Combined second-line treatment with Avastin® (bevacizumab) and standard chemotherapy extends survival in patients with advanced colorectal cancer who have received first-line combined Avastin treatment, according to the results of a large phase III study presented at the 2012 annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Illinois.
Avastin is an anti-angiogenic targeted therapy that blocks a protein known as VEGF. VEGF plays a key role in the development of new blood vessels. By blocking VEGF, Avastin deprives the cancer of nutrients and oxygen and inhibits its growth. Avastin’s effects on blood vessels may also improve the delivery of chemotherapy to the tumor. Multiple studies have shown that the addition of Avastin to standard chemotherapy improves outcomes among patients with metastatic colon cancer—and now, the results of this study confirm what physicians have long suspected, that extended Avastin treatment provides significant benefit for patients with advanced colorectal cancer.
Avastin (used in combination with standard chemotherapy) is already approved for first- and second-line treatment of advanced colorectal cancer, but this is the first randomized trial to evaluate the regimen in the second-line setting in patients who have previously been treated with it in the first-line setting. The study included 820 patients with metastatic, inoperable colorectal cancer who were treated with standard first-line chemotherapy and Avastin. After disease progression, patients were randomized to receive a different chemotherapy drug plus Avastin or chemotherapy plus placebo. The group that received Avastin experienced improved survival—overall survival was 11.2 months in the Avastin group, compared to 9.8 months in the placebo group and progression-free survival was 5.7 months in the Avastin group compared to 4.1 months in the placebo group. Treatment was well tolerated by patients in both arms.
The researchers concluded that extended Avastin treatment improves survival in patients with advanced colorectal cancer. They speculated that the results indicate that even when tumors become resistant to chemotherapy, they may not develop resistance to anti-angiogenic therapy—so switching chemotherapy drugs when the cancer progresses and continuing Avastin could make second-line treatment more effective.
Arnold D, Andre T, Bennouna J, et al. Bevacizumab (BEV) plus chemotherapy (CT) continued beyond first progression in patients with metastatic colorectal cancer (mCRC) previously treated with BEV plus CT: Results of a randomized phase III intergroup study (TML study). Presented at the 2012 annual meeting of the American Society of Clinical Oncology, June 1-5, 2012, Chicago, IL. Abstract CRA3503.