Bevacizumab (Avastin) is the fourth targeted drug in recent years to help patients with advanced kidney cancer, a disease that historically has been difficult to treat. A final-stage, randomized trial presented at the ASCO annual meeting found that the combination of bevacizumab and interferon was more effective than interferon and placebo. Adding bevacizumab nearly doubled the time the disease took to progress - from 5.4 months to 10.2 months - without creating significant new toxicities.

Interferon was the standard treatment for advanced kidney cancer when the trial began. But last year three targeted drugs - sunitinib (Sutent), sorafenib (Nexavar), and temsirolimus (Torisel) - emerged as the first new kidney cancer medicines in two decades, changing the standard of care. The new results demonstrate for the first time that bevacizumab, which is approved for advanced colorectal and non-small-cell lung cancers, is also effective against kidney cancer.

"The benefits of bevacizumab and interferon were greater than we expected," said lead investigator Dr. Bernard Escudier of the Gustave Roussy Institute in France. "We now need studies to compare the different therapies." Bevacizumab will likely be tested as a single agent against the other therapies in the coming years, he said.

The response rate in the trial of 649 patients was 31 percent for the bevacizumab group compared with 13 percent for the placebo group. After an interim analysis showed a clear benefit, all patients were offered the bevacizumab combination. Preliminary data suggest that bevacizumab may prolong survival, but additional studies are needed.

Combinations of targeted therapies may be needed to achieve the maximum benefit for patients. Toward this end, an early-stage clinical trial presented at ASCO showed that some patients tolerated a combination of sunitinib and bevacizumab. As dosage information becomes available, the combination may be appropriate for phase II trials in metastatic renal cell carcinoma as well as other cancers, the researchers said.