Cancer Drug Avastin Makes Inroads Against Ovarian Tumors
Two studies show some benefit, but drug's high price tag may be prohibitive, one expert says
SATURDAY, June 4, 2011 (HealthDay News) -- Two new studies indicate that a common cancer drug, Avastin, may benefit both early stage ovarian cancer patients and women whose cancer has recurred.
In both studies, presented Saturday at the annual meeting of the American Society of Clinical Oncology in Chicago, Avastin (bevacizumab) was added to standard chemotherapy.
But the high cost of Avastin (as much as $6,000 a month) could be prohibitive, especially given that other therapeutic options are available to women in each group, said Dr. Kristine Zanotti, a gynecologic oncologist with University Hospitals of Cleveland.
"This is interesting but not practice-changing," she said. Zanotti was not involved with the research.
According to the American Cancer Society, ovarian cancer is the fifth most common cancer among women, but it is especially deadly because it is often caught too late for effective treatment. Nearly 14,000 American women died of ovarian cancer in 2010, the cancer society said.
The first of the two studies tracked 484 women whose ovarian malignancies had recurred but who had a relatively good prognosis based on their response to earlier chemotherapy.
Participants were randomly chosen to receive standard chemotherapy alone or chemotherapy plus Avastin. The Avastin (or placebo in the placebo arm) treatment was continued after the end of chemotherapy until the disease returned, at which point it was stopped.
After two years, investigators saw a 52 percent reduction in the risk of a recurrence, or 12.4 months in those patients taking Avastin, compared to 8.4 months in the standard chemo-alone group.
Almost 80 percent of women receiving Avastin saw their tumors shrink, compared to 57 percent of those receiving chemotherapy alone. The tumors in the Avastin group also stayed smaller for longer, the research team noted.
The side effects from Avastin were what would have been expected, including hypertension and low white blood cell counts but not intestinal perforations, the researchers said. The study was funded by Genentech, an American subsidiary of drug maker Roche, which makes Avastin.
"This [treatment] provides a clinically meaningful benefit in the recurrence of ovarian cancer," study lead author Dr. Carol Aghajanian, chief of the Gynecologic Medical Oncology Service at Memorial Sloan-Kettering Cancer Center in New York City, said at a Saturday news conference. "This regimen should be considered a new option [for this group of patients]," she added.
The data did not show a benefit in overall patient survival, although the researchers aren't ruling it out with longer follow-up. So that fact, plus the issue of cost, need to be taken into account when deciding if adding Avastin is appropriate, said Zanotti.
"Adopting [Avastin] as a new clinical paradigm would introduce an exceptional cost for caring for these patients without really any identified survival benefit," she said. "My [reasoning] is that we can easily achieve results with a lot less therapy and tremendously less cost."
The second trial was funded by Roche. It involved more than 1,500 women with newly diagnosed high-risk or advanced ovarian cancer who were randomized to receive chemotherapy alone or chemotherapy along with Avastin. In the latter group, Avastin was continued after the end of chemotherapy as "maintenance" therapy.
After an average follow-up of 28 months, progression-free survival was improved in the Avastin group but overall survival was not meaningfully changed, the researchers reported. Again, though, the team isn't ruling out that a survival benefit might emerge as more data is collected over time.
There was a statistically significant reduction in deaths involving patients with more dire cancer, a decline of 36 percent.
"This may be of clinical relevance in high-risk patients," said Dr. Gunnar Kristensen, one of the lead investigators of the study and senior consultant in the department for gynecologic oncology at Norwegian Radium Hospital in Oslo, Norway. "The final data on overall survival is due in 2013."
However, the lack of an overall survival benefit must again be weighed against the Avastin's high price tag, Zanotti stressed again.
"They show that they can delay recurrence but they [haven't] improved survival," she said, adding that the findings on the high-risk population were "intriguing."
"These are harder to treat [cancers] and we are searching for effective therapies," Zanotti said.
There's more on ovarian cancer at the U.S. National Cancer Institute.