indicate that Avastin should be a part of standard therapy for this group of frail and elderly patients, who currently have limited chemotherapy treatment options."
"This is an important study as it is the third clinical trial in which Avastin has shown a major benefit when combined with chemotherapy to treat advanced colorectal cancer. The growing body of evidence shows that Avastin not only provides valuable clinical benefit in first- and second-line settings and with different chemotherapy regimens, but is also well tolerated by a wide group of patients receiving treatment for their advanced disease," said Stefan Manth, Head of Roche Oncology.
Colorectal cancer is the third most commonly reported cancer with 945,000 new cases worldwide each year. It is estimated that over 50% of people diagnosed with colorectal cancer will die of the disease.
A total of 209 patients, over 65 years old and/or too unfit to receive a more aggressive chemotherapy, irinotecan, were randomised to receive a chemotherapy combination they could better tolerate (5-fluorouracil and leucovorin) with or without Avastin, in the first-line setting. The Phase II study showed that progression-free survival was significantly increased in the Avastin group (9.2 months vs. 5.5 months) compared to those treated with chemotherapy alone. Overall survival showed an improvement in the Avastin group (median, 16.6 months vs. 12.9 months) as did the response rates (26.0% vs. 15.2%) and the duration of response (9.2 months vs. 6.8 months).
Results from the pivotal Phase III study published in the New England Journal of Medicine demonstrated significantly longer survival in patients with previously untreated advanced colorectal cancer. The study, in which more than 900 patients participated, showed that Avastin plus chemotherapy increased overall survival by nearly five months (20.3 months vs. 15.6 months) compared to chemotherapy alone. The Phase III trial conducted by Eastern Cooperative Oncology Group (ECOG) also showed a significant increase in survival in patients with advanced colorectal cancer (12.5 months vs. 10.7 months) when Avastin was used in combination with a standard oxaliplatin-containing chemotherapy regimen, compared to chemotherapy alone. Patients receiving Avastin plus chemotherapy had a 26 percent reduction in the risk of death (hazard ratio of 0.74).
Avastin is the first treatment that inhibits angiogenesis - the growth of a network of blood vessels that supply nutrients and oxygen to cancerous tissues. Avastin targets a naturally occurring protein called VEGF (Vascular Endothelial Growth Factor), a key mediator of angiogenesis, thus choking off the blood supply that is essential for the growth of the tumour and its spread throughout the body (metastasis).
Avastin received fast-track approval by the US Food and Drug Administration (FDA) and was launched in the US in February 2004. In January 2005, the European Commission approved Avastin for the first-line treatment of patients with metastatic carcinoma of the colon or rectum in combination with the chemotherapy regimens of intravenous 5-fluorouracil/folinic acid or intravenous 5-fluorouracil/folinic acid/irinotecan.