Avastin (bevacizumab), a new type of cancer medication, has been approved for colon, lung, kidney and brain cancer. Off-label use of Avastin for eye diseases has caused blindness in some patients. In November 2011, the FDA revoked Avastin’s breast cancer approval, because it is not more effective than other drugs, but has serious side effects (blood clots, ovarian failure, and jaw deterioration). Avastin may still be used as an “off label” treatment in spite of the risks and numerous FDA warnings.
UPDATE: FDA Warning for Avastin Eye Infections
March 20, 2013 — The FDA and a compounding pharmacy have issued a recall after contaminated lots of Avastin were linked to 5 cases of eye infections. Click here to read more.
What is Avastin?
Avastin (bevacizumab) was created by Genentech, Inc. and received FDA approval for the treatment of malignant colorectal cancer in 2005. Avastin has shown effectiveness against a wide range of cancers, and has subsequently gained approval for lung cancer (2006), breast cancer (2008), brain cancer (2009), and kidney cancer (2009).
Avastin inhibits the growth of cancerous tumors by inhibiting an enzyme necessary for the formation of blood vessels, in a process known as angiogenesis. Avastin is the first FDA-approved drug in this class of cancer drugs, and since its approval in 2005, has become one of the most popular and successful cancer drugs in history. Early trials of the drug were exceptionally promising. Colorectal cancer patients who took Avastin while on chemotherapy lived about five months longer than cancer patients only on chemotherapy.
Avastin was accelerated through the FDA approval process in the hopes that it would be effective against many types of cancer. During the accelerated FDA approval process, a drug receives probationary approval so that patients who are dying have access to the newest drugs. While more thorough research is conducted, the FDA can revoke a drug’s approval at any time. This approval method has received criticism, because the risks and benefits of new drugs are not fully known by a patient’s physician.
Avastin effectiveness against colorectal cancer was particularly exciting, because colorectal cancer is the third most common cancer in the U.S., the second leading cause of cancer-related death, and one of the most common cancers in the U.S. — in 2003, approximately 147,500 new cases were diagnosed.
Avastin Causing Blindness in “Off-Label” Use
On August 30, 2011, the FDA issued a safety warning after confirming 12 more reports of blindness caused by doctors using the cancer drug Avastin to treat eye diseases. Avastin is not approved for the treatment of eye diseases.
Doctors commonly prescribe Avastin to treat age-related macular degeneration and other eye diseases because each dose costs roughly $50/injection, compared with using Lucentis, which has been approved for the treatment of eye diseases but costs $2000/injection. It is thought that the cause of blindness is bacterial contamination, because the vials of Avastin must be repackaged into smaller doses for injection into the eye.
Avastin Breast Cancer Approval Revoked
On November 18, 2011, the FDA officially revoked Avastin’s approved indication for breast cancer. The official decision comes five months after an advisory committee recommended that the FDA withdraw Avastin’s indication for breast cancer.
The official decision has been anticipated since Avastin failed Phase III clinical trials in 2010 because it showed no survival benefit and carried a high risk of severe side effects. Though the trials showed an 18% increased response rate, there was no difference in the rate of people who had died of breast cancer at 25 months.
Side Effects & FDA Safety Warnings
Avastin side effects include:
- Severe high blood pressure
- Jaw deterioration
- Bleeding and hemorrhaging
- Heart attack or heart failure
- Perforations of the nose, stomach, and intestines.
On September 30, 2011, the FDA updated Avastin’s safety label to include new evidence of serious side effects:
- Ovarian Failure. 34% of women receiving Avastin experienced ovarian failure, as compared to 2% of women receiving only chemotherapy.
- Venous Thrombolic Events (VTE). 27.5% of patients with metastatic colorectal cancer expeirenced serious bleeding, as opposed to 20.9% in the patients receiving only chemotherapy.
- Osteonecrosis of the jaw (ONJ). This is a severe disease that occurs when facial bones do not receive enough blood and they begin to die. Physicians believe that this effect is caused by the anti-angiogenic properties of Avastin.
More FDA Safety Warnings:
- September 27, 2006 – The FDA and Genentech, Inc. issued a safety warning after finding evidence of an increased risk of reversible posterior leukoencephalopathy syndrome (RPLS), a rare brain-capillary leak syndrome associated with hypertension, fluid retention, and cytoxic effects of immunosuppressive drugs on the vascular endothelium.
- August 12, 2004 — The FDA and Genentech issued a safety warning after finding an increased risk of serious arterial thrombolic events, including cerebrovascular accident, myocardial infarctions, transient ischemic attacks, angina, and fatal arterial thrombotic events. The risks of a serious arterial thrombotic event was approximately two-fold higher in patients taking Avastin, with an estimated overall rate of up to 5 percent.