ORLANDO, FLA. -- Adding the antiangiogenic agent bevacizumab to standard chemotherapies for lung, breast, and colorectal cancer produced significant survival gains in phase III trials reported at the annual meeting of the American Society of Clinical Oncology.
The results were hailed both as a step into the mainstream of cancer treatment for targeted agents and as an advance likely to change the standard of care for these leading forms of cancer.
The lung cancer results were particularly striking. Although the use of bevacizumab was associated with a modest 2-month gain in median overall survival, this represented an improvement of 30% for the leading cancer in the United States. At 1 year, slightly more than half (51.9%) of the patients given bevacizumab (Avastin)--but only 43.7% of the control group--were still alive.
"This is the first randomized trial in the last 10 years to show survival advantage in patients with untreated metastatic disease, and the first trial with a targeted agent that has shown survival advantage in combination with chemotherapy," principal investigator Alan B. Sandler, M.D., said in a plenary session report.
Bevacizumab, a monoclonal antibody, blocks vascular endothelial growth factor (VEGF), preventing the growth of blood vessels that feed tumors. The Food and Drug Administration approved the drug last year for the treatment of advanced colorectal cancer when used in combination with a chemotherapy regimen consisting of irinotecan plus 5-fluorouracil (5-FU) and leucovorin.
The antiangiogenic strategy, proposed in 1971 by Judah Folkman, M.D., of Children's Hospital Boston (N. Engl. J. Med. 1971;285:1182-6), was doubted for decades by many in the oncology community. That began to change in 2003, with the report of a 5-month survival advantage with the addition of bevacizumab to standard therapy for advanced colorectal cancer.
Genentech Inc., the manufacturer of Avastin, provided support for the studies presented at the ASCO meeting on treating lung, breast, and colorectal cancer.
As reported by Dr. Sandler of Vanderbilt University Medical Center in Nashville, Tenn., the Eastern Cooperative Oncology Group (ECOG) tested bevacizumab in 434 patients receiving a standard first-line regimen of paclitaxel and carboplatin for untreated stage III or IV nonsquamous, non-small cell lung cancer. A control group of 444 patients received only the standard treatment.
At the most recent follow-up, median overall survival had reached 12.4 months for patients in the bevacizumab arm, compared with 10.2 months for the control group. The bevacizumab arm also had a higher response rate (27%, vs. 10% in the control group) and longer median time to cancer progression (6.4 months, vs. 4.5 months in controls.) At 1 year, 14.6% of the bevacizumab arm but only 6.4%...