Officials with Genentech Inc., the South San Francisco company that makes Avastin, expressed disappointment with the FDA's action but said a new Phase 3 clinical trial would begin soon to further evaluate how the medication works with paclitaxel. In addition, research will proceed on the search for biomarkers that may indicate whether a particular woman is likely to benefit from the drug.
Some researchers said they still believed it may help certain subgroups of women with breast cancer, such as people with so-called triple-negative disease, which is a particularly aggressive form.
"This is definitely not the end of the story for Avastin and breast cancer," said Dr. Neal Meropol, chairman of the American Society of Clinical Oncology's comparative effectiveness research task force and an oncologist at University Hospitals Case Medical Center in Cleveland. "It's quite likely there is a subset of patients who benefit from Avastin to a major degree. The challenge for us is to identify which patients with breast cancer will benefit."
But Meropol said that he agreed with the FDA's decision and applauded the time and diligence the agency gave in weighing the matter.
"I think the FDA made a very reasoned decision based on the scientific data as well as input from experts, patients and the people who make Avastin," he said.
Patient groups were divided on the decision, largely because of how insurers will deal with the issue.
Leaders of the Ovarian Cancer National Alliance, based in Washington, worried that the removal of Avastin's indication for breast cancer might harm women with ovarian cancer who receive the medication off-label.
Some breast cancer patient advocates have harbored doubts about Avastin in spite of its popularity.
"Our position from the very beginning is that they should not have given this particular drug approval for breast cancer," said Fran Visco, president of the National Breast Cancer Coalition in Washington, who applauded the decision.
The loss of Avastin in the breast cancer treatment arsenal should not concern patients, since they can still receive chemotherapy, Mortimer said. "There are so many new drugs coming out for treatment of breast cancer."
Alexa Vaughn in the Washington bureau contributed to this report.