The anti-cancer drug bevacizumab (Avastin) added recurrent and metastatic cervical cancer to its list of late last week.
Cervical cancer, usually caused by the sexually transmitted human papillomavirus, can be stopped if it's caught early, but it can progress in women who don’t get regular cervical exams. Once the cancer spreads, or metastasizes, survival rates dip below one in six. More than 12,000 Americans with cervical cancer in 2014, and one-third are expected to die from the disease.
Bevacizumab is the first drug approved for tough-to-treat cervical cancer cases since 2006, according to the Food and Drug Administration (FDA). In a clinical trial, the drug, combined with earlier chemotherapy drugs, prolonged survival by 30 percent.
“Until today, chemotherapy was the only approved treatment option for women whose cancer recurred, persisted, or spread,” said Dr. Sandra Horning, chief medical officer at Genentech, the San Francisco company that makes Avastin.
A Winding Road to Approval
The drug’s record of approvals for various types of cancer — and a memorable withdrawn approval for breast cancer — charts a path through the changing approaches to cancer research in the past two decades.
Bevacizumab belongs to a relatively new class of drugs, called monoclonal antibodies. Monoclonal antibodies are genetically engineered biologic substances that help the immune system fight a very specific target. Bevacizumab targets vascular endothelial growth factor, which helps new blood vessels grow.
In the last decades of the 20th century, cutting off the blood vessels that feed tumors and help them grow was as a silver bullet to treat cancer. But confidence in the approach had begun to wane by 2004, after several promising drugs failed in clinical trials.
That year, bevacizumab became the first drug approved to accomplish the task, specifically targeting metastatic colorectal cancer.
Approvals for lung cancer and the brain cancer glioblastoma followed. In 2008, the drug was granted “accelerated approval” as a treatment for metastatic breast cancer, meaning that Genentech could begin selling the drug to patients before it had proven that it would help them live longer. Genentech was required to submit more data after sales began, but those studies showed that the drug had no meaningful benefits for patients.
FDA Commissioner Dr. Margaret Hamburg yanked the drug's approval in 2011, even as some breast cancer patients pleaded for her not to, believing that it had saved their lives.
“As a patient advocacy organization, we want to ensure that women who are successfully using Avastin today continue to have access to the drug,” Elizabeth Thompson, then president of the patient advocacy organization Susan G. Komen for the Cure, said at the time.
The group's appeal was based on another new technique — dividing cancer patients by genetic markers. Thompson suggested that further research might prove that women with certain genetic traits or cancer types could respond to the drug, even though studies on a general population of breast cancer patients were not successful.
A Second Chance to Treat Women's Cancers
Though bevacizumab remains out in the cold when it comes to breast cancer, it has since gained another approved use, for late-stage kidney cancer.
And with its recent green light for cervical cancer, Genentech gets another chance to stand behind a drug that treats women’s cancers. Researchers are also exploring whether the drug might work on ovarian cancer.