Bevacizumab (Avastin) improved progression-free survival (PFS) in patients with ovarian cancer but was not shown to affect overall survival (OS), according to a new study published in The New England Journal of Medicine.

As a result, Genentech, which is developing the drug, may not seek FDA approval for a new indication for ovarian cancer.

In the double-blind, placebo-controlled phase III study, 1873 patients with previously untreated advanced-stage ovarian cancer were separated into 3 study arms. Patients in 1 arm received bevacizumab with chemotherapy (intravenous paclitaxel plus carboplatin), followed by bevacizumab for up to 10 months. Participants in a second arm received the same chemotherapy but were given a placebo instead of bevacizumab, while those in the third arm received bevacizumab with chemotherapy but did not receive bevacizumab after the initial treatment.

The median PFS was 14.1 months (hazard ratio [HR] = 0.717; 95% CI, 0.625-0.824; P <.001) with bevacizumab throughout, as compared with 11.2 months (HR = 0.908; 95% CI, 0.795-1.040; P = .16) in the bevacizumab initiation group and 10.3 months in the control arm. At the time of the analysis, 76.3% of patients were still alive, but the authors reported no significant differences in OS among the 3 groups.

“This approach can be looked upon as a third major component of treatment for ovarian cancer and related malignancies,” said Robert A. Burger, MD, lead investigator on the Gynecologic Oncology Group study and director of the Women’s Cancer Center at Fox Chase Cancer Center, Philadelphia, Pennsylvania, in a statement. “We’ve had the combination of surgical management and cytotoxic chemotherapy for many years, but we haven’t really seen anything else in terms of a fundamental class of treatment. This represents a new way for us to control the disease.”

Hypertension was the most prominent adverse event associated with bevacizumab, with 22.9% of patients in the bevacizumab-throughout group and 16.5% of patients in the bevacizumab-initiation group requiring medical therapy to manage the side effect, compared with 7.2% in the control group.

While bevacizumab is already approved by the FDA for use in certain types of brain, colon, kidney, and lung cancers, Genentech said there is a “low likelihood” that the company will submit the latest data for a new indication for ovarian cancer. “A final decision will be made following internal assessment of full data from the phase III trials,” a company spokeswoman said.

In December, the European Commission approved the drug in combination with chemotherapy for women with late-stage ovarian cancer as firstline treatment following surgery, marking the first advance in newly diagnosed patients in 15 years.