Study: Avastin Ups Survival for Colorectal Cancer Patients by 50 Percent

The experimental drug Avastin (bevacizumab) used in combination with chemotherapy increases the chances of survival for advanced colorectal cancer patients by 50 percent, researchers reported at the American Society of Clinical Oncology annual meeting.

Dr. Herbert I. Hurwitz of Duke University Medical Center said that in a multicenter study of more than 800 patients, those treated with Avastin plus chemotherapy had a median survival of 20.3 months compared to 15.6 months for patients treated with chemotherapy alone.

The median time to disease progression increased from 6.2 months for the patients on chemotherapy alone to 10.6 months for those on Avastin plus chemotherapy arm, Hurwitz reported.

Avastin plus chemotherapy was also shown to improve overall response rates from 35 percent in the group receiving chemotherapy alone to 45 percent with Avastin plus chemotherapy, and the duration of response increased from 7.1 months with chemotherapy to 10.4 months with Avastin plus chemotherapy.

"The results of this Phase III study showed that adding Avastin to standard chemotherapy resulted in a significant improvement in how long metastatic colorectal cancer patients lived, how well their tumors shrank, and how long their tumor growth remained under control," said Hurwitz.

"Importantly, these clinical benefits were seen in all groups of patients -- young and old. In addition, there were very few side effects, and those observed in this study were generally mild and manageable, especially compared to standard chemotherapies," Hurwitz added.

Avastin is one of a new class of cancer-fighting drugs designed to inhibit a protein known as vascular endothelial growth factor (VEGF), which plays a critical role in formation of new blood vessels to the tumor and stimulates growth of new blood vessels.

The anti-angiogenisis drug slows tumor growth and the spread of cancer by cutting off its supply of blood and oxygen.

"Our study offers important proof of the philosophy that targeting a tumor's blood supply can, in fact, inhibit the tumor's ability to proliferate," said Hurwitz.

Other Sources: ASCO, Genentect