Results from a recent Phase III trial indicate that the addition of the targeted therapy Avastin® (bevacizumab) to the chemotherapy drug Gemzar® (gemcitabine) does not improve survival in advanced pancreatic cancer. These findings were reported in the Journal of Clinical Oncology.
Pancreatic cancer is one of the deadliest forms of cancer. Each year, approximately 43,000 people are diagnosed with pancreatic cancer in the United States and more than 37,000 die from the disease. The disease is often diagnosed at an advanced stage, and improved approaches to early detection and treatment are important research priorities.
Gemzar, used alone or in combination with other drugs, has been a standard chemotherapy drug for the treatment of advanced pancreatic cancer for some time. Avastin is a targeted therapy that blocks a protein known as VEGF, which plays a key role in the development of new blood vessels. Findings from a previous Phase II study indicated that the combination of Gemzar and Avastin may be active in advanced pancreatic cancer.
Researchers involved in a recent Phase III trial further investigated whether the combination of Gemzar and Avastin could improve survival among patients with advanced pancreatic cancer. Patients in the study had not been previously treated for advanced disease. All patients were given Gemzar three times during each 28-day treatment cycle. One group also received two separate doses of Avastin during each 28-day cycle, while another group was given a placebo. Treatment was stopped if patients experienced a worsening of their cancer or unacceptable side effects. Five hundred thirty-five patients were treated.
· Median overall survival was not improved among those receiving Avastin compared with placebo: both groups survived to approximately six months.
· Median progression-free survival was approximately four months for the Avastin group and almost three months for the placebo group.
· Overall response rates were 13% for those receiving Avastin and 10% for placebo.
· Side effects were similar among both groups, with the exception of increased rates of high blood pressure and proteinuria (excess serum proteins in urine) in the Avastin group.
Despite indications from the previous Phase II trial that the addition of Avastin to Gemzar may improve survival in advanced pancreatic cancer, the researchers concluded that, based on these Phase III trial findings, the combination offers no survival advantage.
 Kindler HL, Niedzwiecki D, Hollis D, et al. Gemcitabine plus bevacizumab compared with gemcitabine plus placebo in patients with advanced pancreatic cancer: Phase III trial of the Cancer and Leukemia Group B (CALGB 80303). Journal of Clinical Oncology [early online publication]. July 6, 2010.