Related Pages Treatment Referral Center Trial of Bevacizumab A collection of material about a clinical trial that is evaluating bevacizumab (Avastin™), an investigational antiangiogenic agent, for patients with advanced colorectal cancer who are no longer benefiting from standard treatments. Colon and Rectal Cancer Home Page NCI's gateway for information about colon and rectal cancer. Highlights from ASCO 2003 A collection of links to material summarizing some of the important clinical trial results announced at the 2003 annual meeting of the American Society of Clinical Oncology (ASCO).

Keywords
Colorectal cancer; Avastin; bevacizumab; anti-angiogenesis; VEGF

Summary
Patients with newly diagnosed metastatic colon cancer who received the therapeutic agent bevacizumab (Avastin™) along with the chemotherapy combination known as IFL had substantially longer overall survival times than patients who received IFL but with a placebo instead of bevacizumab. With these results, bevacizumab becomes the first anti-angiogenesis agent to prove effective in a randomized Phase III trial.

Source
American Society of Clinical Oncology (ASCO) annual meeting, Chicago, June 1, 2003. Final results subsequently published in the June 3, 2004, issue of the New England Journal of Medicine (see the journal abstract).

Background
Bevacizumab works by blocking angiogenesis – the formation and growth of new blood vessels – by targeting a protein called vascular endothelial growth factor (VEGF). In addition to colon cancer, bevacizumab is now under study in several other diseases including renal cell cancer, prostate cancer, non-Hodgkins lymphoma, and many others.

Two other new agents, oxaliplatin and cetuximab (Erbitux®) have also recently shown benefit in randomized trials for patients with advanced and metastatic colorectal cancer. New trials are underway or being planned to compare these two agents and bevacizumab in various combinations.

The Study
About 800 patients with previously untreated metastatic colorectal cancer were randomly divided into two groups. One group received IFL (also known as the Saltz regimen) plus bevacizumab while the other received IFL plus a placebo (a dummy substance). IFL consists of irinotecan, 5-fluorouracil (5-FU), and leucovorin.

Results
Patients who received IFL plus bevacizumab survived a median of 20.3 months while those on IFL plus placebo had a median survival of 15.6 months. Cancer did not progress for a median of 10.6 months in the bevacizumab group compared to 6.2 months in the other group. Tumors shrank by at least half in 45 percent of the patients who received bevacizumab versus 35 percent in the other group.

“This is the first Phase III trial of an anti-angiogenesis strategy to treat human cancer,” said lead investigator Herbert Hurwitz, M.D., of Duke University Medical Center. “The results are clinically meaningful.”

Side effects in the two groups were comparable with one exception: hypertension was more frequent in the bevacizumab group. However, it was treated effectively with medication. Also reported as a possible side-effect of bevacizumab was a rare but life-threatening complication of perforation of the bowel.

Limitations
The results apply only to one group of colorectal cancer patients – those with metastatic disease that has not been previously treated. Bevacizumab’s effect on other patients is being explored.

Also, bevacizumab is an investigational agent that is only available through clinical trials.

Other clinical trials have shown that a different treatment approach known as FOLFOX (oxaliplatin plus fluorouracil plus leucovorin ) produces a similar improvement in survival compared to IFL, and is currently used as the standard therapy for colorectal cancer patients.

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