The overall tumor response rate for the patients who received bevacizumab plus chemotherapy was 27 percent, compared to 10 percent for patients who received chemotherapy alone. Progression-free survival was 6.4 months for the bevacizumab-plus-chemotherapy arm, compared to 4.5 months for chemotherapy alone.
Bevacizumab, which was approved last year for treatment of advanced colorectal cancer, binds to and interrupts the activity of the vascular endothelial growth factor (VEGF). VEGF's signals prompt the recruitment and growth of new blood vessels to provide tumors with the oxygen and nutrients they need to grow and spread. Interrupting that process destroys these vessels.
However, earlier studies with this drug among lung cancer patients found a serious risk of life-threatening bleeding, particularly among those with a type of cancer called squamous cell carcinoma. By excluding squamous cell cancers from the study, the risk of life-threatening bleeding was "substantially decreased," Sandler said.
The American Cancer Society estimates that more than 172,000 new cases of lung cancer will be diagnosed this year, and the disease will claim more than 163,000 lives. Of those, about 85 percent will be non-small cell cancers, and of that group, about 85 percent will fall in the non-squamous category. Patients with brain metastases were also excluded from the study, which account for about 10 percent of patients. "Even though this drug appears to benefit a subset of lung cancer patients, it is still a sizeable group of patients," Sandler said. The U.S. Food and Drug Administration has not yet considered bevacizumab for this potential new indication.
In addition to Sandler and colleagues at Vanderbilt-Ingram, the study presented at ASCO included co-authors from Dana Farber Cancer Center,
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Contact: Cynthia Floyd Manley
cynthia.manley@vanderbilt.edu
615-430-8320
Vanderbilt University Medical Center
13-May-2005