Avastin (Bevacizumab): Good or Bad Cancer Treatment?
Dr. Richard Frank—
I recently met a patient who asked me to be his oncologist, requesting a change from his present oncologist. I knew that his oncologist was a skilled and kind physician so I wondered why.
“Why would you like me to be your doctor now?” I asked.
“Because Dr. X wanted to give me that drug Avastin! The FDA has just taken away approval for that drug. He wants to give me a useless therapy, so I have no faith in him,” he replied.
“But you have colon cancer and Avastin is approved for that use and can improve the effectiveness of chemotherapy. Its rejection by the FDA was only in breast cancer.”
“Still, I don’t want it. I read the New York Times articles on it and it doesn’t work,” he said.
We chatted for awhile longer and I tried to get him to understand that one drug can have different effects on different cancers, work for some, fail for others. I convinced him to go back to his regular oncologist, who had recommended an appropriate treatment for him.
Avastin works by diminishing the blood flow to a cancerous tumor and often helps chemotherapy to work. So is Avastin a useful drug against cancer? There are different ways of looking at this question. At the level of drug approval, Avastin is FDA approved to treat a variety of cancers including metastatic colorectal, lung, and kidney cancer as well as glioblastoma (a brain tumor). It gained this approval in the first two because it improved overall suvival of patients when added to chemotherapy (the benefit was 4-5 months for colorectal and 2 months for lung). In the case of glioblastoma, the FDA approved it based on small trials showing a benefit in a cancer that desperately needs new treatments (the gold standard randomized, phase III trial was not required). The drug was approved for use in metastatic breast cancer when one trial did show an overall survival benefit but this approval was overturned when additional clinical trials failed to demonstrate a similar benefit; also the drug has toxicities so if there is not a real benefit, then the risks outweight the gains and it is best not used.
The drug is not FDA approved for ovarian cancer although it is commonly used now to treat this cancer. In other cancers, such as metastatic pancreatic and prostate, the trials with Avastin failed to show a meaningful benefit, so the drug is not used in these diseases. Basically, at this point, Avastin has been tested against every common cancer; it is helpful in some and not helpful in others.
As a single agent to treat cancer, Avastin is just not very potent. From both the published literature and my personal experience in treating a variety of cancer patients (and talking with colleagues who treat the cancers that I do not), I will state that overall, Avastin cannot actually shrink or control colon, lung or breast cancer without the addition of chemotherapy. It can however control/stabilize or even shrink, for a period of time, glioblastomas and ovarian cancers that have been previously treated. I have actually been quite impressed with the ability of single agent Avastin to shrink and control for six months or more, advanced, heavily pre-treated ovarian cancer.
All of the above aside, Avastin may still benefit some individuals with breast cancer. The big problem is we cannot predict who they are. Many patients petitioned the FDA to retain access to Avastin because they believe the drug is benefiting them; I have no doubt that this is true (it would be optimal if the FDA could find a way to allow such patients to continue the drug that is clearly benefiting them). But the FDA has made a decision that not enough patients benefit or we cannot determine ahead of time who they are, so Avastin cannot be recommended across the board for all patients with advanced breast cancer, especially in light of the possible severe side effects with the drug and its exorbitant cost.
The cost of cancer medicines is breaking the banks of Medicare and patients (private insurers continually raise their rates to cover costs) as well as forcing the closing of many oncology practices across the country. Access to basic cancer care and medicines is being jeopardized because of the exorbitant costs of the new biologic medicines. Unless these medicines can show at least a meager, repeatable improvement in survival for patients battling cancer, then they should not be approved and patients should not be given them in false hope.
Richard C. Frank, M.D., is director of cancer research at the Whittingham Cancer Center of Norwalk Hospital, medical director of Mid-Fairfield Hospice, and Clinical Assistant Attending at Weill Cornell Medical College. He has been appointed cancer expert for WebMD and was named a “Top Doc” in the New York Metro area by Castle and Connelly.