Cancer drug Avastin slows ovarian cancer progression, study shows

Adding the cancer drug Avastin to a treatment regimen for women with advanced ovarian cancer helped extend the time before the disease progressed, according to a new study presented Saturday.

Avastin, made by Roche's Genentech unit, is a drug designed to shut down blood vessels that fuel tumor growth.

The drug is approved in the US to treat colon, lung and other cancers, typically in addition to chemotherapy. Last year the US Food and Drug Administration revoked the approval of the drug for use in advanced breast cancer, saying the drug carried potentially life-threatening side effects and did not appear to slow the progression of breast cancer.

Roche has sponsored four clinical studies testing Avastin for use in treating ovarian cancer. Data from one of those studies will be presented Saturday at the American Society of Clinical Oncology's annual meeting in Chicago.

The study involved 361 patients whose disease had been previously treated with platinum-based chemotherapy but had not responded to treatment. Researchers then selected another type of chemotherapy for all the patients and about half of the patients also received Avastin.

Patients were followed for about 13.5 months to see how well their cancers responded to the treatment. The study showed about 75 percent of patients who received Avastin and chemotherapy had a cancer recurrence compared to 91 percent of patients who received chemotherapy alone.

The average time before the cancer started growing again after treatment began, a measure known as progression-free survival, was 6.7 months in the Avastin group compared to 3.4 months in the chemotherapy-only group. Data on how long patients actually lived, a measure called overall survival, has not matured but is expected to be available next year.

The study showed side effects were greater in the Avastin group. High blood pressure was seen in about 20 percent of Avastin patients compared to seven percent of patients receiving chemotherapy. There was also a slightly higher rate of gastrointestinal perforations -- when a hole develops through the wall of the stomach or intestines.

The study's lead author, Eric Pujade-Lauraine, the head of the Group d'Investigateurs Nationaux pour l'Etude des Cancers Ovariens, a clinical trials cooperative group based in France, said the study findings are important because is the first time an improvement has been shown using a combination of drugs in women with platinum-resistant ovarian cancer.

Avastin had been approved in the US as breast cancer treatment, partly based on one study that showed about a five-month improvement in disease progression, or median progression free survival, compared to patients not receiving the drug. There was also a requirement that the company keep studying the drug and submit it to FDA. The additional study information showed the difference between patient groups with breast cancer was small, prompting the FDA to withdraw the drug's approval in breast cancer.

Carol Aghajanian, chief of the gynecologic medical oncology service at Memorial Sloan-Kettering in New York, who led a different Avastin study in ovarian cancer, said data looking at Avastin in ovarian cancer is so far consistently showing that adding the drug to treatment is slowing disease progression, while the data in breast cancer was mixed.