Immunotherapy for Colorectal Cancer
Types of Immunotherapy continued...
Also in February 2004, the FDA approved another first-of-its-kind monoclonal antibody called Avastin (bevacizumab). This drug works by shutting down a process called angiogenesis -- the process whereby tumors grow new blood vessels to help them receive the nutrients needed to survive. It's approved to treat advanced colorectal cancer that has spread to other organs.
In March of 2007 the FDA approved the drug Vectibix (panitumumab), which is similar to Erbitux for treating colorectal cancer that has spread.
The drugs cetuximab and panitumumab must be used in patients who do not have a mutation of a gene in their colon cancer known as K-ras. If this gene is present these drugs won’t work. Individuals with advanced colon cancer should routinely be checked for K-ras.
Bevacizumab attacks the blood supply of the cancer. Currently, doctors can't predict which patients who will respond best to it.
What Are the Side Effects of Immunotherapies?
Like other forms of cancer treatment, immunotherapies can cause a number of side effects. These side effects can vary widely from person to person. Biologic response modifiers may cause flu-like symptoms including fever, chills, nausea, and loss of appetite. In addition, rashes or swelling may develop at the site where they are injected and blood pressure may drop as a result of treatment. Fatigue is another common side effect of biologic response modifiers. In addition:
- Side effects of colony-stimulating factors may include bone pain, fatigue, fever, and loss of appetite.
- The side effects of monoclonal antibodies vary and serious allergic reactions may occur.
- Vaccines can cause muscle aches and low-grade fever.
- Rashes are a common and may be a severe side effect of Erbitux or Vectibix. Rashes are usually indicative that these drugs are working. They are a side effect of the drugs, not an allergy.
- Bleeding, blood clotting, or bowel perforation may occur as a side effect of Avastin.
Talk to your doctor to learn if immunotherapy is right for you.