Avastin may help stall ovarian cancer

Two studies released in this week's New England Journal of Medicine suggest the drug Avastin may benefit some ovarian cancer patients.

The two studies found that adding Avastin to chemotherapy treatment can stall the growth of cancer by almost four months. Avastin, which has the generic name Bevacizumab, stops the growth of blood vessels that feed cancerous tumors, say researchers. However, it is still unclear if it will extend patients' lives.

Ovarian cancer is the fifth most common cancer for American women . According to the National Cancer Institute, 15,000 women in the United States die from it each year . It is frequently undetected until it has advanced to a late stage, making it the most fatal of all gynecological cancers.

While Avastin has been approved by the FDA for some cancers, including kidney, brain, and colon cancer, it has come under fire for its use in breast cancer treatment. It was initially approved for breast cancer treatment in 2006. But late last month, the FDA revoked Avastin’s approval for breast cancer because they felt the benefits did not outweigh the side effects. Avastin is produced by Genentech, a subdivision of Roche Pharmaceuticals.

The two studies were funded by Roche.

One study was led by the Gynecological Oncology Group and surveyed 1,873 women internationally who had been newly diagnosed with stage III or IV cancer. Women who received the drug as part of their chemotherapy regimen were found to increase their rate of progression-free survival, or the length of time before the cancer worsened, to 14 months. It was a four-month increase over patients who were just given the placebo and had a progression-free survival period of 10 months.

Dr. Robert Burger of the Fox Chase Cancer Center in Philadelphia was the lead author of the study. “This is a new paradigm in the treatment of this disease,” says Burger. He says that patients with Stage III or IV ovarian cancer “deserve to have this treatment as an option.”

The other study, led by the International Collaboration on Ovarian Neoplasms, looked at more than 1,500 women internationally. This study included women with less severe stages of cancer. Authors found women with the placebo had a 22-month progression-free survival period, versus 24 months for those on Avastin, for a two-month difference before the cancer worsened. However, when looking just at patients with stage III or IV cancer, the progression-free survival period for those on Avastin increased by over three months.

While Avastin can delay the growth of cancers, researchers were unable to definitively say how it impacts survival rates for patients. They say that it will still take a few more years of tracking before they can fully determine that. Full survival data is not expected until at least next year.

In addition, patients who did take Avastin in both studies did experience some side effects, including increased hypertension and tearing of the gastrointential wall. However, according to both studies, quality of life was not impacted by the side effects.

“I think this data is compelling. Improved control of disease is always a good endpoint, but living longer is a better endpoint,” says Dr. Joanne Mortimer, who sat on the FDA advisory committee looking at Avastin for the treatment of breast cancer. Mortimer, who is not connected to the studies, is a bit cautious. “Without increased survival rates, are the side effects worth it?”

Last week, the European Commission approved the use of Avastin in the treatment of ovarian cancer patients. However, Genentech says that based on the current findings of the studies, they will not ask the FDA to consider it for ovarian cancer treatment in the United States. They are still waiting for full survival data.